Journal of Arthroplasty

Temporal Trends and Predictors of Thirty-Day Readmissions and Emergency Department Visits Following Total Knee Arthroplasty in Ontario Between 2003 and 2016

17-11-2019 – Tayler D. Ross, Erind Dvorani, Refik Saskin, Amir Khoshbin, Amit Atrey, Sarah E. Ward

Journal Article

Background

Total knee arthroplasty (TKA) is the second most common surgery performed in Canada. Understanding and improving quality metrics associated with such high-volume procedures is of utmost importance to maximize value within the healthcare system, which is a balance between cost and quality. Although rates and predictors of hospital readmission and emergency department (ED) visits following TKA have previously been described in privatized healthcare settings, few studies have evaluated trends in length of stay (LOS), hospital readmissions, and ED visits following TKA in a universal single-payer system.

Methods

Using data from a provincially held and validated registry, the Institute for Clinical and Evaluative Sciences, we undertook a review of all 205,152 TKAs performed in the province of Ontario, Canada, between 2003 and 2016. We determined temporal trends in utilization, LOS, readmissions, and ED visits and evaluated patient and provider predictors of hospital readmissions and ED visits using multivariate logistic regression modeling. We also grouped and described the most common reasons for readmission and ED visits based on the available International Classification of Diseases, Ninth Revision and Tenth Revision coding information.

Results

LOS decreased significantly over the study period (P < .0001), from a median of 5 days (10th percentile 3 days, 90th percentile 8 days) in 2003 to a median of 3 days (10th percentile 2 days, 90th percentile 4 days) in 2016. All-cause 30-day readmissions did not change significantly over the study period, but the rate of ED visits increased significantly over time. Predictors of 30-day readmission following TKA included older age, male gender, lower income quartile, not having a postoperative visit with a primary care physician (PCP), increased comorbidities, longer LOS, urgent or revision surgery, admission to a teaching hospital, and discharge to an inpatient rehabilitation facility. Variables that predicted increased odds of an ED visit included older age, male gender, lower income quartile, not having a postop visit with a PCP, increasing comorbidities, year of surgery, longer LOS, and revision surgery. Admission to a teaching hospital and discharge to an inpatient rehabilitation facility showed a trend toward increased odds of an ED visit.

Conclusions

We identified a significant increase in ED visits following TKA in Ontario between 2003 and 2016, with no corresponding increase in hospital readmissions despite a significant temporal trend toward shorter LOS. Predictors of ED visits and readmissions were similar, including male gender, lower income, higher comorbidities, and lacking a PCP visit postoperatively. Increased rates of ED visits following TKA in Ontario represent a quality problem, as they are associated with increased cost to the public healthcare system without any substantial benefit. Interventions aimed at redirecting patients from the ED for minor postoperative concerns should be investigated, as this is likely to improve care by reducing costs, improving efficiency, and enhancing patient experience.

Inxa0Vivo Determination and Comparison of Total Hip Arthroplasty Kinematics for Normal, Preoperative Degenerative, and Postoperative Implanted Hips

24-09-2019 – Charles A. DeCook, Michael T. LaCour, Jarrod K. Nachtrab, Milad Khasian, Garett M. Dessinger, Richard D. Komistek

Journal Article

Background

The study objective is to analyze subjects having a normal hip and compare in vivo kinematics to subjects before and after receiving a total hip arthroplasty.

Methods

Twenty subjects, 10 with a normal hip and 10 with a preoperative, degenerative hip were analyzed performing normal walking on level ground while under fluoroscopic surveillance. Seven preoperative subjects returned after receiving a total hip arthroplasty using the anterior surgical approach by a single surgeon. Using 3-dimensional to 2-dimensional registration techniques, joint models were overlayed on fluoroscopic images to obtain transformation matrices in the image space. From these images, displacements of the femoral head and acetabulum centers were computed, as well as changes in contact patches between the 2 surfaces throughout the gait cycle.

Results

Implanted hips experienced the least amount of separation, compression, and overall sliding throughout the entire gait cycle, but they did show signs of edge loading contact patterns. Conversely, the degenerative hips experienced the most compression, sliding, and separation, with the maximum amount of sliding being 6.9 mm. The normal group ranged in the middle, with the maximum amount of sliding being 1.75 mm.

Conclusion

Current analysis revealed trends that degenerative hips experience more abnormal hip kinematics that leads to higher articulating surface forces and stresses within the acetabulum. None of the implanted hips experienced hip separation.

Tibial Implant Fixation Behavior in Total Knee Arthroplasty: Axa0Study With Five Different Bone Cements

28-10-2019 – Thomas M. Grupp, Christoph Schilling, Jens Schwiesau, Andreas Pfaff, Brigitte Altermann, William M. Mihalko

Journal Article

Background

The objectives of this study are to (1) evaluate if there is a potential difference in cemented implant fixation strength between tibial components made out of cobalt-chromium (Cr
Co
Mo) and of a ceramic zirconium nitride (Zr
N) multilayer coating and to (2) test their behavior with 5 different bone cements in a standardized in vitro model for testing of the implant-cement-bone interface conditions. We also analyzed (3) whether initial fixation strength is a function of timing of the cement apposition and component implantation by an early, mid-term, and late usage within the cement-specific processing window.

Methods

An in vitro study using a synthetic polyurethane foam model was performed to investigate the implant fixation strength after cementation of tibial components by a push-out test. A total of 20 groups (n = 5 each) was used: Vega PS Cr
Co
Mo tibia and Vega PS Zr
N tibia with the bone cements Bon
Os R, Smart
Set HV, Cobalt HV, Palacos R, and Surgical Simplex P, respectively, using mid-term cement apposition. Three different cement apposition times—early, mid-term, and late usage—were tested with a total of 12 groups (n = 5 each) with the bone cements Bon
Os R and Smart
Set HV.

Results

There was no significant difference in implant-cement-bone fixation strength between Cr
Co
Mo and Zr
N multilayer-coated Vega tibial trays tested with 5 different commonly used bone cements.

Conclusion

Apposition of bone cements and tibial tray implantation in the early to mid of the cement-specific processing window is beneficial in regard to interface fixation in TKA.

Postmortem Retrieval Analysis of Metallosis and Periprosthetic Tissue Metal Concentrations in Total Knee Arthroplasty

09-11-2019 – Christina M. Arnholt, Joshua B. White, Julie A. Lowell, Meredith R. Perkins, William M. Mihalko, Steven M. Kurtz

Journal Article

Background

The purpose of this study is to determine the preferred sampling location for tissue analysis in total knee arthroplasty (TKA) and to evaluate metal concentrations, inflammatory cytokines, component damage, and tissue metallosis.

Methods

Twenty TKA systems were collected at necropsy along with tissue samples from 5 distinct locations. Inductively coupled plasma mass spectrometry (ICP-MS) analysis was performed to determine cobalt (Co), chromium (Cr), and titanium (Ti) concentrations. Synovial fluid cytokine analysis was preformed using a Magnetic Luminex Screening Assay. Femoral components were assesed for damage and tissues were visually scored for metallosis.

Results

The median metal concentrations were 16 ppb for Co, 46 ppb for Cr, and 9.8 ppb for Ti. There was no association between the tissue collection site and the metal concentration for Co (P = .979), Cr (P = .712), or Ti (P = .854). Twelve of 20 of the necropsy-retrieved TKAs had metallosis, but there was no correlation between Co (P = .48), Cr (P = .89), or Ti (P = .60) concentration and metallosis. Increased Co was associated with decreased tumor necrosis factor alpha (ρ = −0.56, P = .01) and interleukin 1 beta (ρ = −0.48, P = .03). Increased Cr was associated with decreased tumor necrosis factor alpha (ρ= −0.47, P = .03), interleukin 6 (ρ= −0.43, P = .04), and macrophage inflammatory protein 3 alpha (ρ= −0.47, P = .03).

Conclusion

We observed elevated Co, Cr, and Ti concentrations in tissue from necropsy-retrieved TKA. Our findings did not support the hypothesis that tissue metal concentrations were associated with inflammatory cytokines. The results of this research will be useful for the design of future prospective studies.

Asymptomatic Deep Venous Thrombosis After Elective Hip Surgery Could Be Allowed to Remain in Place Without Thromboprophylaxis After a Minimum 2-Year Follow-Up

26-09-2019 – Kosuke Tsuda, Masaki Takao, JungHyo Kim, Hirohito Abe, Nobuo Nakamura, Nobuhiko Sugano

Journal Article

Background

It is not clear how to treat asymptomatic deep venous thromboses (DVTs) following elective hip arthroplasty because the natural course of DVTs is unclear. It is therefore valuable to understand the natural course of DVTs and their relation to thromboprophylactic methods.

Methods

We followed 742 consecutive patients who underwent elective hip arthroplasty followed by mechanical or chemical prophylaxis of a DVT. All patients underwent preoperative and postoperative duplex ultrasonography of both limbs. Patients who developed postoperative DVT in the popliteal or calf vein were followed without thromboprophylaxis. DVT-positive patients were prospectively followed up with duplex ultrasonography at 3, 6, 12, and 24 months postoperatively.

Results

Incidences of preoperative and postoperative DVTs were 3.9% and 33.0%, respectively. Nonfatal pulmonary embolism (PE) occurred in 1 patient after negative echography. All DVTs that developed in the calf vein postoperatively and without anticoagulation remained benign, and 93% of the DVTs ultimately disappeared.

Conclusion

These results confirmed that the natural course of asymptomatic distal DVTs is benign, with no risk of leading to PE. Thus, distal DVTs could be allowed to remain untreated without chemical prophylaxis to prevent PE in Asian populations.

Is Pseudo-Patella Baja Really a Serious Complication of Total Knee Arthroplasty?

17-10-2019 – Alfredo Aguirre-Pastor, David J. Ortolá, Alejandro Lizaur-Utrilla, Michele A. Rosa, Fernando A. Lopez-Prats

Journal Article

Background

The available evidence on pseudo-patella baja (PPB) is limited. The purpose of this study is to investigate prospectively the occurrence of PPB after primary total knee arthroplasty and its clinical consequences in a large series of patients with a minimum follow-up of 2 years. PPB was defined as a patella distally displaced in relationship to the femoral trochlea with absence of patellar tendon shortening (Grelsamer RP. J Arthroplasty 2002;17:66-69) due to elevation of the joint line.

Methods

This study is a prospective case series of 354 patients with a mean age of 71.7 (range 52-87) years. Clinical evaluation was performed by the Knee Society Scores (KSS), Western Ontario and Mc
Master Universities Osteoarthritis Index (WOMAC), Short-Form 12-item (SF12), and range of motion. Patellar height was assessed by the Insall-Salvati and Blackburne-Peel ratios.

Results

The mean follow-up was 3.6 (range 2.0-6.6) years. Postoperatively, 286 (80.7%) patients had a normal patellar height, 17 (4.8%) had true patella baja (TPB), and 51 (14.4%) had PPB. There were no significant differences between the 3 groups in mean KSS-function (P = .107), range of motion (P = .408), WOMAC-pain (P = .095), WOMAC-stiffness (P = .279), or SF12-mental (P = .363). Between normal and PPB groups, there were no significant differences in mean KSS-knee (P = .903), WOMAC-function (P = .294), or SF12-physical (P = .940). However, the TPB group had significantly lower mean KSS-knee (P = .031), WOMAC-function (P = .018), and SF12-physical (P = .005) as compared with either 2 other groups.

Conclusion

PPB was a relatively common finding, but no significant differences in terms of clinical outcomes were found as compared to patients with postoperative normal patellar height. TPB was infrequent, but these patients had significantly worse clinical outcomes than those with PPB or normal patellar height.

Geniculate Artery Embolization in Patients With Recurrent Hemarthrosis After Knee Arthroplasty: A Retrospective Study

12-10-2019 – Elisa G.R. Luyckx, Annelies M.P. Mondelaers, Thijs van der Zijden, Maurits H.J. Voormolen, Frans R.A. Van den Bergh, Olivier C. d’Archambeau

Journal Article

Background

Recurrent hemarthrosis after knee arthroplasty is an uncommon and disabling complication of this frequently performed procedure. Selective endovascular embolization of the geniculate arteries is one of the therapeutic options to manage this complication. The purpose of this study is to analyze the effectiveness of this treatment in patients suffering from recurrent hemarthrosis after knee arthroplasty.

Methods

We performed a retrospective study of 31 patients (39 embolization procedures) with recurrent hemarthrosis after knee arthroplasty. There were 17 men and 14 women with a median age of 67 years (range 48-90). All patients were referred for geniculate artery embolization between January 2007 and November 2016.

Results

Twenty-seven procedures were executed on the right side and 12 on the left side. Total knee arthroplasty was performed on 29 patients, only 2 patients underwent unicompartmental knee arthroplasty. Embolization of the superior geniculate arteries was achieved in all patients. In 12 of 39 procedures (31%), at least 1 of the inferior geniculate arteries could not be catheterized, therefore embolization was achieved through collaterals. Symptomatic improvement was observed in 26 of 31 patients (84%). Discomfort or mild postprocedural pain was observed in most patients, needing only minor pain medication, mostly resolving within 24 hours. Two patients presented with a severe complication: a 48-year-old male patient developed septic arthritis and an 85-year-old hypertensive female patient treated with anticoagulants showed aseptic necrosis of the femoral condyles.

Conclusion

Embolization of geniculate arteries is a safe and effective treatment in recurrent hemarthrosis post knee arthroplasty. Clinical improvement was seen in most patients.

Persistent Fistula for Treatment of a Failed Periprosthetic Joint Infection: Relic From the Past or a Viable Salvage Procedure?

16-10-2019 – Florian Troendlin, Sven Frieler, Yannik Hanusrichter, Emre Yilmaz, Thomas A. Schildhauer, Hinnerk Baecker

Journal Article

Background

New treatment algorithms for periprosthetic joint infections (PJIs) show high success rates in achieving permanent infection eradication with some degree of failure. Different salvage procedures are described, but there is no evidence for persistent fistula (PF). The purpose of this study was to analyze PF as a salvage procedure in patients with therapy-resistant PJIs.

Methods

This retrospective analysis included all patients treated with PF (2005-2018) in a maximum care center with PJI (knee or hip). The baseline parameters (age, sex, BMI) and other data (number of surgeries, pathogen spectrum, American Society of Anesthesiologists classification) were recorded. The function was documented using the Harris Hip Score, the Knee Society Score, and the quality of life using the SF-36 Health Survey.

Results

A total of 159 patients were included (80 ± 12 years) and subdivided into four groups: hip (n = 66), knee (n = 13), Girdlestone resection arthroplasty (n = 50), knee arthrodesis (n = 27). Patients stayed 111 ± 87 days in the hospital, underwent six operations and three revisions after establishing PF. The mean American Society of Anesthesiologists score was 2.7. The BMI was 31 ± 3 kg/m2 (P = .1). The follow-up was 2.8 ± 0.5 years including 27 patients. The Harris Hip Score and Knee Society Score were 38 and 34, respectively. SF-36 showed no significant difference.

Conclusion

The study showed poor outcomes regarding quality of life and the function of the infected joint. Therefore, the indication for establishing a PF in the treatment of PJI must be assessed very critically. PF is only an option for multimorbid patients with a limited life expectancy.

Dilute Betadine Lavage Reduces the Risk of Acute Postoperative Periprosthetic Joint Infection in Aseptic Revision Total Knee and Hip Arthroplasty: A Randomized Controlled Trial

03-10-2019 – Tyler E. Calkins, Chris Culvern, Denis Nam, Tad L. Gerlinger, Brett R. Levine, Scott M. Sporer, Craig J. Della Valle

Journal Article

Background

The purpose of this randomized, controlled trial is to determine whether dilute betadine lavage compared to normal saline lavage reduces the rate of acute postoperative periprosthetic joint infection (PJI) in aseptic revision total knee (TKA) and hip arthroplasty (THA).

Methods

A total of 478 patients undergoing aseptic revision TKA and THA were randomized to receive a 3-minute dilute betadine lavage (0.35%) or normal saline lavage before surgical wound closure. Fifteen patients were excluded following randomization (3.1%) and six were lost to follow-up (1.3%), leaving 457 patients available for study. Of them, 234 patients (153 knees, 81 hips) received normal saline lavage and 223 (144 knees, 79 hips) received dilute betadine lavage. The primary outcome was PJI within 90 days of surgery with a secondary assessment of 90-day wound complications. A priori power analysis determined that 285 patients per group were needed to detect a reduction in the rate of PJI from 5% to 1% with 80% power and alpha of 0.05.

Results

There were eight infections in the saline group and 1 in the betadine group (3.4% vs 0.4%, P = .038). There was no difference in wound complications between groups (1.3% vs 0%, P = .248). There were no differences in any baseline demographics or type of revision procedure between groups, suggesting appropriate randomization.

Conclusion

Dilute betadine lavage before surgical wound closure in aseptic revision TKA and THA appears to be a simple, safe, and effective measure to reduce the risk of acute postoperative PJI.

Level of Evidence

Level I.

Synovial Fluid Calprotectin for the Preoperative Diagnosis of Chronic Periprosthetic Joint Infection

23-09-2019 – Paolo Salari, Marco Grassi, Barbara Cinti, Nicoletta Onori, Antonio Gigante

Journal Article

Background

The diagnosis of periprosthetic joint infection (PJI) represents a challenge in clinical practice and the analysis of synovial fluid is a useful diagnostic tool. Calprotectin is an inflammatory biomarker widely used in the evaluation of chronic inflammatory diseases; however, little is known about its role in PJI. The purpose of this study is to determine the reliability of synovial calprotectin in the diagnosis of PJI.

Methods

Seventy-six patients with painful knee arthroplasty were included in this prospective observational study. Synovial fluid was analyzed for cell count, percentage of polymorphonuclear neutrophils, microbiological culture, leukocyte esterase strip test, alpha-defensin rapid test, and calprotectin immunoassay dosage. The 2018 Consensus Statements criteria for PJI were used as standard reference to define the presence of infection. Sensitivity, specificity, positive and negative likelihood ratio, and receiver-operation characteristic curve were calculated for calprotectin immunoassay test.

Results

By 2018 Consensus Statements criteria for PJI, 28 patients were considered infected, 44 patients were considered not infected, and 4 patients were classified as inconclusive. The calprotectin synovial fluid test resulted in 2 false-positive results and no false-negative results. The calprotectin synovial fluid test demonstrated a sensitivity of 100% (95% confidence interval CI 99.96-100) and specificity of 95% (95% CI 89.4-100) for the diagnosis of PJI. The positive likelihood ratio was 22 (95% CI 5.680-85.209) and the negative likelihood ratio was 0 (95% CI 0-0.292). The area under the receiver-operation characteristic curve was 0.996 (95% CI 94.3-100).

Conclusion

The present study suggests that synovial calprotectin immunoassay test has a high sensitivity and specificity in the diagnosis of knee PJI. Moreover, it is easily applied, quick and valuable in clinical practice.

Measuring Surgical Site Infection From Linked Administrative Data Following Hip and Knee Replacement

17-10-2019 – Lynn N. Lethbridge, C. Glen Richardson, Michael J. Dunbar

Journal Article

Background

Surgical site infections (SSIs) in hip and knee arthroplasty are increasing internationally. Current trends in SSI monitoring use single source administrative databases with data collection points commonly at 30 or 90 days. We hypothesize that SSI rates are being under-reported due to methodological biases.

Methods

Data from multiple administrative data sets were contrasted and compared to look at the 90-day SSI rates for hip and knee arthroplasty in a single province from 2001 to 2015. SSI rates were calculated over time by year, and the differences in infection rates between single and multiple administrative data sets were calculated as an estimate of under reporting rates of SSIs. Days until diagnosis was measured for those diagnosed with an infection within 1 year.

Results

Combining administrative data sets indicates that hospital-based data underestimate SSI rates by 0.44 (P < .0001) of a percentage point over all years, a clinically significant result given the overall infection rate of 2.2% over the period. Less than 50% of hip and knee arthroplasty was recorded as infected by 30 days and approximately 75% of cases were recorded as infected by 90 days.

Conclusion

Single source administrative data sets and short follow-up periods underestimate SSI rates. Administrative data sets should be combined and a minimum follow-up period of 90 days should be used to more accurately track SSI rates in hip and knee arthroplasty.

Cemented Proximal Femoral Replacement for the Management of Non-Neoplastic Conditions: A Versatile Implant but Not Without Its Risks

30-09-2019 – Christopher Fenelon, Evelyn P. Murphy, Stephen R. Kearns, William Curtin, Colin G. Murphy

Journal Article

Background

The demand for revision arthroplasty continues to grow. Proximal femoral bone loss poses a significant challenge to surgeons and proximal femoral replacements (PFRs) are one option to address this problem. The aim of our study is to assess the reoperation, complication, and mortality rates following PFR for treatment of non-neoplastic conditions.

Methods

A retrospective observational study was conducted of a consecutive group of patients treated with a PFR for non-neoplastic conditions between 2010 and 2018. Mortality was confirmed using the Irish national death events publication service.

Results

Over the 8-year study period, 79 PFRs in 78 patients were performed. Mean age of patients was 78.3 years (standard deviation 11.9), of which 37.2% were male. Periprosthetic fracture was the most common indication for PFR (63.3%). The 30-day mortality rate was 7.6% (6 patients), of which bone cement implantation syndrome occurred in 4 patients. One-year mortality was 12.7%. Complications occurred in 22.8%.

Conclusion

A cemented PFR is a versatile prosthesis in the armamentarium of a revision arthroplasty surgeon that allows immediate full weight-bearing. However, it may appropriately be considered a last resort procedure that poses specific risks that must be explained to patients and family. We present the short-term outcomes on one of the largest series of PFR to date.

Low Revision Rates at More Than 10 Years for Dual-Mobility Cups Cemented Into Cages in Complex Revision Total Hip Arthroplasty

24-09-2019 – Gary Sayac, Thomas Neri, Loïc Schneider, Rémi Philippot, Frédéric Farizon, Bertrand Boyer

Journal Article

Background

Instability and aseptic loosening are the two main complications after revision total hip arthroplasty (r
THA). Dual-mobility (DM) cups were shown to counteract implant instability during r
THA. To our knowledge, no study evaluated the 10-year outcomes of r
THA using DM cups, cemented into a metal reinforcement ring, in cases of severe acetabular bone loss. We hypothesized that using a DM cup cemented into a metal ring is a reliable technique for r
THA at 10 years, with few revisions for acetabular loosening and/or instability.

Methods

This is a retrospective study of 77 r
THA cases with severe acetabular bone loss (Paprosky ≥ 2C) treated exclusively with a DM cup (NOVAE STICK; Serf, Décines-Charpieu, France) cemented into a cage (Kerboull cross, Burch-Schneider, or ARM rings). Clinical scores and radiological assessments were performed preoperatively and at the last follow-up. The main endpoints were revision surgery for aseptic loosening or recurring dislocation.

Results

With a mean follow-up of 10.7 years 2.1-16.2, 3 patients were reoperated because of aseptic acetabular loosening (3.9%) at 9.6 years 7-12. Seven patients (9.45%) dislocated their hip implant, only 1 suffered from chronic instability (1.3%). Cup survivorship was 96.1% at 10 years. No sign of progressive radiolucent lines were found and bone graft integration was satisfactory for 91% of the patients.

Conclusion

The use of a DM cup cemented into a metal ring during r
THA with complex acetabular bone loss was associated with low revision rates for either acetabular loosening or chronic instability at 10 years.

Dual Mobility for Monoblock Metal-on-Metal Revision—Is It Safe?

31-10-2019 – Nicholas D. Colacchio, Clint J. Wooten, John R. Martin, John L. Masonis, Thomas K. Fehring

Journal Article

Background

Revision of monoblock metal-on-metal (Mo
M) total hip arthroplasty (THA) is associated with high complication rates. Limited revision by conversion to a dual mobility (DM) without acetabular component extraction may mitigate these complications. However, the concern for polyethylene wear and osteolysis remains unsettled. This study investigates the results of DM conversion of monoblock Mo
M THA compared to formal acetabular revision.

Methods

One hundred forty-three revisions of monoblock Mo
M THA were reviewed. Twenty-nine were revisions to a DM construct, and 114 were complete revisions of the acetabular component. Mean patient age was 61, 54% were women. Components used, acetabular cup position, radiographic outcomes, serum metal ion levels, and HOOS Jr clinical outcome scores were investigated.

Results

At 3.9 years of follow-up (range 2-5), there were 2 revisions (6.9%) in the DM cohort, 1 for instability and another for periprosthetic fracture. Among the formal acetabular revision group there was a 20% major complication rate (23/114) and 16% underwent revision surgery (18/114) for aseptic loosening of the acetabular component (6%), deep infection (6%), dislocation (4%), acetabular fracture (3%), or delayed wound healing (6%). In the DM cohort, there were no radiographic signs of aseptic loosening, component migration, or polyethylene wear. One DM patient had a small posterior metadiaphyseal femur lesion that will require close monitoring. There were no other radiographic signs of osteolysis. There were no clinically significant elevations of serum metal ion levels. HOOS Jr scores were favorable.

Conclusion

Limited revision with conversion to DM is a viable treatment option for failed monoblock Mo
M THA with lower complication rates than formal revision. Limited revision to DM appears to be a safe option for revision of monoblock Mo
M THA with a cup in good position and an internal geometry free of sharp edges or articular surface damage. Longer follow-up is needed to demonstrate any potential wear implications of these articulations.

Dual Mobility Cups in Revision Total Hip Arthroplasty: Efficient Strategy to Decrease Dislocation Risk

30-09-2019 – Axel Schmidt, Cécile Batailler, Camdon Fary, Elvire Servien, Sébastien Lustig

Journal Article

Background

Revision total hip arthroplasty (r
THA) is a challenging surgery with a higher rate of complications than primary arthroplasty, particularly instability and aseptic loosening. The purpose of this study is to compare dual mobility cup (DMC) and standard mobility cup (SMC) in all r
THAs performed at our institution over a decade with a 1 year minimum follow-up.

Methods

Two hundred ninety-five r
THAs (acetabular only and bipolar revisions) between 2006 and 2016 were retrospectively reviewed. These were divided into those with a DMC (184 revisions) or SMC (111 revisions). Dislocation and complications requiring re-revision were reported.

Results

The r
THA mean age was 69 years ± 13.9 (19-92) and the mean follow-up was 2.3 years. Dislocation risk was statistically lower (P = .01) with a DMC (3.8%; 7/184) than with an SMC (13.5%; 15/111). DMC required re-r
THA in 24/184 (13%) for any reason compared to SMC in 19/111 (17.1%) (P = .34). There was no significant difference in early aseptic loosening (P = .28) between the 2 groups. For young patients (≤55 years), results were similar with a lower dislocation rate in the DMC group (P = .24) and no increased risk of early aseptic loosening (P = .49).

Conclusion

This study demonstrates that for all r
THA indications DMC compared to SMC has a significantly decreased risk of postoperative dislocation without risk of early aseptic loosening at medium term follow-up. The use of DMC in r
THA is an important consideration particularly with the predicted increased incidence of both primary and revision THA globally.

Metaphyseal Sleeves in Revision Total Knee Arthroplasty Provide Reliable Fixation and Excellent Medium to Long-Term Implant Survivorship

14-10-2019 – Benjamin V. Bloch, Odei A. Shannak, Jeya Palan, Jonathan R.A. Phillips, Peter J. James

Journal Article

Background

Addressing bone loss and securing implant fixation can be challenging in revision total knee arthroplasty (TKA). We present the results of a large series of revision TKAs using a metaphyseal sleeve.

Methods

We retrospectively analyzed 319 revision TKAs with the use of a metaphyseal sleeve that had been followed up for at least 2 years, using a prospectively collected database. The mean follow-up was 91 months, and 73 patients were followed up for more than 10 years.

Results

Implant survivorship was 99.1% at 3 years, 98.7% at 5 years, and 97.8% at 10 years. No metaphyseal sleeve was revised for aseptic loosening. Final radiographic review showed that there were radiolucent lines present in 2.8% of tibial sleeves and 2.7% of femoral sleeves; none of these had progressed and none were revised. About 3.7% of tibial sleeves subsided more than 1 mm compared with the immediate postoperative X-ray but all stabilized and none were revised.

Conclusion

Use of a metaphyseal sleeve in revision TKA is associated with excellent survivorship and radiographic outcome in the medium to long term.

Highlighting the Roles of Anemia and Aspirin in Predicting Ninety-Day Readmission Following Aseptic Revision Total Joint Arthroplasty

14-10-2019 – William T. Li, Mitchell R. Klement, Carol Foltz, Andrew Sinensky, Hamidreza Yazdi, Javad Parvizi

Journal Article

Background

Revision total joint arthroplasties (TJAs) are associated with an increased rate of complications. To date, it is unclear what drives readmission after aseptic revision arthroplasty and what measures can be taken to possibly avoid them. The purpose of this study is to (1) determine the reasons for readmission after aseptic revision TJA and (2) identify patient-specific or postoperative risk factors through a multivariate analysis.

Methods

A retrospective study examined 1503 cases of aseptic revision TJA between 2009 and 2016 at an urban tertiary care hospital. Eighty-seven cases (5.8%) of readmission within 90 days of index surgery were identified. Bivariate and multivariate analyses were performed to assess independent risk factors for readmission.

Results

The reasons for readmission were infection (38%), wound complications (22%), and dislocation/instability of the prosthetic joint (13%). Only preoperative anemia was associated with an increased odds ratio (OR) of readmission (OR 1.82, 95% confidence interval CI 1.126-2.970, P = .015), whereas postoperative venous thromboembolism prophylaxis with aspirin (OR 0.58, 90% CI 0.340-0.974, P = .039) and discharge to an inpatient rehab facility (OR 0.22, 95% CI 0.051-0.950, P = .042) were associated with significantly lower odds of readmission.

Conclusion

Based on this single institutional study, addressing preoperative anemia and considering the implementation of aspirin for venous thromboembolism prophylaxis may be 2 targets to potentially reduce readmission after aseptic revision TJA.

High Incidence of Intraoperative Fractures With a Specific Cemented Stem Following Intracapsular Displaced Hip Fracture

09-10-2019 – Melissa Laflamme, Michèle Angers, Jessica Vachon, Veronica Pomerleau, Annie Arteau

Journal Article

Background

To reduce costs of orthopedic implants, the government decided to standardize implants used across different specialties in a group of hospitals located in the same geographic area. The usual cemented stem used in the context of intracapsular displaced geriatric hip fractures was replaced by another stem. Abnormal intraoperative calcar and trochanteric fractures were noted. The purpose of this study is to determine the incidence of intraoperative periprosthetic fractures following an intracapsular displaced hip fracture treated with this specific cemented stem compared to the previous implant.

Methods

This is a retrospective cohort study comparing an historic cohort of hip fractures treated with the Omni
Fit EON (Stryker, Kalamazoo, MI) cemented stem with a new cohort of patients who received the Corail (De
Puy Synthes, Warsaw, IN) cemented stem. Four orthopedic surgeons reviewed operative reports and postoperative radiographs.

Results

The treatment group included 348 patients who received the Corail stem. The control group included 77 patients. The 2 groups had similar baseline characteristics (P > .05) except for the presence of dementia. Incidence of intraoperative calcar or greater trochanteric fracture was 15.5% for the Corail group and 2.7% for the control group (P < .05). No patient-related factors or surgeon-related factors were related to a higher number of fractures in the treatment group (P > .05).

Conclusion

The Corail cemented stem presents an abnormal number of iatrogenic intraoperative fractures following displaced femoral neck fracture in our geriatric population. No external factor seems to explain this high number of fractures. Implant design should be questioned.

Level of Evidence

III.

Effects of Chronic Kidney Disease on Hemiarthroplasty Outcomes for Fragility Hip Fracture in Diabetic Patients: A Nationwide Population-Based Observational Study

09-10-2019 – Su-Ju Lin, Tien-Hsing Chen, Liang-Tseng Kuo, Pei-An Yu, Chi-Lung Chen, Wei-Hsiu Hsu

Journal Article

Background

The aim of this study is to compare perioperative outcomes, readmission, and mortality after hemiarthroplasty for hip fractures in diabetic patients with different renal function statuses.

Methods

In this retrospective population-based cohort study, diabetic patients who received primary hemiarthroplasty for hip fracture between January 1997 and December 2013 were identified from the Taiwan National Health Insurance Research Database. Primary outcomes were perioperative outcomes including infection and revision. Secondary outcomes were all-cause readmission and mortality.

Results

A total of 29,535 diabetic patients were included: 8270 patients had chronic kidney disease (CKD group), 1311 patients underwent permanent dialysis (dialysis group), and 19,954 patients did not have CKD (non-CKD group). During a mean follow-up of 4.5 years, these 3 groups had comparable risks of any infection, including superficial and deep infection. Dialysis patients had a significantly higher risk of revision than did CKD and non-CKD patients (subdistribution hazard ratio 1.65, 95% confidence interval 1.16-2.36; subdistribution hazard ratio 1.57, 95% confidence interval 1.10-2.24, respectively). Compared with the non-CKD group, the dialysis group had significantly higher risks of readmission and mortality at all time points, namely 3 months after surgery, 1 year after surgery, and the final follow-up. The CKD group also had higher risks of readmission and mortality than did the non-CKD group at all time points.

Conclusion

CKD is associated with poor outcomes following hemiarthroplasty for fragility hip fracture. CKD patients may have higher risks of surgical complications including revision than non-CKD patients, and they have significantly elevated risks of readmission and mortality.

Differential Use of Narcotics in Total Hip Arthroplasty: Axa0Comparative Matched Analysis Between Osteoarthritis and Femoral Neck Fracture

01-10-2019 – Avinesh Agarwalla, Joseph N. Liu, Anirudh K. Gowd, Nirav H. Amin, Brian C. Werner

Journal Article

Background

The United States is currently in an opioid epidemic as it consumes the majority of narcotic medications. The purpose of this investigation is to identify the incidence and risk factors for prolonged opioid usage following total hip arthroplasty (THA) due to hip fracture (Fx) or osteoarthritis (OA).

Methods

The Pearl
Diver database was reviewed for patients undergoing THA from 2007 through the first quarter of 2017. Following a 3:1 match based on comorbidities and demographics, patients were divided into THA due to Fx (n = 1801) or OA (n = 5403). Preoperative and prolonged postoperative narcotic users were identified. Multivariate logistic regression analysis was performed to identify demographics, comorbidities, or diagnoses as risk factors for prolonged opioid use and preoperative and postoperative opioid use as risk factors for complications.

Results

One thousand seven hundred ninety-four OA patients (33.2%) were prescribed narcotics preoperatively and 1655 patients (30.6%) were using narcotics postoperatively, while 418 Fx patients (23.2%) were prescribed narcotics preoperatively and 499 patients (27.7%) were using narcotics postoperatively. Diagnosis of Fx (odds ratio OR 1.51, 95% confidence interval CI 1.28-1.72, P < .001) and preoperative narcotic use (OR 6.12, 95% CI 5.27-6.82, P < .001) were the most significant risk factors for prolonged postoperative narcotic use. Prolonged postoperative narcotic use was associated with increased infection, dislocation, and revision THA in both Fx and OA groups.

Conclusion

Diagnosis of femoral neck fracture and overall preoperative narcotic use were significant predictors of chronic postoperative opioid use. Patients with significant risk factors for opioid dependence should receive additional consultation and more prudent follow-up with regards to pain management.

Level of Evidence

Therapeutic, Level III.

Assessment of Early Gait Recovery After Anterior Approach Compared to Posterior Approach Total Hip Arthroplasty: A Smartphone Accelerometer–Based Study

21-10-2019 – Nathaniel J. Nelms, Christopher E. Birch, David H. Halsey, Michael Blankstein, Ryan S. McGinnis, Bruce D. Beynnon

Journal Article

Background

The influence of total hip arthroplasty surgical approach on postoperative recovery is not well understood and often debated. This study compares anterior and posterior approach (PA) gait and patient-reported Hip Osteoarthritis Outcome scores (HOOS) in the early phases of recovery.

Methods

A prospective study evaluated 20 control subjects, 35 direct anterior approach (DAA), and 34 PA total hip arthroplasty patients. Subjects were assessed preoperatively and at 1 and 4 months postoperatively with HOOS and smartphone gait assessments of gait speed, step length, cadence, step symmetry, and horizontal and vertical center of mass displacements.

Results

The DAA and PA groups were not different in baseline HOOS or gait characteristics except for less horizontal center of mass displacement in the DAA group. At 1 month postoperatively, the DAA group had significantly faster gait speed at self-selected (P = .02) and fastest possible gait (P = .01) and longer step length at self-selected (P = .047) and fastest gait (P = .003) compared to the PA. At 4 months, there were no differences in DAA and PA gait measures. At 1 month postoperatively there were no significant differences in HOOS, but after 4 months HOOS were significantly higher in the DAA group.

Conclusion

There were minimal differences between the two approaches in the recovery of gait mechanics with some gait parameters particularly gait speed and step length recovery favoring the DAA at 1 month postsurgery in this nonrandomized study.

Prediction of Postoperative Stem Anteversion in Crowe Type II/III Developmental Dysplasia of the Hip on Preoperative Two-Dimensional Computed Tomography

02-11-2019 – Degang Yu, Yiming Zeng, Huiwu Li, Zhenan Zhu, Fengxiang Liu, Yuanqing Mao

Journal Article

Background

Preoperative planning is fundamental for total hip arthroplasty. This study investigated the optimal femoral neck level for measuring femoral anteversion to predict postoperative stem anteversion in developmental dysplasia of the hip and determined the predictive role of average anteversion based on the sagittal 3-point fixation.

Methods

Sixty-two Crowe type II/III dysplastic hips that underwent total hip arthroplasty were retrospectively analyzed. Preoperative and postoperative anteversion was measured via 2-dimensional computed tomography. Anterior and posterior cortex anteversions were measured at 6 levels of the proximal femur. Femoral anteversion at each level was calculated. Average anterior (lesser trochanter) and posterior cortex anteversions (femoral neck) were calculated based on the sagittal 3-point fixation.

Results

From the lesser trochanter to head-neck junction, femoral anteversion decreased gradually from more to less than stem anteversion. For hips with femoral neck height ≥10 mm, femoral anteversion at the 10-mm level above the lesser trochanter proximal base showed no significant difference with stem anteversion, with a good correlation for the single-wedge and an excellent correlation for the double-wedge stem. Average anterior (lesser trochanter proximal base) and posterior cortex anteversions (femoral neck at 10 mm above the lesser trochanter proximal base) showed no significant difference from stem anteversion, with excellent correlations.

Conclusion

For Crowe type II/III hips with femoral neck height ≥10 mm, the 10-mm level above the lesser trochanter proximal base is an optimal choice for measuring femoral anteversion to predict postoperative stem anteversion. The average of anterior cortex anteversion at the lesser trochanter and posterior cortex anteversion at the femoral neck has a predictive role.

Lumbar Spine Fusion Patients See Similar Improvements in Physical Activity Level to Non-Spine Fusion Patients Following Total Hip Arthroplasty

24-09-2019 – Adrian D. Hinman, Maria C.S. Inacio, Heather A. Prentice, Calvin C. Kuo, Monti Khatod, Kern H. Guppy, Elizabeth W. Paxton

Journal Article

Background

The impact of prior lumbar spinal fusion on the change in physical activity level following total hip arthroplasty (THA) has not been thoroughly examined. Therefore, we sought to compare the change in physical activity level following THA for patients with and without a history of lumbar spine fusion.

Methods

Patients who underwent primary elective THA were identified using an integrated healthcare system’s Total Joint Replacement Registry (2010-2013). Prior lumbar spine fusion was identified using the healthcare system’s Spine Registry. Physical activity was self-reported by patients and measured in min/wk. Generalized linear models were used to evaluate the association between prior spine fusion and the change in physical activity from 1 year pre-THA to 1-2 years post-THA.

Results

Of 11,416 THAs, 90 (0.8%) had a history of lumbar spinal fusion. Patients with a prior lumbar fusion had a median physical activity level of 28 min/wk prior to THA compared to 45 min/wk in the patients with no history of lumbar spinal fusion. One year after THA, patients with a history of lumbar spinal fusion reported a median of 120 min/wk of physical activity compared to 150 min/wk for patients without a history of lumbar spinal fusion. The difference in physical activity level change between groups was not statistically significant (estimate = −23.1, 95% confidence interval −62.1 to 15.9, P = .246).

Conclusion

Patients with prior lumbar fusion were found to have lower self-reported physical activity levels than patients without spine fusion both before and after THA surgery. However, both groups saw the same degree of improvement in physical activity level following THA. These findings may help in counseling patients who have had a prior lumbar spine fusion and in setting appropriate expectations prior to THA.

Computer-Assisted Kinematic and Mechanical Axis Total Knee Arthroplasty: A Prospective Randomized Controlled Trial of Bilateral Simultaneous Surgery

09-10-2019 – Peter J. McEwen, Constantine E. Dlaska, Ivana A. Jovanovic, Kenji Doma, Benjamin J. Brandon

Journal Article

Background

Randomized controlled trials of kinematic alignment (KA) and mechanical alignment (MA) in primary total knee arthroplasty (TKA) have to date demonstrated at least equivalence of KA in terms of clinical outcomes. No trial of bilateral TKA has been conducted so patient preference for one technique over the other is unknown.

Methods

Forty-one participants underwent computer-assisted bilateral TKA. The outcome measures were as follows: (1) joint range of motion and functional scores including the KOOS, the KOOS JR, Oxford Knee Score, and the Forgotten Joint Score at a minimum of 2 years; (2) preference and perception of limb symmetry; (3) intraoperative alignment data; (4) release and gap balance data; and (5) postoperative radiographic joint angles.

Results

There were no significant differences with respect to flexion range (P = .970) or functional scores (mean KOOS, P = .941; KOOS JR, P = .685; Oxford Knee Score, P = .578; FJS, P = .542). Significantly more participants who favored one knee preferred their KA TKA (P = .03); however, half of the patients had no preference and the overall numbers were small. Only 3 participants perceived any limb asymmetry (P < .001). More releases were required in the MA group (P = .018). Standing hip-knee-ankle angle means and frequency distributions were similar (P = .097 and P = .097, respectively).

Conclusion

Clinical outcomes were equivalent at 2 years. Significantly more participants preferred their KA joint. Fewer releases were required using a KA technique. Participants were visually insensitive to modest hip-knee-ankle angle asymmetry.

Level of Evidence

Level 1.

Who Will Benefit From Kinematically Aligned Total Knee Arthroplasty? Perspectives on Patient-Reported Outcome Measures

02-11-2019 – Yasuo Niki, Takeo Nagura, Shu Kobayashi, Kazuhiko Udagawa, Kengo Harato

Journal Article

Background

Indications for kinematically aligned total knee arthroplasty (KA-TKA) have remained contentious. This study aimed at exploring preoperative characteristics of patients who were suitable for and benefited from KA-TKA, based on the assessment of patient-reported outcome measures (PROMs).

Methods

Subjects comprised 100 patients undergoing KA-TKA and 100 patients undergoing mechanically aligned (MA)-TKA due to end-stage osteoarthritis. Bone cuts were performed using portable navigation systems according to 3D planning data from computed tomography. At 2 years postoperatively, all 200 patients were assessed for PROMs, including Knee Society Score 2011, pain catastrophizing scale, and pain DETECT score. Multiple regression analysis was performed with activity subscore set as a dependent variable. Principal component analysis was used to evaluate patient satisfaction and function components transformed from the 3 PROMs and to compare these components between KA-TKA and MA-TKA.

Results

Male gender or use of KA technique positively affected advanced activity score, whereas age, body mass index, preoperative pain DETECT score, and preoperative femorotibial angle showed negative effects. In principal component analysis, 38 KA-TKA patients achieved a higher function score, with satisfaction scores comparable to those from MA-TKA. These 38 patients were characterized by a higher percentage of males, younger age, and higher preoperative total activity score.

Conclusion

From the perspective of PROMs, KA-TKA should be favored over MA-TKA for young active males, because these patient groups achieved higher functional activity when undergoing KA-TKA.

A Prospective Randomized Study Comparing Postoperative Pain, Biological Fixation, and Clinical Outcomes Between Two Uncemented Rotating Platform Tibial Tray Designs

21-10-2019 – Paul Hegarty, Andrew Walls, Seamus O’Brien, Barbara Gamble, Laurence Cusick, David E. Beverland

Journal Article

Background

With the demand for arthroplasty increasing worldwide year on year, there is a drive to improve prosthesis longevity. Biological fixation from cementless implants has been one method of trying to achieve this. We hypothesized that the addition of a hydroxyapatite (HA) coating and 4 pegs to a porous-coated tibial tray would provide a reduction in time to implant osseointegration, allowing for normal physiological stress transfer, thus improving early postoperative pain and rehabilitation as well as the elimination of radiolucent lines (RLLs).

Methods

A prospective, randomized controlled single-blinded study was undertaken, comparing postoperative pain, radiographic evidence of biological fixation, and clinical outcomes between patients undergoing primary total knee arthroplasty with either LCS Complete POROCOAT (porous coating only) or LCS Complete DUOFIX (porous coating plus HA and pegs) knee systems (De
Puy Synthes, Warsaw, IN). In total, 197 patients (205 knees) were recruited into the study between November 2006 and November 2008 and have been followed for up to 10 years.

Results

There were no clinically significant differences in pain or patient-reported outcome measures when comparing the 2 designs but the tibial tray with pegs and HA showed fewer RLLs at all time points. There was no correlation between RLLs and pain and no instances of loosening or osteolysis in either group. There was 1 revision for infection in the porous coating only group.

Conclusion

The tray design with HA and additional fixation pegs did not confer any benefit in terms of reduced early postoperative pain or improved patient-reported outcomes, although it did result in significantly fewer RLLs. Both implants demonstrated excellent survivorship. With a cementless porous-coated tibial component, nonprogressive RLLs should be considered normal.

A Single Surgeon Series Comparing the Outcomes of a Cruciate Retaining and Medially Stabilized Total Knee Arthroplasty Using Kinematic Alignment Principles

16-10-2019 – Sofie R. French, Selin Munir, Roger Brighton

Journal Article

Background

Total knee arthroplasty (TKA) designs are developed to optimize kinematics and improve patient satisfaction. The cruciate retaining (CR) and medially stabilized (MS) TKA designs have reported good mid-term follow-up outcomes. However, reasons for consistently high rates of patient dissatisfaction following a TKA remain poorly understood. To further investigate this, we compared the short-term functional outcomes and quality of life, using patient-reported outcome measures (PROMs) and range of motion (ROM), between a CR and MS TKA.

Methods

A prospective comparison was made between 2 groups (44 CR-TKAs vs 46 MS-TKAs). The Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS-12, KOOS-Short form, KOOS-Joint Replacement, Oxford Knee Score, Western Ontario and Mc
Master Universities Osteoarthritis Index, UCLA Activity Scale, and Euro
Quality of life – 5 Dimension were completed preoperatively and 1 year postoperatively. The Forgotten Joint Score (FJS) and Visual Analogue Scale-Satisfaction were completed at 1 year postoperatively. ROM was collected preoperatively and 1 year postoperatively.

Results

Patients who underwent an MS-TKA scored significantly better than the CR-TKA on the FJS (MS = 79.87, CR = 63.8, P = .005), the KOOS-12 Quality of Life subscale (MS = 82.8, CR = 74.4, P = .43), and the KOOS Quality of Life subscale (MS = 82.8, CR = 74.6, P = .44). There was no difference between the groups in all assessed PROMs or ROM, preoperatively and 1 year postoperatively.

Conclusion

Patients who underwent the MS-TKA scored significantly better on the FJS and the quality of life subscale of the KOOS and KOOS-12 than those who underwent a CR-TKA. All other assessed PROMs and ROM were comparable between the 2 groups and demonstrated that both implants facilitated symptom relief and improved daily function at 1 year postoperatively. These findings suggest that at short-term follow-up, the MS device is more likely to allow a patient to “forget” that a joint has been replaced and restore their quality of life. Long-term assessment of MS-TKA design outcomes in larger cohorts is recommended.

A Nationwide Analysis on the Impact of Schizophrenia Following Primary Total Knee Arthroplasty: A Matched-Control Analysis of 49,176 Medicare Patients

13-11-2019 – Rushabh M. Vakharia, Karim G. Sabeh, Nipun Sodhi, Michael A. Mont, Martin W. Roche, Victor H. Hernandez

Journal Article

Background

The influence of schizophrenia on total knee arthroplasty (TKA) is limited in the literature. Therefore, the purpose of this study was to investigate whether patients with schizophrenia undergoing primary TKA have (1) longer in-hospital length of stay (LOS); (2) higher readmission rates; (3) higher medical complications; (4) higher implant-related complications; and (5) higher costs of care compared to controls.

Methods

Patients with schizophrenia undergoing primary TKA were identified within the Medicare claims database. The study group was randomly matched in a 1:5 ratio to controls according to age, sex, and medical comorbidities. The query yielded 49,176 patients with (n = 8,196) and without (n = 40,980) schizophrenia undergoing primary TKA. Primary outcomes analyzed included in-hospital LOS, 90-day readmission rates, 90-day medical complications, 2-year implant-related complications, in addition to day of surgery and 90-day costs of care. A P-value less than .01 was considered statistically significant.

Results

Schizophrenia patients had longer in-hospital LOS (3.73 days vs 3.22 days, P < .0001) and had higher incidence and odds ratios (ORs) of readmission rates (18.26 vs 12.07%; OR: 1.58, P < .0001) compared to controls. Schizophrenia patients had higher incidence and odds of medical (3.23 vs 1.10%; OR: 2.99, P < .0001) and implant-related complications (5.92 vs 3.59%; OR: 1.68, P < .0001) and incurred significantly higher day of surgery ($13,300.58 vs $11,681.77, P < .0001) and 90-day costs of care ($18,222.18 vs $14,845.64, P < .0001).

Conclusion

This study demonstrates that patients with schizophrenia have longer in-hospital LOS, higher readmission rates, higher complications, and increased costs of care after primary TKA.

Use of National Joint Registries to Evaluate a New Knee Arthroplasty Design

21-10-2019 – Edward M. Vasarhelyi, Stephen M. Petis

Journal Article

Background

The introduction of new technology in joint replacement surgery requires close monitoring to identify early successes and failures. This monitoring can be effectively performed through the analysis of registry data and radiostereometric analysis studies. This study examined the revision rates of a contemporary knee system for total knee arthroplasty (TKA) using National Joint Replacement Registries.

Methods

A review of the literature was performed to identify comparative studies and registry databases reporting the revision rates of a specific contemporary knee design between 2013 and 2018. The total number of TKA cases performed using this implant was recorded. The latest follow-up or duration of monitoring through a registry database was used to report implant survivorship.

Results

There were 4 registry databases and 1 comparative study reporting the revision rates of the contemporary knee system. A total of 41,483 cases were identified with a follow-up range of 1.5-5.0 years. The all-cause revision rate ranged from 0.7% to 2.5% at latest follow-up. This was comparable to all-cause revision rates of other knee systems reported in the registries, ranging from 0.8% to 5.6% over similar follow-up periods.

Conclusions

Evaluation of data from multiple national joint registries demonstrated the revision rate for this contemporary knee system to be comparable to other TKA systems at latest follow-up. None of the registries have identified any concerning rates of revision compared to other devices at this length of follow-up. National Joint Registries are an important resource in evaluating the short-term, mid-term, and long-term results of new implant designs introduced to the market.

The Use of Cementless Components Does Not Significantly Increase Procedural Costs in Total Knee Arthroplasty

31-10-2019 – Michael Yayac, Samantha Harrer, William J. Hozack, Javad Parvizi, P. Maxwell Courtney

Journal Article

Background

Modern cementless total knee arthroplasty (TKA) designs have shown promising early clinical success; however, concerns exist regarding the higher cost of the cementless implants. The purpose of this study is to evaluate the total facility cost of cementless vs traditional cemented TKA along with the effect of cementless fixation on short-term outcomes.

Methods

We reviewed a consecutive series of patients between 2015 and 2017 who underwent either cementless or cemented primary TKA. Itemized facility costs were calculated for every procedure using a time-driven activity-based costing algorithm. Controlling for demographic variables and medical comorbidities, we performed a multivariate analysis to identify independent risk factors for facility costs following TKA. Short-term outcome metrics including complications, readmissions, and patient-reported outcomes were compared between groups.

Results

Among the 2426 primary TKA patients in this study, 119 (4.91%) were performed using cementless implants. When compared to cemented TKA, cementless TKA patients had higher implant costs ($3047.80 vs $2808.73, P < .0001), but lower supply costs ($639.49 vs $815.57, P < .0001) and lower operating room personnel costs ($982.01 vs $1238.26, P < .0001). When controlling for confounding variables, cementless fixation did not have a significant effect on total facility cost or outcomes.

Conclusion

In conclusion, the use of cementless TKA implants did not significantly increase total procedural costs when compared to traditional cemented TKA components at our institution. Our data suggest that the increased cost of a cementless implant is recouped through savings in cost of cement and supplies, as well as shorter operative times. The authors encourage investigators at other institutions to use the authors methodology to evaluate (preferably in a prospective manner) whether the findings from this study can be corroborated.

One-Stage Sequential Bilateral Total Knee Arthroplasty: An Effective Treatment for Advanced Bilateral Knee Osteoarthritis Providing High Patient Satisfaction

23-10-2019 – Sven E. Putnis, Antonio Klasan, Joachim D. Redgment, Matthew S. Daniel, David A. Parker, Myles R.J. Coolican

Journal Article

Background

The mortality and risks of bilateral total knee arthroplasty (BTKA) have been reported to be far greater than in unilateral total knee arthroplasty (UTKA). This study aimed to determine whether this remains the case using contemporary anesthetic and surgical techniques for one-stage single anesthetic sequential BTKA.

Methods

Two cohorts of 394 patients were created by propensity matching for gender, age, body mass index, American Society of Anesthesiologists grade, and Veterans Rand-12 health survey scores. Primary outcome was morbidity and mortality, with satisfaction measures using patient-reported outcome measures.

Results

The mortality rate was low with one case after BTKA. Major complications were also low; however, a pulmonary embolism rate of 2% in BTKA patients was significantly higher than 0.3% after UTKA (P < .05), and associated with an American Society of Anesthesiologists grade ≥3. The rate of minor complications between the 2 cohorts was comparable (P = .95). Blood transfusions were uncommon and not significantly different between cohorts (2.5% vs 1.3%, P = .3). BTKA patients stayed in hospital a mean 1.3 days longer with greater rehabilitation requirements. At final follow-up, patient satisfaction was high with all patient-reported outcome measures significantly improved and comparable between cohorts.

Conclusion

BTKA is safe and effective in the majority of patients. Transfusion rates were far lower than historically reported and major complications were rare after both UTKA and BTKA. A significant increase in the rate of pulmonary embolism after BTKA was observed, especially in high risk patients. At minimum 1-year postoperatively, cohorts had the same significant clinical improvement and high level of satisfaction.

Intravenous Dexamethasone Injection Reduces Pain From 12 to 21 Hours After Total Knee Arthroplasty: A Double-Blind, Randomized, Placebo-Controlled Trial

08-10-2019 – Nattapol Tammachote, Supakit Kanitnate

Journal Article

Background

Pain after total knee arthroplasty (TKA) affects postoperative recovery and patient satisfaction. The analgesic benefits of corticosteroids have not been well studied. We, therefore, investigated the analgesic effects of intravenous (IV) dexamethasone (DEX) in patients undergoing a TKA.

Methods

This was a randomized, double-blind, placebo-controlled trial of 0.15 mg/kg of IV DEX vs saline placebo in unilateral TKA. Fifty patients/arm were recruited. Primary outcomes were pain level, determined by a visual analog scale, and the amount of morphine consumption (mg) ≤48 hours post-TKA. Secondary outcomes were rates of nausea and vomiting, C-reactive protein concentrations, and functional outcomes.

Results

The DEX group had a significantly lower mean visual analog scale score both at rest and during motion at 12, 15, 18, and 21 hours (P < .05). At 21 hours, the mean difference (Δ) in pain at rest was −11 points (95% confidence interval CI, −21 to −2 points; P = .02) while the mean difference in pain during motion was −15 points (95% CI, −25 to −5 points; P = .004). The DEX group also had lower rates of nausea and vomiting: 29/50 (58%) vs 42/50 (84%) (P = .008) and lower mean C-reactive protein level: 89 vs 167, Δ = −78 mg/L (95% CI, −100 to −58 mg/L, P < .0001). There were no significant differences in mean morphine consumption by 48 hours, modified Western Ontario and Mc
Master University Osteoarthritis Index scores, and range of motion of the knee at 3-month follow-up (P > .05).

Conclusion

IV DEX relieves postoperative pain between 12 to 21 hours after TKA and may be a useful adjunct for controlling pain in patients undergoing TKA.

Influence of Narrow Femoral Implants on Intraoperative Soft Tissue Balance in Posterior-Stabilized Total Knee Arthroplasty

13-10-2019 – Kazunari Ishida, Nao Shibanuma, Hiroshi Sasaki, Koji Takayama, Ryosuke Kuroda, Tomoyuki Matsumoto

Journal Article

Background

Narrow femoral implants were developed to improve fit and prevent overhang in primary total knee arthroplasty (TKA). We compared intraoperative soft tissue balance between standard and narrow implants in posterior-stabilized (PS) TKA.

Methods

We enrolled 30 consecutive patients with varus osteoarthritis undergoing PS TKA using an image-free navigation system. Standard and narrow femoral trial implants were inserted, and their soft tissue balance was measured. Subgroup analysis, based on the actual implanted femoral implant, was performed to assess the influence of narrow implants on soft tissue balance.

Results

Narrow trial group had significantly larger joint component gaps than standard trial group at all measured flexion angles, except at 60° (P < .05). For the standard implant cohort, narrow trial group had significantly larger joint component gaps than standard trial group at 30°, 120°, and 135° flexion (P < .05). For the narrow implant cohort, narrow trial group had significantly larger joint component gaps than standard trial group at all measured flexion angles, except at 0° and 60° (P < .05). Narrow trial group had significantly larger varus ligament balance than standard trial group at 45° and 60° flexion (P < .05). The varus angles for standard implants were comparable between groups; however, narrow trial group had significantly larger varus angles for narrow implants than standard trial group at 45°, 60°, and 120° flexion (P < .05).

Conclusion

The medial-lateral dimension and volume of the femoral component may influence intraoperative soft tissue balance in PS TKA. The effects may be greater when narrow implants are selected to avoid component overhang.

Efficacy and Safety of Functional Medial Ligament Balancing With Stepwise Multiple Needle Puncturing in Varus Total Knee Arthroplasty

08-10-2019 – Fong Teck Siong, Tae Woo Kim, Seong Chan Kim, Eui Soo Lee, Mohd Shahrul Azuan Jaffar, Yong Seuk Lee

Journal Article

Background

The aims of this study were to (1) describe our functional stepwise multiple needle puncturing (MNP) technique as the final step in medial ligament balancing during total knee arthroplasty (TKA) and (2) evaluate whether this technique can provide sufficient medial release with safety.

Methods

A total of 137 patients with 212 consecutive knees who underwent TKAs with or without functional stepwise MNP of superficial medial collateral ligament was recruited in this prospective cohort. Eighty-one patients with 129 knees who performed serial stress radiographs were enrolled in the final assessment. Superficial medial collateral ligament was punctured selectively (anteriorly or posteriorly or both) and sequentially depending on the site and degree of tightness. Mediolateral stability was assessed using serial stress radiographs and comparison was performed between the MNP and the non-MNP groups at postoperative 6 months and 1 year. Clinical outcomes were also evaluated between 2 groups.

Results

Fifty-five TKAs required additional stepwise MNP (anterior needling 19, posterior needling 3, both anterior and posterior needling 33). Preoperative hip-knee-ankle angle and the difference in varus-valgus stress angle showed significant difference between the MNP and the non-MNP groups, respectively (P = .009, P = .037). However, there was no significant difference when comparing the varus-valgus stress angle between the MNP and the non-MNP groups during serial assessment. Clinical outcomes including range of motion also showed no significant differences between the 2 groups.

Conclusion

Functional medial ligament balancing with stepwise MNP can provide sufficient medial release with safety in TKA with varus aligned knee without clinical deterioration or complication such as instability.

Level of Evidence

Level II, Prospective cohort study.

Patterns of Weight Change and Their Effects on Clinical Outcomes Following Total Knee Arthroplasty in an Asian Population

30-09-2019 – Tanzib Razzaki, Wai-Keong Mak, Hamid Rahmatullah Bin Abd Razak, Hwee-Chye Andrew Tan

Journal Article

Background

This prospective cohort study was designed to evaluate weight change patterns and their effects on clinical outcomes following total knee arthroplasty (TKA) in the Asian population. We hypothesized that Asian patients will have a different pattern of weight change following TKA compared to Western patients and that weight loss following TKA will be associated with better clinical outcomes.

Methods

A cohort of consecutive patients who underwent TKA from 2004 to 2015 was included. All patients received a conventional posterior-stabilized TKA implant and underwent a standard perioperative care pathway. Assessments were done preoperatively, at 6 months, and 2 years after surgery. The range of motion, Knee Society Score, Oxford Knee Score, and the Short-Form 36 questionnaire were used to assess outcomes. Height and weight of patients were recorded for body mass index (BMI) calculation. Patterns of weight loss following TKA in this cohort were charted. Clinical outcomes were then analyzed against the change in BMI.

Results

A total of 602 patients (602 knees) were reviewed. Mean age was 66.39 ± 7.27 years. Mean BMI was 27.75 ± 4.51 kg/m2. Overall, 63.12% of all our patients gained weight following TKA. Moreover, weight loss did not influence patients’ odds for better clinical outcomes. Furthermore, patients who were in the preoperative BMI category of obese class I were more likely to gain weight as compared to those in the normal category (odds ratio 0.35, 95% confidence interval 0.2-0.61, P < .001). Moreover, older people were more likely to gain more weight compared to younger people. We also showed that the mean 2-year Knee Society Knee Score was significantly higher in the patients who gained weight while the patients who lost weight had the highest mean 2-year Oxford Knee Score and the lowest mean 2-year Knee Society Function Score.

Conclusion

Asians tend to gain weight following TKA. However, this weight change following TKA does not affect clinical outcomes, which remain good across all BMI groups.

Level of Evidence

Therapeutic Level III.

Complication Rates in Total Knee Arthroplasty Performed for Osteoarthritis and Post-Traumatic Arthritis: A Comparison Study

14-10-2019 – Bryan S. Brockman, Jeremiah J. Maupin, Samuel F. Thompson, Kimberly M. Hollabaugh, Rishi Thakral

Journal Article

Background

The number of total knee arthroplasty (TKA) procedures performed in the United States has been increasing. Increased complication rates have been demonstrated in patients with post-traumatic arthritis (PTA) undergoing TKA. However, there remains limited data directly comparing outcomes of TKA performed for osteoarthritis (OA) and PTA.

Methods

The National Inpatient Sample was utilized to identify patients undergoing elective TKA between 2006 and 2015 for OA and PTA. The prevalence of preoperative comorbidities and the incidence of postoperative complications including superficial wound infection, deep joint infection, acute deep venous thrombosis, and pulmonary embolus were analyzed.

Results

Between 2006 and 2015, the National Inpatient Sample database accounted for 1,301,394 patients diagnosed with either PTA (14,206) or OA (1,287,188) undergoing TKA. The incidence of superficial wound infection, deep joint infection, and acute deep venous thrombosis was found to occur at a higher rate in patients with a diagnosis of PTA compared to OA. The incidence of pulmonary embolus was not found to be statistically different between the 2 groups. Patients with PTA had a higher prevalence of drug and alcohol abuse, psychosis, and liver disease, whereas patients with OA had a higher prevalence of obesity, diabetes, heart disease, and lung disease.

Conclusion

This study demonstrates an increased risk of complications in patients undergoing TKA for PTA compared to OA. Surgeons can use this information to help aid in counseling patients preoperatively. Furthermore, these data provide objective evidence that could have implications with regards to establishing bundled payment reimbursement in this patient population.

No Difference in Force Required for Intraprosthetic Dislocation of Mixed Manufacturer vs Same Manufacturer Dual Mobility Articulations

28-10-2019 – Leonard T. Buller, Lisa Torres, Elexis C. Baral, Timothy M. Wright, Michael P. Ast

Journal Article

Background

To avoid the morbidity of removing well-fixed implants during revision surgery, the off-label practice of mixing femoral heads with dual mobility (DM) polyethylene liners from different manufacturers is commonly performed. The resistance to intraprosthetic dislocation, when the inner prosthetic head disengages from the polyethylene bearing, between mixed and same manufacturer constructs remains unknown.

Methods

Between January 2010 and July 2018, 168 DM liners were retrieved. Specimens were excluded for catastrophic wear (n = 14), previously levered-out (n = 17), and cases in legal proceedings (n = 8). Using a validated setup, 129 specimens were uniaxially loaded 100 mm from the femoral head until lever-out failure of the head from the liner. The difference in maximum lever-out force (LOF) was compared for same and mixed manufacturer retrievals (Student t-test). Multivariable regression analysis evaluated the influence of potential confounders (length of implantation, head size, head material, presence of skirt) on LOF.

Results

Ninety-seven same and 32 mixed manufacturer DM constructs were tested. The average LOF for same (272.6 ± 68.7 N) and mixed (299.2 ± 89.0 N) manufacturer specimens was not significantly different (P = .08). An inner head size of 22.2 mm was associated with 184.4-N increase in LOF (P < .001), the presence of a skirt was associated with 63.8-N increase in maximum LOF, and head material (ceramic vs metal) did not influence LOF.

Conclusion

We found no difference in the force required to lever-out same and mixed manufacturer inner heads from DM liners, suggesting that mixing manufacturers when placing DM articulations on well-fixed femoral stems should not increase the risk of intraprosthetic instability.

Perception of a Natural Joint After Total Knee Arthroplasty

21-10-2019 – David Eichler, Yann Beaulieu, Janie Barry, Vincent Massé, Pascal-André Vendittoli

Journal Article

Background

Assessing patients’ functional outcomes following total knee arthroplasty (TKA) with traditional scoring systems is limited by their ceiling effects. Patient’s Joint Perception (PJP) question of the reconstructed joint is also of significant interest. Forgotten Joint Score (FJS) was created as a more discriminating option. The actual score constituting a “forgotten joint” has not yet been defined. The primary objective of this study is to compare the PJP and the FJS in TKA patients to determine the FJS score that corresponds to the patient’s perception of a natural joint.

Methods

One hundred TKAs were assessed at a mean of 40.6 months of follow-up using the PJP question, FJS, and Western Ontario and Mc
Master Universities Osteoarthritis Index (WOMAC). Correlation between the 3 scores and their ceiling effects were analyzed.

Results

With PJP question, 39% of the patients perceived a natural joint (FJS: 92.9; 95% confidence interval CI, 89.4-96.4), 12% an artificial joint with no restriction (FJS: 79.5; 95% CI, 65.7-93.3), 36% an artificial joint with minor restrictions (FJS: 70.0; 95% CI, 63.2-76.9), and 13% had major restrictions (FJS: 47.3; 95% CI. 32.8-61.7). PJP has a high correlation with FJS and WOMAC (Spearman’s rho, −0.705 and −0.680, respectively). FJS and WOMAC had a significant ceiling effect with both reaching the best possible score in >15%.

Conclusion

Patients perceiving their TKA as a natural knee based on PJP have a FJS ≥89. PJP has a good correlation with FJS and may be a shorter, simple, and acceptable alternative.

The Impact of Coronal Alignment on Revision in Medial Fixed-Bearing Unicompartmental Knee Arthroplasty

02-11-2019 – Sean E. Slaven, John P. Cody, Robert A. Sershon, Henry Ho, Robert H. Hopper, Kevin B. Fricka

Journal Article

Background

To better define the optimal alignment target for medial fixed-bearing unicompartmental knee arthroplasty (UKA), this study compares the postoperative mechanical alignment of well-functioning UKAs against 2 groups of failed UKAs, including revisions for progression of lateral compartment osteoarthritis (“Progression”) and revisions for aseptic loosening or subsidence (“Loosening”).

Methods

From our prospective institutional database of 3351 medial fixed-bearing UKAs performed since 2000, we identified 37 UKAs revised for Progression and 61 UKAs revised for Loosening. Each of these revision cohorts was matched based on age at surgery, gender, body mass index, and postoperative range of motion with unrevised UKAs that had at least 10 years of follow-up and a Knee Society Score of 70 or greater without subtracting points for alignment (“Success” groups). Postoperative alignment was quantified by the hip-knee-ankle (HKA) angle measured on long-leg alignment radiographs.

Results

The mean HKA angle at 4-month follow-up for the Progression group was 0.3° ± 3.6° of valgus compared to 4.4° ± 2.6° of varus for the matched Success group (P < 0.001). For the Loosening group, the mean HKA angle was 6.1° ± 3.1° of varus versus 4.0° ± 2.7° of varus for the matched Success group (P < 0.001).

Conclusions

Patients with well-functioning UKAs at 10 years exhibited mild varus mechanical alignment of approximately 4°, whereas patients revised for progression of osteoarthritis averaged more valgus and those revised for loosening or subsidence averaged more varus. The optimal mechanical alignment for medial fixed-bearing UKA survival with contemporary polyethylene is likely slight varus.

Adherence to the American Academy of Orthopaedic Surgeons Clinical Practice Guidelines for Nonoperative Management of Knee Osteoarthritis

30-09-2019 – Karthik P. Meiyappan, Mark P. Cote, Kevin J. Bozic, Mohamad J. Halawi

Journal Article

Background

The American Academy of Orthopaedic Surgeons (AAOS) has published evidence-based Clinical Practice Guidelines (CPGs) for the nonarthroplasty management of knee osteoarthritis (OA). The purpose of this study is to determine how closely our orthopedic providers adhered to the recommendations included in those CPGs.

Methods

We retrospectively reviewed 1096 consecutive ambulatory visits with primary diagnosis of knee OA at a single center. Demographic, radiographic, and treatment information was collected. The primary outcome was the frequency of agreement between our treatment recommendations and the AAOS CPGs. A secondary outcome was the associated costs of care.

Results

The total number of interventions generated during the visits was 1955. Adherence to the AAOS guidelines was 65% (362/557), 60% (226/377), and 40% (413/1021) in new/never treated, new/previously treated, and return patients, respectively. Intra-articular injection with either corticosteroids or hyaluronic acid was the most common intervention (32%) followed by physical therapy (29%). As the severity of OA increased, adherence to the AAOS guidelines decreased (61%, 60%, 54%, and 49% for Kellgren-Lawrence grades I through IV, respectively). The estimated annual costs associated with our treatment recommendations were $2,403,543.18, of which $1,206,757.8 (50.2%) was supported by evidence. The most expensive treatment intervention was intra-articular hyaluronic acid injection, which carried a strong evidence against its use.

Conclusion

Adherence to the recommendations contained within the AAOS CPGs was modest regardless of the Kellgren-Lawrence grade or history of treatment. Given the size of the affected patient population, there is a need for uniformly accepted guidelines to clarify the role and timing of the different treatment interventions. CPGs should be combined with education, patient engagement, and shared decision-making to minimize variation in treatment patterns, improve patient outcomes, and lower overall costs of care.

Long-Term Sustainability of a Quality Initiative Program on Transfusion Rates in Total Joint Arthroplasty: A Follow-Up Study

25-09-2019 – Nicholas J. Bolz, Bradley J. Zarling, David C. Markel

Journal Article

Background

There are significant variations in transfusion rates among institutions performing total joint arthroplasty. We previously demonstrated that implementation of an educational program to increase awareness of the American Association of Blood Banks’ transfusion guidelines led to an immediate decrease in transfusion rates at our facilities. It remained unclear how this initiative would endure over time. We report the long-term success and sustainability of this quality program.

Methods

We reviewed the Michigan Arthroplasty Collaborative Quality Initiative data from 2012 through 2017 of all patients undergoing primary hip and knee arthroplasty at our institutions for preoperative and postoperative hemoglobin level, transfusion status, and number of units transfused and transfusions outside of protocol to identify changes surrounding our blood transfusion educational initiative. We calculated the transfusions prevented and cost implications over the course of the study.

Results

We identified 6645 primary hip and knee arthroplasty patients. There was a significant decrease in transfusion rate and overall transfusions in each group when compared to pre-education values. Subgroup analysis of TKA and THA independently showed significant decreases in both transfusion rate and overall transfusions. Over the final 3 years of the study, only 2 patients were transfused outside of the American Association of Blood Banks protocol. We estimate prevention of 519 transfusions over the study period.

Conclusion

Application of this quality initiative was an effective means of identifying opportunities for quality improvement. The program was easily initiated, had significant early impact, and has been shown to be sustainable.

Patient-Reported Outcome Measures are not a Valid Proxy for Patient Satisfaction in Total Joint Arthroplasty

16-10-2019 – Mohamad J. Halawi, Walter Jongbloed, Samuel Baron, Lawrence Savoy, Mark P. Cote, Jay R. Lieberman

Journal Article

Background

Patient-reported outcome measures (PROMs) are increasingly used as quality benchmarks in total joint arthroplasty. The objective of this study is to investigate whether PROMs correlate with patient satisfaction, which is arguably the most important and desired outcome.

Methods

Our institutional joint database was queried for patients who underwent primary, elective, unilateral total joint arthroplasty. Eligible patients were asked to complete a satisfaction survey at final follow-up. Correlation coefficients (R) were calculated to quantify the relationship between patient satisfaction and prospectively collected PROMs. We explored a wide range of PROMs including Western Ontario and Mc
Master Universities Osteoarthritis Index (WOMAC), Short Form-12, Oxford Hip Score, Knee Society Clinical Rating Score (KSCRS), Single Assessment Numerical Evaluation, and University of California Los Angeles activity level rating.

Results

In general, there was only weak to moderate correlation between patient satisfaction and PROMs. Querying the absolute postoperative scores had higher correlation with patient satisfaction compared to either preoperative scores or net changes in scores. The correlation was higher with disease-specific PROMs (WOMAC, Oxford Hip Score, KSCRS) compared to general health (Short Form-12), activity level (University of California Los Angeles activity level rating), or perception of normalcy (Single Assessment Numerical Evaluation). Within disease-specific PROMs, the pain domain consistently carried the highest correlation with patient satisfaction (WOMAC pain subscale, R = 0.45, P < .001; KSCRS pain subscale, R = 0.49, P < .001).

Conclusion

There is only weak to moderate correlation between PROMs and patient satisfaction. PROMs alone are not the optimal way to evaluate patient satisfaction. We recommend directly querying patients about satisfaction and using shorter PROMs, particularly disease-specific PROMs that assess pain perception to better gauge patient satisfaction.

Acetabular Anatomical Parameters in Patients With Idiopathic Osteonecrosis of the Femoral Head

11-11-2019 – Junfeng Zeng, Yi Zeng, Yuangang Wu, Yuan Liu, Huiqi Xie, Bin Shen

Journal Article

Background

Osteonecrosis of the femoral head (ONFH) is an increasing worldwide health problem. However, about 30% of the patients are diagnosed with idiopathic ONFH, which means no underlying etiology is identified. We hypothesized that acetabular anatomical abnormalities might be related to idiopathic ONFH.

Methods

This retrospective, 1:2 matched, case-control study included 101 patients (136 hips) with idiopathic ONFH and 202 control subjects (404 hips) matched for age, gender, and body mass index who had no apparent radiographic hip pathologies. The anteroposterior pelvic X-rays of the patients and control subjects were used to measure the anatomical parameters including the center-edge angle, the sharp angle, the acetabular depth ratio (ADR), and the acetabular head index (AHI).

Results

We found that hips with idiopathic osteonecrosis had less acetabular coverage, lower center-edge angle (28.3° vs 32.3°, P < .001), acetabular depth ratio (298.0 vs 306.4, P = .006), and acetabular head index (82.2 vs 85.8, P < .001), and higher sharp angle (39.7° vs 38.0°, P < .001), compared with the control subjects. The incidence of acetabular dysplasia was also higher in the idiopathic ONFH group than the control group.

Conclusion

Less acetabular coverage was found in hips with idiopathic osteonecrosis than the control subjects. Less acetabular coverage may be associated with the development of ONFH in East Asian population.

Platelet-Rich Plasma-Incorporated Autologous Granular Bone Grafts Improve Outcomes of Post-Traumatic Osteonecrosis of the Femoral Head

08-10-2019 – Hang Xian, Deqing Luo, Lei Wang, Weike Cheng, Wenliang Zhai, Kejian Lian, Dasheng Lin

Journal Article

Background

To investigate the effects of platelet-rich plasma (PRP)-incorporated autologous granular bone grafts for treatment in the precollapse stages (Association of Research Circulation Osseous stage II–III) of posttraumatic osteonecrosis of the femoral head.

Methods

A total of 46 patients were eligible and enrolled in the study. Twenty-four patients were treated with core decompression and PRP-incorporated autologous granular bone grafting (treatment group), and 22 patients were treated with core decompression and autologous granular bone grafting (control group). During a minimum follow-up duration of 36 months, X-ray and computed tomography were used to evaluate the radiological results, and the Harris hip score (HHS) and visual analog scale were chosen to assess the clinical results.

Results

Both the treatment and control groups had a significantly improved HHS (P < .001). The minimum clinically important difference for the HHS was reached in 91.7% of the treatment group and 68.2% of the control group (P < .05). The HHS and visual analog scale in the treatment group were significantly improved than that in the control group at the last follow-up (P < .05). Successful clinical and radiological results were achieved 87.5% and 79.2% in the treatment group compared with 59.1% and 50.0% in the control group (P < .05), respectively. The survival rates based on the requirement for further hip surgery as an endpoint were higher in the treatment group in comparison to those in the control group (P < .05).

Conclusion

PRP-incorporated autologous granular bone grafting is a safe and effective procedure for treatment in the precollapse stages (Association of Research Circulation Osseous stage II–III) of posttraumatic osteonecrosis of the femoral head.

What Factors Predict Patient Dissatisfaction After Contemporary Medial Opening-Wedge High Tibial Osteotomy?

22-10-2019 – Sueen Sohn, In Jun Koh, Man Soo Kim, Byung Min Kang, Yong In

Journal Article

Background

Although current advances in surgical techniques have improved outcomes of the medial opening-wedge high tibial osteotomy (MOWHTO), the factors associated with patient dissatisfaction remain unclear. Thus, the purpose of this study is to identify risk factors for patient dissatisfaction following contemporary MOWHTO.

Methods

We retrospectively reviewed prospectively collected data on 140 consecutive MOWHTO patients using an anatomical locking plate with a minimum follow-up of 2 years. Patient demographics, pain Visual Analogue Scale, Western Ontario and Mc
Master Universities Osteoarthritis Index, Kellgren-Lawrence (K-L) grade, activity level, articular cartilage and meniscal status, hip-knee-ankle angle, change in alignment, and postoperative weight-bearing line ratio were recorded. Patients were categorized using the New Knee Society Score into satisfied (satisfaction score ≥20) or dissatisfied (satisfaction score <20) groups. Patient and surgical factors were compared between the groups by the identified predictors. Multiple logistic regression analysis was used to analyze risk factors, including K-L grade IV medial osteoarthritis (OA), preoperative pain Visual Analogue Scale, total Western Ontario and Mc
Master Universities Osteoarthritis Index score, postoperative hip-knee-ankle angle, change in alignment, and partial meniscectomy.

Results

Of the 140 patients, 24 (17.1%) were dissatisfied with their results. Multiple logistic regression analysis showed that only K-L grade IV medial OA was statistically associated with patient dissatisfaction following MOWHTO (odds ratio 4.911, 95% confidence interval 1.820-13.256, P < .01).

Conclusion

Severe medial OA was an independent risk factor for dissatisfaction following contemporary MOWHTO using a rigid locking plate. Surgeons should take this into consideration when counseling and choosing surgical options in MOWHTO candidates with severe medial OA.

Level of Evidence

Level III.

What Are the Costs of Hip Osteoarthritis in the Year Prior to a Total Hip Arthroplasty?

12-10-2019 – Azeem T. Malik, John H. Alexander, Daniel D. Li, Mengnai Li, Safdar N. Khan, Thomas J. Scharschmidt

Journal Article

Background

The majority of the cost analysis literature on total hip arthroplasties (THAs) has been focused around the perioperative and postoperative period, with preoperative costs being overlooked.

Methods

The Humana Administrative Claims database was used to identify Medicare Advantage (MA) and Commercial beneficiaries undergoing elective primary THAs. Preoperative healthcare resource utilization in the year prior to a THA was grouped into the following categories: office visits, X-rays, magnetic resonance imagings, computed tomography scans, intra-articular steroid and hyaluronic acid injections, physical therapy, and pain medications. Total 1-year costs and per-patient average reimbursements for each category have been reported.

Results

Total 1-year preoperative costs amounted to $21,022,883 (average = $512/patient) and $4,481,401 (average = $764/patient) for MA and Commercial beneficiaries, respectively. The largest proportion of total 1-year costs was accounted for by office visits (35% in Commercial; 41% in MA) followed by pain medications (28% in Commercial; 35% in MA). Conservative treatments (steroid injections, hyaluronic acid injections, physical therapy, and pain medications) alone accounted for 40%-44% of the total 1-year costs prior to a THA. A high healthcare utilization within the last 3 months prior to surgery was noted for opioids and steroid injections.

Conclusion

On average, $500-$800/patient is spent on hip osteoarthritis-related care in the year prior to a THA. Despite their potential risks, opioids and steroid injections are often utilized in the last 3 months prior to surgery.

Zip Codes May Not Be an Adequate Method to Risk Adjust for Socioeconomic Status Following Total Joint Arthroplasty at the Individual Surgeon Level

02-11-2019 – Benjamin H. Dalkin, Luke R. Sampson, Wendy M. Novicoff, James A. Browne

Journal Article

Background

Increasing consumerism in healthcare has included a push toward the ranking of individual surgeons. These rankings rely on the adjustment of patient outcomes based on individual patient risk. Socioeconomic status (SES) has been identified as an important variable impacting patient outcomes following total joint arthroplasty, and patient zip code has been proposed as a proxy. Our study attempts to determine if zip code is an acceptable proxy for SES within a single surgeon’s practice.

Methods

Using public zip code and Geographic Information Systems (GIS) tax map data, we compared the real estate holdings of 244 patients undergoing total joint arthroplasty from an individual hip and knee arthroplasty surgeon’s practice within an academic medical center over a 14-month period. An independent t-test was used to compare GIS data with the average home value within a given zip code. A Pearson correlation coefficient was calculated between GIS values and average home value per zip code.

Results

In a sample of 244 patients, mean home value calculated from GIS data was $335,993 (standard deviation SD $246,549), and $243,663 with zip code data (SD $84,731). The Pearson correlation coefficient was 0.411 (P < .001). There was a significant difference between mean home values calculated from zip code data and GIS data (P < .001). Using zip code estimates would have mischaracterized home value, as defined as greater than or less than 1 SD, in 15% of patients.

Conclusion

Although there was some relationship between zip code and real estate holdings, the correlation is only moderate in strength and a substantial number of outliers were present. Given the sample size at the individual surgeon level, we question whether zip code can be used as a proxy for SES risk adjustment for the purposes of surgeon ranking.

Optimal Length of Stay Following Total Joint Arthroplasty to Reduce Readmission Rates

08-10-2019 – Patricia A. Kirkland, William R. Barfield, Harry A. Demos, Vincent D. Pellegrini, Jacob M. Drew

Journal Article

Background

Length of stay (LOS) following total joint arthroplasty (TJA) continues to decrease. The effects of this trend on readmission risk and total cost are unclear. We hypothesize that optimal LOS following TJA minimizes index hospitalization, early readmission risk, and total cost.

Methods

Retrospective data from the South Carolina Department of Revenue and Fiscal Affairs was reviewed for patients who underwent primary TJA in South Carolina from 2000 to 2015 (n = 172,760). Data for readmissions within 90 days were included. Severity of illness was estimated by Elixhauser score (EH). Index LOS is defined as the surgery and the subsequent hospital stay.

Results

Patients with more significant medical comorbidities (EH ≥ 4) had significantly longer LOS than healthier patients (4.0 vs 3.4 days, P < .001). Independent of EH, readmitted patients had a significantly longer index LOS than those never readmitted (4.3 vs 3.6 days, P < .001). For healthier patients (EH ≤ 3), each additional inpatient day increased readmission risk, while among sicker patients, staying 2 days vs 1 day was protective against readmission risk. Since 2000, the total index cost of TJA has doubled and average cost per inpatient day has tripled, but readmission rates remain essentially unchanged (7.4% to 7.0%).

Conclusion

Increased LOS was associated with increased readmission risk. Patients with greater medical comorbidities stay longer to protect against readmission. Optimal LOS after TJA is highly influenced by the patient’s overall health. Despite a 300% increase in TJA daily cost, readmission rate has changed minimally over the last 15 years.

Corrigendum to ‘Surgical Approaches and Hemiarthroplasty Outcomes for Femoral Neck Fractures: A Meta-Analysis’ The Journal of Arthroplasty 33 (2018) 1617-1627

25-11-2019 – Max P.L. van der Sijp, Danny van Delft, Pieta Krijnen, Arthur H.P. Niggebrugge, Inger B. Schipper

Published Erratum

Comparative Analysis Investigating the Impact of Implant Design on Hospital Length of Stay and Discharge Destination in a Dutch Hospital With an Established Enhanced Recovery Program

17-09-2019 – Geert Meermans, Thibaut Galvain, Richard Wigham, Bronwyn Do Rego, Dafne Schröer

Journal Article

Background

Global demand for total knee arthroplasty (TKA) is increasing, driven by an aging and increasingly overweight patient population, culminating in higher healthcare costs. In the Netherlands, the number of TKA surgeries performed annually increased from 21,000 in 2010 to 29,000 in 2017. This study aimed to assess the impact of implant design on hospital length of stay (LOS), surgery time, and discharge destination (home vs a rehabilitation center) in a Dutch hospital with an established enhanced recovery program and short baseline LOS.

Methods

A retrospective review of consecutive adult patients who underwent primary TKA in a Dutch hospital between 2015 and 2017 using either the comparator device or the control device.

Results

A total of 200 patients were enrolled in the study (100 per group). Patients who received a comparator device had a significantly shorter LOS (adjusted mean 2.76 days; 95% confidence interval CI: 2.45, 3.11) vs the control group (adjusted mean 3.43 days; 95% CI: 3.08, 3.81; P < .01). The proportion of patients discharged to a rehabilitation center, instead of home, was also significantly lower in the comparator device group (adjusted 4.4%; 95% CI: 1.8, 10.7 vs adjusted 11.4%; 95% CI: 6.0, 20.6; P < .05). There was no difference in surgical time between the 2 groups. None of the sensitivity analyses performed affected the original analysis outcome.

Conclusion

This study shows a modest but significant reduction in length of stay and lower rate of discharge to a rehabilitation center in the comparator device group.

Implant-Related Complications Among Patients With Opioid Use Disorder Following Primary Total Hip Arthroplasty: A Matched-Control Analysis of 42,097 Medicare Patients

01-09-2019 – Rushabh M. Vakharia, Karim G. Sabeh, Nipun Sodhi, Qais Naziri, Michael A. Mont, Martin W. Roche

Journal Article

Background

Opioid use disorders (OUD) are a major cause of morbidity and mortality. The authors of this study hypothesize that patients who have an OUD will have greater relative risk of implant-related complications, periprosthetic joint infections (PJIs), readmission rates, and will incur greater costs compared to non-opioid use disorder (NUD) patients following primary total hip arthroplasty (THA).

Methods

OUD patients who underwent a THA between 2005 and 2014 were identified and matched to controls in a 1:5 ratio according to age, sex, a comorbidity index, and various medical comorbidities yielding 42,097 patients equally distributed in both cohorts. Pearson’s chi-square analyses were used to compare patient demographics. Relative risk (RR) was used to analyze and compare risk of 2-year implant-related complications, 90-day PJIs, and 90-day readmission rates. Welch’s t-tests were used to compare day of surgery and 90-day episode-of-care costs between the cohorts. A P value less than .006 was considered statistically significant.

Results

OUD patients had higher incidences and risks of implant-related complications (11.99% vs 6.68%; RR, 1.74; P < .001), developing PJIs within 90 days (2.38% vs 1.81%; RR, 1.32; P = .001), and 90-day readmissions (21.49% vs 17.35%; RR, 1.23; P < .001). Additionally, the study demonstrated OUD patients incurred greater day of surgery ($14,384.30 vs $13,150.12, P < .0001) and 90-day costs ($21,183.82 vs $18,709.02, P < .0001) compared to controls.

Conclusion

After controlling for age, sex, a comorbidity index, and various medical complications, OUD patients are at greater risk to experience implant-related complications, PJIs, readmissions, and have greater costs following primary THA compared to non-OUD patients. This study should help orthopedic surgeons counsel their patients of potential complications which may arise following their primary THA.

Portable Accelerometer-Based Navigation System for Cup Placement of Total Hip Arthroplasty: A Prospective, Randomized, Controlled Study

30-09-2019 – Hiromasa Tanino, Yasuhiro Nishida, Ryo Mitsutake, Hiroshi Ito

Journal Article

Background

Malposition of the acetabular component during total hip arthroplasty (THA) is associated with increased risk of dislocation, reduced range of motion, and accelerated wear. The purpose of this study is to compare cup positioning with a portable, accelerometer-based hip navigation system and conventional surgical technique.

Methods

In a prospective, randomized, clinical study, cups were implanted with a portable, accelerometer-based hip navigation system (navigation group; n = 55) or conventional technique (conventional group; n = 55). THA was conducted in the lateral position and through posterior approach. The cup position was determined postoperatively on pelvic radiograph and computed tomography scans.

Results

An average cup abduction of 39.2° ± 4.6° (range, 27° to 50°) and an average cup anteversion of 14.6° ± 6.1° (range, 1° to 27.5°) were found in the navigation group, and an average cup abduction of 42.9° ± 8.0° (range, 23° to 73°) and an average cup anteversion of 11.6° ± 7.7° (range, −12.1° to 25°) in the conventional group. A smaller variation in the navigation group was indicated for cup abduction (P = .001). The deviations from the target cup position were significantly lower in the navigation group (P = .001, .016). While only 37 of 55 cups in the conventional group were inside the Lewinnek safe zone, 51 of 55 cups in the navigation group were placed inside this safe zone (P = .006). The navigation procedure took a mean of 10 minutes longer than the conventional technique.

Conclusion

Use of the portable, accelerometer-based hip navigation system can improve cup positioning in THA.

Simultaneous or Staged Bilateral Total Hip Arthroplasty? An Analysis of Complications in 14,460 Patients Using National Data

16-09-2019 – Thomas C.J. Partridge, John A.F. Charity, Nemandra A. Sandiford, Paul N. Baker, Mike R. Reed, Simon S. Jameson

Journal Article

Background

Simultaneous bilateral total hip arthroplasty (Sim
BTHA) is often performed in younger, fitter patients with bilateral hip disease. If patients are deemed not suitable for Sim
BTHA due to concurrent comorbidity, it may be more appropriate to perform staged bilateral total hip arthroplasties (St
BTHAs) 3-6 months apart to minimize complications and morbidity. Complication rates following hip arthroplasty are low and large national datasets are helpful for assessing these rare events. We aimed at comparing Sim
BTHA vs St
BTHA in order to determine any differences in morbidity and mortality.

Methods

Hospital Episode Statistics data for all patients who underwent bilateral THAs in the English National Health Service between April 2005 and July 2014 were obtained. Patients were grouped into Sim
BTHAs (same day) or staged, with the second THA occurring between 3 and 6 months after the first. Medical and surgical complications were compared and total length of stay was assessed.

Results

A total of 2507 underwent Sim
BTHAs and 9915 had St
BTHAs. Sim
BTHA patients were significantly younger (60.6 vs 65.5 years, P < .001) and more likely to be male, but had similar Charlson comorbidity scores. Compared to St
BTHAs, patients undergoing Sim
BTHAs had a greater risk of pulmonary embolism, myocardial infarction, renal failure, chest infection, and inhospital death. Patients undergoing Sim
BTHAs had a significantly shorter overall hospital stay (8.9 vs 10.4 days). Patients undergoing Sim
BTHA at high-volume units had a lower average Charlson score and subsequent complication rate than low-volume units.

Conclusion

These findings highlight the greater risks of Sim
BTHA in patients with Charlson score greater than 0 performed at lower-volume centers in England.

Prevalence of Sagittal Spinal Deformity Among Patients Undergoing Total Hip Arthroplasty

09-09-2019 – Aaron J. Buckland, Ethan W. Ayres, Andrew J. Shimmin, Jonathan V. Bare, Stephen J. McMahon, Jonathan M. Vigdorchik

Journal Article

Background

The important relationship between sagittal spinal alignment and total hip arthroplasty (THA) is becoming well recognized. Prior research has shown a significant relationship between sagittal spinal deformity (SSD) and THA instability. This study aims at determining the prevalence of SSD among preoperative THA patients.

Methods

A multicenter database of preoperative THA patients was analyzed. Radiographic parameters measured from standing radiographs included anterior pelvic plane tilt, spinopelvic tilt, and lumbar lordosis (LL); pelvic incidence (PI) was measured from computed tomography scans. Lumbar flatback was defined as PI-LL mismatch >10°, balanced as PI-LL of −10° to 10°, and hyperlordosis as PI-LL <−10°.

Results

A total of 1088 patients were analyzed (mean, 64 years; 48% female). And 59% (n = 644) of patients had balanced alignment, 16% (n = 174) had a PI-LL > 10°, and 4% (n = 46) had a PI-LL > 20° (severe flatback deformity). The prevalence of hyperlordosis was 25% (n = 270). Flatback patients tended to be older than balanced and hyperlordotic patients (69.5 vs 64.0 vs 60.8 years, P < .001). Spinopelvic tilt was more posterior in flatback compared to balanced and hyperlordotic patients (24.7° vs 15.4° vs 7.0°) as was anterior pelvic plane tilt (−7.1° vs −2.0° vs 2.5°) and PI (64.1° vs 56.8° vs 49.0°), all P < .001.

Conclusion

Only 59% of patients undergoing THA have normally aligned lumbar spines. Flatback SSD was observed in 16% (4% with severe flatback deformity) and there was a 25% prevalence of hyperlordosis. Lumbar flatback was associated with increasing age, posterior pelvic tilt, and larger PI. The relatively high prevalence of spinal deformity in this population reinforces the importance of considering spinopelvic alignment in THA planning and risk stratification.

Can We Help Patients Forget Their Joint? Determining a Threshold for Successful Outcome for the Forgotten Joint Score

12-09-2019 – Philip J. Rosinsky, Jeffrey W. Chen, Ajay C. Lall, Jacob Shapira, David R. Maldonado, Benjamin G. Domb

Journal Article

Background

Clinically important thresholds improve interpretability of patient-reported outcomes. A threshold for a successful outcome does not exist for the Forgotten Joint Score (FJS). The purpose of this study is to determine a threshold score for the FJS, 1 and 2 years after total hip arthroplasty (THA).

Methods

A retrospective analysis of 247 primary THA recipients between December 2012 and April 2017 was performed. A binary “successful treatment” was defined as achieving a composite criterion of pain, function, and satisfaction. Receiver operator characteristic analysis determined thresholds for successful outcome at 1 and 2 years postoperatively, subanalyzed by demographics. Results were validated by a 75th centile comparison. The ceiling effect of FJS was also assessed.

Results

The average FJS was 70.06 ± 29.39 and 75.05 ± 28.73 at 1 and 2 years, respectively (P < .001). The proportion of patients meeting the composite criteria for success was 66.8% at 1 year and 76.5% at 2 years (P = .017). The receiver operator characteristic analysis for FJS at 1 and 2 years yielded excellent accuracy as defined by area under the curve (0.91 and 0.92, respectively). The threshold values were 73.96 and 69.79 at the respective time points. A mild ceiling effect was found with 16% and 23% of cases achieving a score of 100 at 1 and 2 years, respectively.

Conclusion

The FJS has excellent accuracy in demonstrating successful outcome following THA. The FJS threshold for success at 1 and 2 years postoperatively is 73.96 and 69.79, respectively. The higher rates of success at 2 years, along with a rise in the mean FJS, may indicate continued clinical improvement up to 2 years after THA.

The Patient Acceptable Symptom State for the Harris Hip Score Following Total Hip Arthroplasty: Validated Thresholds at 3-Month, 1-, 3-, 5-, and 7-Year Follow-Up

15-09-2019 – Vincent P. Galea, Isabella Florissi, Pakdee Rojanasopondist, James W. Connelly, Lina H. Ingelsrud, Charles Bragdon, Henrik Malchau, Anders Troelsen

Journal Article

Background

The Patient Acceptable Symptom State (PASS) represents the value on a patient-reported outcome measure scale beyond which patients consider themselves well or in a satisfactory state. The aim of this study is to define and validate the PASS threshold for the HHS at 3 months, 1, 3, 5, and 7 years after THA.

Methods

A total of 976 patients from 14 centers in 7 countries were enrolled into a prospective study. Patients completed the HHS and a numerical rating scale for satisfaction at each follow-up. PASS thresholds for the HHS were calculated at each follow-up interval using the anchor-based, 80% specificity method. A bootstrapping method was used to internally validate the primary PASS thresholds. A patient sample sourced from an institutional registry was used for external validation.

Results

The HHS was an excellent predictor of satisfaction at each time point (area under the curve > 0.8; P < .001). PASS thresholds for the HHS were 76 points at 3 months, 89 points at 1 year, 93 points at 3 years, 94 points at 5 years, and 93 points at 7 years. When applied to the internal and external validation cohorts, all PASS thresholds showed acceptable or excellent ability to predict satisfaction (area under the curve = 0.73-80; P < .001).

Conclusion

The present study is the first to present validated PASS thresholds for the HHS following THA. These findings will serve as a useful reference for future THA outcome studies and as benchmarks for surgeons in their assessment of their patients’ clinical success.

Long-Term Implant Survivorship and Modes of Failure in Simultaneous Concurrent Bilateral Total Knee Arthroplasty

11-09-2019 – Taylor M. Yong, Emily C. Young, Ilda B. Molloy, Brian M. Fisher, Benjamin J. Keeney, Wayne E. Moschetti

Journal Article

Background

There is limited evidence describing long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty (TKA).

Methods

We performed a retrospective review of 266 consecutive patients (532 knees) who underwent simultaneous concurrent bilateral TKA. We reviewed medical records for preoperative characteristics, perioperative complications, and revision surgeries. The primary outcome was TKA survivorship. Secondary outcomes included indication and type of revision surgery. We used the Kaplan-Meier method to estimate survivorship and characterize risk of revision up to 20 years post-TKA.

Results

Our cohort had median follow-up of 9.8 years (interquartile range, 3.9-15.9). Forty-four patients (17%) underwent revision. Revision was more common among younger and male patients. The cumulative incidence of first-time revision per knee (n = 532) was 1.27 per 100 component-years. Implant survival was 99% (confidence interval, 97%-99%) at 5 years, 92% (89%-95%) at 10 years, 83% (77%-87%) at 15 years, and 62% (50%-73%) at 20 years. Five and 10-year survivorship compared favorably to estimates of TKA survivorship in the literature. The cumulative incidence of revision surgery per patient was 1.91 per 100 component-years. Implant survival at 5-, 10-, 15-, and 20-year time points was 96% (CI, 92%-98%), 84% (77%-89%), 71% (62%-79%), and 59% (46%-70%), respectively. Aseptic loosening (40%), polyethylene wear (34%), and infection (11%) were the most common indications for revision.

Conclusion

Simultaneous concurrent bilateral TKA is associated with a higher risk of reoperation for the patient when both knees are evaluated but similar implant survivorship to the literature when each knee was evaluated in isolation.

The Outcome of Total Knee Arthroplasty With and Without Patellar Resurfacing up to 17 Years: A Report From the Australian Orthopaedic Association National Joint Replacement Registry

04-09-2019 – Joseph A. Coory, Kelvin G. Tan, Sarah L. Whitehouse, Alesha Hatton, Stephen E. Graves, Ross W. Crawford

Journal Article

Background

Patellar resurfacing in total knee arthroplasty (TKA) remains a controversial issue after more than 4 decades of TKA. Despite a growing body of evidence from registry data, resurfacing is still based largely on a surgeon’s preference and training. The purpose of this study is to provide long-term outcomes for patellar resurfaced compared to when the patella is not resurfaced.

Methods

Data from the Australian Orthopaedic Association National Joint Replacement Registry (1999-2017) were used for this study. The analysis included 570,735 primary TKAs undertaken for osteoarthritis. Hazard ratios (HRs) and 17-year cumulative percent revision rates were used to compare revision rates between 4 subgroups: minimally stabilized (MS) patellar resurfacing, posterior stabilized (PS) patellar resurfacing, MS unresurfaced, and PS unresurfaced patella. Additional analyses of the patellar implant type and a comparison of inlay and onlay patellar resurfacing were also performed.

Results

For all primary TKA, procedures where the patella was not resurfaced have a higher rate of revision compared to procedures where the patella was resurfaced (HR, 1.31; confidence interval, 1.28-1.35; P < .001). Unresurfaced PS knees have the highest cumulative percent revision at 17 years (11.1%), followed by MS unresurfaced (8.8%), PS resurfaced (7.9%), and MS resurfaced (7.1%). Inlay patellar resurfacing has a higher rate of revision compared to onlay patellar resurfacing (HR, 1.27; confidence interval, 1.17-1.37; P < .001).

Conclusion

Resurfacing the patella reduces the rate of revision for both MS and PS knees. MS knees with patellar resurfacing have the lowest rate of revision. Onlay patella designs are associated with a lower revision rate compared to inlay patella designs.

The Natural History of Radiolucencies Following Uncemented Total Knee Arthroplasty at 9 Years

21-09-2019 – Timothy G. Costales, Danielle M. Chapman, David F. Dalury

Journal Article

Background

Aseptic loosening remains a common cause of failure in total knee arthroplasty (TKA). There is an increased interest in using uncemented TKA to reduce this complication. Radiolucencies (RLs) following uncemented TKA can be concerning. We report on the 9-year history of RLs in patients with uncemented TKA.

Methods

Twenty-one patients (26 knees) were treated with a cruciate-retaining fully porous coated femur/tibia and cemented patella. At final follow-up, 17 patients (22 knees) were available for review. Average follow-up was 9.6 years, average age was 59.1, and average body mass index was 34.1. X-rays were taken at 6 weeks, 1 year, and at final follow-up. RLs were measured using the Knee Society scoring system and read by two separate surgeons.

Results

At 6 weeks, we identified RL in all patients on both the tibia and femur. The majority were beneath the tibial tray and femoral chamfer. At 1 year, 4 femurs and 4 tibias showed new RLs (<2 mm) in similar zones. Eighteen femurs and 18 tibias showed fewer or no change in RLs. At final follow-up, no new tibia or femur developed a new RL. In total, 9 of the 22 tibias and 17 of the 22 femurs had remaining RLs, all less than 2 mm and none were progressive or new. Knee Society Score averaged 92.5 (6 weeks), 95.1 (1 year), and 97.3 (final).

Conclusion

RLs are common following uncemented TKA. Many resolve by 1 year. There does not appear to be any association between the presence of RLs and long-term follow-up function in this group of patients.

Using Cluster Analysis to Identify Patient Factors Linked to Differential Functional Gains After Total Knee Arthroplasty

19-09-2019 – Jeffrey K. Lange, Steven T. DiSegna, Wenyun Yang, Wenjun Li, Patricia D. Franklin

Journal Article

Background

The basis of poor outcomes following total knee arthroplasty (TKA) is multifactorial. Previous research aimed at predicting outcome following TKA focuses largely on outcomes measured between two specific time points (pre-to post-TKA). Analysis of outcomes measured over multiple time points (trajectory) may expose relationships between patients’ characteristics and longitudinal outcome patterns that may otherwise remain obscured.

Methods

The current study analyzed Short Form 36 Physical Component Score (PCS) trajectories of 656 patients composed of 3 time points over a 1-year period. Clusters were constructed utilizing Multi
Experiment Viewer hierarchical clustering algorithm. Statistical significance of these clusters was assessed using Me
V’s built-in bootstrapping method. Patient characteristics of the resulting statistically conserved clusters were summarized and compared using Wilcoxon rank-sum test or chi-squared test as appropriate.

Results

Two distinct clusters of outcome trajectory were identified. Cluster 1 included 550 patients (84%) who demonstrated persistent PCS improvement at 6 and 12 months. Cluster 2 included 106 patients (16%) who demonstrated decline in PCS at 6 months followed by improvement at 12 months. Cluster 1 achieved earlier success, greater absolute mental and physical health scores as compared to Cluster 2 (P < .05), and demonstrated higher baseline mental health scores, lower baseline PCS, and a significantly higher proportion of non-Hispanic Whites (P ≤ .05).

Conclusion

Cluster analysis identified distinct functional outcome trajectories following TKA. Specific differentiating patient factors were associated with differing trajectories. Future studies should focus on this method’s ability to inform predictive models regarding patient outcomes.

Higher Activity Level Following Total Knee Arthroplasty Is Not Deleterious to Mid-Term Implant Survivorship

01-09-2019 – David A. Crawford, Joanne B. Adams, Gerald R. Hobbs, Keith R. Berend, Adolph V. Lombardi

Journal Article

Background

The impact of a patient’s activity level following total knee arthroplasty (TKA) remains controversial, with some surgeons concerned about increased polyethylene wear, aseptic loosening, and revisions. The purpose of this study is to report on implant survivorship and outcomes of high activity patients compared to low activity patients after TKA.

Methods

A retrospective review identified 1611 patients (2038 knees) that underwent TKA with 5-year minimum follow-up. Patients were divided in 2 groups based on their University of California Los Angeles (UCLA) activity level: low activity (LA) (UCLA ≤5) and high activity (HA) (UCLA ≥6). Outcomes included range of motion, Knee Society scores, complications, and reoperations. Parametric survival analysis was performed to evaluate the significance of activity level on survivorship while controlling for age, gender, preoperative pain, Knee Society clinical scores, Knee Society functional scores, and body mass index (BMI).

Results

Mean follow-up was 11.4 years (range 5.1-15.9). The LA group had significantly more female patients, were older, had higher BMI, and had lower functional scores preoperatively (all with P < .001). The HA group had significantly higher improvements in Knee Society scores (P < .001) and pain postoperatively (P < .001). Revisions were performed in 4% of the LA group and 1.7% knees of the HA group (P = .003). After controlling for age, gender, preoperative pain, Knee Society clinical scores, Knee Society functional scores, and BMI, a higher postoperative activity level remained a significant factor for improved survivorship with an odds ratio of 2.4 (95% confidence interval 1.2-4.7, P = .011). The all-cause 12-year survivorship was 98% for the HA group and 95.3% for the LA group (P = .003). The aseptic 12-year survivorship was 98.4% for the HA group and 96.3% for the LA group (P = .02).

Conclusion

Highly active patients had increased survivorship at 5-year minimum follow-up compared to lower activity patients after TKA. Patient activity level after TKA may not need to be limited with modern implants.

Total Knee Arthroplasty Has A Positive Effect on Patients With Low Mental Health Scores

17-09-2019 – Patrick K. Horst, Andrew A. Barrett, James I. Huddleston, William J. Maloney, Stuart B. Goodman, Derek F. Amanatullah

Journal Article

Background

The purpose of this study is to determine the impact of total knee arthroplasty (TKA) on mental health.

Methods

A total of 205 patients who underwent primary TKA with baseline and 1-year postoperative Short Form-12 Mental Component Score (MCS) were included in this retrospective analysis. Eighty-five (41%) patients had a preoperative MCS less than 50 points, while 120 (59%) patients had a preoperative MCS over 50 points. Two groups were assigned to the patients based on their preoperative MCS: low MCS <50 and high MCS >50.

Results

A preoperative MCS less than 50 points was predictive of greater improvement in MCS at 1 year after TKA (P < .001). Patients with low MCS improved by a mean of 10.6 points from 39.1 ± 8.6 points preoperatively to mean of 49.7 ± 10.7 points 1 year after TKA (P < .001). Patients with a high MCS decreased by a mean of 3.5 points from 60.01 ± 6.0 points preoperatively to mean of 56.6 ± 6.8 points 1 year after TKA (P < .001). This remained higher than the postoperative MCS of the patients with a low MCS, 49.7 ± 10.7 (P < .001). The patients with a high MCS had greater improvement in the Short Form-12-Physical domain (14.8 points) than the patients with a low MCS (9.2 points, P < .001).

Conclusion

Patients with lower baseline mental health had greater improvement in postoperative mental health following TKA than patients with higher baseline mental health. Low preoperative MCS was associated with less improvement in patient-reported outcome measures. Patients with lower baseline mental health scores before TKA benefit mentally and physically from the procedure.

Midterm Effect of Mental Factors on Pain, Function, and Patient Satisfaction 5 Years After Uncomplicated Total Knee Arthroplasty

04-09-2019 – Sebastian Bierke, Martin Häner, Katrin Karpinski, Tilman Hees, Wolf Petersen

Journal Article

Background

The effects of psychological factors on the short-term outcome after uncomplicated total knee arthroplasty (TKA) have been described in several studies. However, the effects of mental factors on the midterm (5-year) outcome have not been described in the literature. This study was performed to examine the influence of pain catastrophizing, anxiety, depression symptoms, and somatization dysfunction on the outcome of TKA during a 5-year follow-up.

Methods

One hundred fifty patients were enrolled in this prospective study. The following mental parameters were assessed in all patients: pain catastrophizing (Pain Catastrophizing Scale), anxiety (State-Trait Anxiety Inventory), depressive symptoms and somatization dysfunction (Patient Health Questionnaire). The primary outcome measure was postoperative pain on a numerical rating scale. The secondary outcome measures were the Knee Injury and Osteoarthritis Outcome Score and patient satisfaction. Intergroup differences were tested using an independent t-test. Odds ratios were calculated to determine the probability of an unsatisfactory outcome.

Results

At the 5-year follow-up, only depressive symptoms and somatization dysfunction had a significant effect on postoperative pain (numerical rating scale score). This significant effect was also observed for the different Knee Injury and Osteoarthritis Outcome Score subscales and patient satisfaction (P = .010-.020). Pain catastrophizing and anxiety had only a small effect on the clinical outcome at 5 years postoperatively.

Conclusion

The effects of psychopathological factors (depressive symptoms and somatization dysfunction) on the clinical outcome after uncomplicated TKA persist for up to 5 years. Preoperative screening for and subsequent treatment of these psychological disorders may improve patient-reported outcomes after TKA.

Level of Evidence

Level II, diagnostic study.

Prior Knee Arthroscopy Is Associated With Increased Risk of Revision After Total Knee Arthroplasty

25-09-2019 – Alex Gu, Michael-Alexander Malahias, Jordan S. Cohen, Shawn S. Richardson, Seth Stake, Jason L. Blevins, Peter K. Sculco

Journal Article

Background

Knee arthroscopy (KA) is frequently performed to provide improved joint function and pain relief. However, outcomes following total knee arthroplasty (TKA) after prior KA are not fully understood. The purpose of this study is to determine the relationship between prior KA within 2 years of TKA on revision rates after TKA.

Methods

Data were collected from the Humana insurance database using the Pearl
Diver Patient Records Database from 2006 to 2017. Subjects were identified using Current Procedural Terminology and International Classification of Diseases procedure codes to identify primary TKA. Patients were stratified into 2 groups based upon a history of prior KA. Univariate and multivariate analyses were conducted to determine association between KA and outcomes at 2-year postoperative period.

Results

In total, 138,019 patients were included in this study, with 3357 (2.4%) patients receiving a KA before TKA and 134,662 (97.6%) patients who did not. The most common reason for KA was osteoarthritis (40.0%), followed by medial tear of the meniscus (26.0%) and chondromalacia (21%.0). After adjustment, prior KA was associated with increased revision rate (odds ratio OR, 1.392; P = .003), postoperative stiffness (OR, 1.251; P = .012), periprosthetic joint infection (OR, 1.326; P < .001), and aseptic loosening (OR, 1.401; P = .048).

Conclusion

Prior KA is significantly associated with increased 2-year TKA revision rate. The most common etiology for arthroscopy was osteoarthritis. The results of the study, showing that arthroscopy before TKA substantially increases the rates of revision, PJI, aseptic loosening, and stiffness, lend further credence to the idea that patients may be better served by nonsurgical management of their degenerative pathology until they become candidates for TKA. Subjecting this population to arthroscopy appears to offer limited benefit at the cost of poorer outcomes when they require arthroplasty in the future.

Level of Evidence

Level III therapeutic study.

Increased Medical Complications, Revisions, In-Hospital Lengths of Stay, and Cost in Patients With Hypogonadism Undergoing Primary Total Knee Arthroplasty

23-09-2019 – Andrew D. Ardeljan, Zaimary A. Meneses, Bryan V. Neal, Rushabh M. Vakharia, Martin W. Roche

Journal Article

Background

Research regarding the impact of hypogonadism following primary total knee arthroplasty (TKA) is limited. Therefore, the purpose of this study is to investigate whether patients with hypogonadism undergoing primary TKA are at increased odds of (1) medical complications, (2) revisions, (3) in-hospital lengths of stay (LOSs), and (4) cost of care.

Methods

A Humana patient population consisting of 8 million lives was retrospectively analyzed from 2007 to 2017 using International Classification of Disease, 9th Revision codes. Patients were filtered by male gender and patients with hypogonadism were matched to controls in a 1:4 ratio according to age and medical comorbidities. The query yielded 8393 patients with (n = 1681) and without (6712) hypogonadism undergoing primary TKA. Primary outcomes analyzed included medical complications, revision rates, in-hospital LOS, and cost of care. Logistic regression analysis was used to calculate odds ratios (OR) of 90-day medical complications and 2-year revisions. Welch’s t-test was used to test for significance in LOS and cost of care between cohorts. A P-value less than .05 was considered statistically significant.

Results

Hypogonadal patients undergoing primary TKA were found to have increased incidence and odds (9.45% vs 4.67%; OR 2.12, P < .0001) of developing 90-day medical complications. Hypogonadal patients undergoing primary TKA were found to have a greater incidence and odds (3.99% vs 2.80%; OR 1.89, P < .0001) of 2-year revisions. Hypogonadal patients had a 6.11% longer LOS (3.47 vs 3.27 days, P = .02) compared to controls, and incurred greater 90-day costs ($15,564.31 vs $14,856.69, P = .018) compared to controls.

Conclusion

This analysis of over 1600 patients demonstrates that patients with hypogonadism undergoing primary TKA have greater odds of postoperative medical complications, revisions, increased LOS, and cost of care.

Evolution of an Opioid Sparse Pain Management Program for Total Knee Arthroplasty With the Addition of Intravenous Acetaminophen

16-09-2019 – Stephen Yu, Nima Eftekhary, Daniel Wiznia, Ran Schwarzkopf, William J. Long, Joseph A. Bosco, Richard Iorio

Journal Article

Background

Perioperative pain management for patients undergoing total knee arthroplasty (TKA) improves patient outcomes and facilitates recovery. In this study, we compared the effects of preoperative oral acetaminophen vs intravenous (IV) acetaminophen administered once intraoperatively and once postoperatively.

Methods

Two standardized, multimodal analgesia protocols were compared in patients undergoing primary, unilateral TKA. The oral acetaminophen cohort (OA) received doses of oral acetaminophen preoperatively and an as-needed basis postoperatively (n = 698). The IV acetaminophen cohort (IA) received 2 doses of IV acetaminophen, one intraoperative and one 6 hours postoperatively, with no oral acetaminophen given (n = 318). No other variables were significantly changed during the study period.

Results

The IV acetaminophen group demonstrated less narcotic usage on postoperative day 0 (OA: 13.3 mme morphine mg equivalents, IA: 6.2 mme, P < .001) and overall usage (OA: 66.1 mme, IA: 48.5 mme, P < .001). Pain scores were statistically and clinically significantly decreased in the immediate postoperative (the first 8 hours) for the IA group (OA: patient-reported pain scores of 4.0; IA: patient-reported pain scores of 2.0, P < .001). Both groups progressed and completed their physical therapy similarly for each postoperative day. Length of stay and percent discharge home were slightly improved in the IA group as well, however did not reach statistical difference.

Conclusion

An iterative approach to multimodal pain management after TKA led to improvements in narcotic usage, pain scores, and several quality measures. IV acetaminophen is an integral and effective part of our opioid-sparing multimodal pain regimen in TKA.

Modifiable, Postoperative Risk Factors for Delayed Discharge Following Total Knee Arthroplasty: The Influence of Hypotension and Opioid Use

11-09-2019 – Albert T. Anastasio, Kevin X. Farley, Scott D. Boden, Thomas L. Bradbury, Ajay Premkumar, Michael B. Gottschalk

Journal Article

Background

We sought to identify independent modifiable risk factors for delayed discharge after total knee arthroplasty (TKA) that have been previously underrepresented in the literature, particularly postoperative opioid use, postoperative laboratory abnormalities, and the frequency of hypotensive events.

Methods

Data from 1033 patients undergoing TKA for primary osteoarthritis of the knee between June 2012 and August 2014 at an academic orthopedic specialty hospital were reviewed. Patient demographics, comorbidities, inpatient opioid medication, postoperative hypotensive events, and abnormalities in laboratory values, all occurring on postoperative day 0 or 1, were collected. Multivariate logistic regression analysis was performed to identify independent risk factors for a prolonged length of stay (LOS) >3 days.

Results

The average age of patients undergoing primary TKA in our cohort was 65.9 (standard deviation, 9.1) years, and 61.7% were women. The mean LOS for all patients was 2.64 days (standard deviation, 1.14; range, 1-9). And 15.3% of patients had a LOS >3 days. On multivariate logistic regression analysis, nonmodifiable risk factors associated with a prolonged LOS included nonwhite race (odds ratio OR, 2.01), single marital status (OR, 1.53), and increasing age (OR, 1.47). Modifiable risk factors included every 5 postoperative hypotensive events (OR, 1.31), 10-mg increases in oral morphine equivalent consumption (OR, 1.04), and postoperative laboratory abnormalities (hypocalcemia: OR, 2.15; low hemoglobin: OR, 2.63).

Conclusion

This study identifies potentially modifiable factors that are associated with increased LOS after TKA. Doubling down on efforts to control the narcotic use and to use opioid alternatives when possible will likely have efficacy in reducing LOS. Attempts should be made to correct laboratory abnormalities and to be cognizant of patient opioid use, age, and race when considering potential avenues to reduce LOS.

The Hemodynamic Effect of Epinephrine-Containing Local Infiltration Analgesia After Tourniquet Deflation During Total Knee Arthroplasty: A Retrospective Observational Study

23-09-2019 – Seokha Yoo, Jae-Yeon Chung, Du Hyun Ro, Hyuk-Soo Han, Myung Chul Lee, Jin-Tae Kim

Journal Article

Background

Local infiltration analgesia (LIA) is widely used in patients undergoing total knee arthroplasty and often contains epinephrine for a prolonged analgesic effect and to reduce systemic absorption of the local anesthetic. This retrospective observational study investigated the hemodynamic effect of locally infiltrated epinephrine after deflation of the tourniquet during total knee arthroplasty.

Methods

We reviewed the electronic medical records of patients who underwent total knee arthroplasty between January 2017 and February 2018 at a tertiary care university hospital. Total knee arthroplasty was performed using a conventional technique with a pneumatic tourniquet. LIA consisted of ropivacaine, morphine sulfate, ketorolac, and methylprednisolone. The patients were grouped according to whether or not epinephrine was included in the LIA. The incidence of a hypertensive response (systolic blood pressure >160 mm
Hg or mean blood pressure >110 mm
Hg) after deflation of the tourniquet was compared between the 2 groups.

Results

A total of 452 patients had received LIA with (n = 188) or without (n = 264) epinephrine. A hypertensive response after deflation of the tourniquet was more common in patients who received LIA containing epinephrine (42/188 22.3%) than in those who received LIA without epinephrine (14/264 5.3%, P < .001). However, the incidence of hypotension after deflation of the tourniquet was not significantly different between the 2 groups (P = .976).

Conclusion

Because epinephrine-containing LIA can result in a hypertensive response after deflation of the tourniquet during total knee arthroplasty, it should be cautiously administered, especially in patients with cardiovascular comorbidities.

Efficacy of Systemic Steroid Use Given One Day After Total Knee Arthroplasty for Pain and Nausea: A Randomized Controlled Study

30-09-2019 – Jong-Keun Kim, Du Hyun Ro, Han-Jin Lee, Jae-Young Park, Hyuk-Soo Han, Myung Chul Lee

Journal Article

Background

Systemic steroid has been used to control pain and nausea in total knee arthroplasty (TKA), but most studies recommend a single dose administration prior to, or during, surgery. This study aimed to determine the efficacy of administration on 1 day postoperatively.

Methods

Patients who were scheduled to undergo TKA were randomly assigned to the following groups: control group, receiving normal saline injection; group 1, receiving 10 mg dexamethasone intravenously (IV) 1 hour before surgery; group 2, receiving 0.1 mg/kg dexamethasone (IV) 24 hours after surgery; or group 3, receiving 0.2 mg/kg dexamethasone (IV) 24 hours after surgery (n = 44-46 per group). Primary outcomes were pain and nausea visual analogue scale (VAS). Secondary outcomes were analgesic administration, rescue antiemetic administration, C-reactive protein, range of motion, and complications.

Results

Postoperative pain and nausea remained high for 48 hours post-TKA. Group 1 had lower pain and nausea VAS scores than did the control group (P < .01) for only 24 hours post-TKA. Groups 2 and 3 had lower pain and nausea VAS scores than did the control group and group 1 (P < .01) 48 hours post-TKA. Analgesic and antiemetic administration were significantly lower in groups 2 and 3 than in the control group during 48 hours after TKA. There were no differences in C-reactive protein level and range of motion, and complications were not detected.

Conclusion

The effect of preoperative and postoperative administration of dexamethasone for controlling pain and nausea was observed only for 24 hours. Considering that severe pain and nausea persisted for more than 48 hours after TKA, additional administration of dexamethasone at 1 day postoperatively is suggested.

Level of Evidence

Level I.

Hemostatic and Anti-Inflammatory Effects of Carbazochrome Sodium Sulfonate in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Trial

01-09-2019 – Yue Luo, Xin Zhao, Yeersheng Releken, Zhouyuan Yang, FuXing Pei, Pengde Kang

Journal Article

Background

Postoperative recovery after total knee arthroplasty (TKA) is associated with postoperative anemia, allogeneic transfusion, and stress immune responses to surgery. Carbazochrome sodium sulfonate (CSS) reduces bleeding through several mechanisms. We assessed the effect of CSS combined with tranexamic acid (TXA) on postoperative anemia, blood transfusion, and inflammatory responses.

Methods

This study was designed as a randomized, placebo-controlled trial of 200 patients undergoing unilateral primary TKA. Patients were divided into 4 groups: group A received TXA plus topical and intravenous CSS; group B received TXA plus topical CSS only; group C received TXA plus intravenous CSS only; group D received TXA only.

Results

Total blood loss in groups A (609.92 ± 221.24 m
L), B (753.16 ± 247.67 m
L), and C (829.23 ± 297.45 m
L) was lower than in group D (1158.26 ± 334.13 m
L, P < .05). There was no difference in total blood loss between groups B and C. We also found that compared with group D, the postoperative swelling rate, biomarker level of inflammation, visual analog scale pain score, and range of motion at discharge in groups A, B, and C were significantly improved (P < .05). No thromboembolic complications occurred. There were no differences in transfusion rate, intraoperative blood loss, platelet count, or average length of stay among the 4 groups (P > .05).

Conclusion

CSS combined with TXA was more effective than TXA alone in reducing perioperative blood loss and inflammatory response and did not increase the incidence of thromboembolism complications.

Isolated Patellofemoral Joint Arthroplasty: Can Preoperative Bone Scans Predict Survivorship?

10-09-2019 – James F. Baker, David N. Caborn, Thomas J. Schlierf, Trevor B. Fain, Langan S. Smith, Arthur L. Malkani

Journal Article

Background

Isolated patellofemoral joint arthritis has been identified in 10% of the population presenting with symptomatic knee osteoarthritis. Patient selection is important in order to improve survivorship following PF arthroplasty. The purpose of this study is to compare the use of a preoperative bone scan vs a magnetic resonance imaging (MRI) to identify the patient with isolated PF arthritis.

Methods

This is a retrospective review of 32 patients undergoing isolated PF arthroplasty for PF arthritis using the same implant design. Sixteen consecutive patients received a preoperative bone scan to confirm isolated PF arthritis. These patients were matched by age and gender to patients where an MRI was used to determine isolated PF arthritis. The bone scan cohort contained 13 females and three males with an average age of 48 years and average follow-up of 52 months. There was no significant difference in age, body mass index, follow-up, or preoperative range of motion between the groups. The MRI and bone scan results were reported by a radiologist specializing in orthopedic radiology.

Results

Survivorship was 100% in the PF arthroplasty group selected using a preoperative bone scan. Revision surgery with conversion to TKA was required in 5 of 16 patients (31%) when an MRI was used to identify isolated PF arthritis. Revision in all patients in the MRI group was due to progression of knee arthritis in the tibial-femoral joint. There were no cases of implant-related failures.

Conclusion

Patellofemoral arthroplasty using a modern design implant demonstrated 100% survivorship when a preoperative bone scan was used for patient selection to confirm isolated PF arthritis. In the group where only an MRI was used, there was a 31% failure due to progression of the disease. Based on this study, we would recommend the use of a bone scan as a tool in the selection criteria for patients undergoing PF arthroplasty.

Five Questions to Identify Patients With Osteoarthritis of the Knee

30-09-2019 – Bernhard Springer, Ulrich Bechler, Wenzel Waldstein, Kilian Rueckl, Friedrich Boettner

Journal Article

Background

To treat the increasing number of patients with osteoarthritis (OA) of the knee, high-volume institutions rely on central referral services as first contact point. Depending on the grading of arthritis, patients will be referred to a nonoperative or operative care provider. The present study reports on a simple 5-step questionnaire to identify patients with OA (Kellgren/Lawrence KL grade ≥2) of the knee to improve efficiency of referrals.

Methods

We included 998 patients who contacted the physician referral service at the author’s institution complaining of knee pain and divided them into 2 groups. The study group included patients with an appointment and consisted of 646 patients (345 women 53.4% and 301 men 46.6%). X-rays of the knee were graded according to the KL classification system. The control group of patients who did not make an appointment consisted of 352 patients (187 women 53.1% and 165 men 46.9%). These patients were contacted to evaluate whether they had been diagnosed with OA of the knee since their initial call, to assure that the study group was not exposed to a selection bias.

Results

Logistic regression revealed 5 questions as significant predictors for OA of the knee (KL grade ≥2). When combining both groups, an 86.9% sensitivity, a 73.3% specificity, and an 84.3% overall accuracy were reached, when patients answered 3 or more questions positively.

Conclusion

The present study revealed a simple 5-step questionnaire to identify patients with OA of the knee. Implementation of the questionnaire has the potential to improve the accuracy of referral processes and streamline organization before the first appointment.

Tranexamic Acid Administration Is Not Associated With an Increase in Complications in High-Risk Patients Undergoing Primary Total Knee or Total Hip Arthroplasty: A Retrospective Case-Control Study of 38,220 Patients

17-09-2019 – Steven B. Porter, Launia J. White, Osayande Osagiede, Christopher B. Robards, Aaron C. Spaulding

Journal Article

Background

Tranexamic acid (TXA) administration to reduce postoperative blood loss and transfusion is a well-established practice for total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, clinical concerns remain about the safety of TXA in patients with a history of a prothrombotic condition. We sought to determine the risk of complications between high-risk and low-risk TKA and THA patients receiving TXA.

Methods

We retrospectively reviewed 38,220 patients (8877 high-risk cases) who underwent primary TKA and THA between 2011 and 2017 at our institution. Intravenous TXA was administered in 20,501 (54%) of cases. The rates of thrombotic complications (deep vein thrombosis DVT, pulmonary embolism PE, myocardial infarction MI, and cerebrovascular accident CVA) as well as mortality and readmission were assessed at 90 days postoperatively. Additionally, we evaluated 90-day postoperative occurrence of DVT and PE separate from occurrence of MI and CVA. Patients were categorized as high risk if they had a past medical history of a prothrombotic condition prior to surgery.

Results

There was no significant difference in the odds of these adverse outcomes between high-risk patients who received TXA and high-risk patients who did not receive TXA (odds ratio OR 1.00, 95% confidence interval CI 0.85-1.18). There were also no differences when evaluating the odds of 90-day postoperative DVT and PE (OR 0.84, 95% CI 0.59-1.19) nor MI and CVA (OR 0.91, 95% CI 0.56-1.49) for high-risk patients receiving TXA vs high-risk patients who did not receive TXA.

Conclusion

TXA administration to high-risk TKA and THA patients is not associated with a statistically significant difference in adverse outcomes. We present incremental evidence in support of TXA administration for high-risk patients undergoing primary arthroplasties.

Total Joint Arthroplasty in the Morbidly Obese: How Body Mass Index ≥40 Influences Patient Retention, Treatment Decisions, and Treatment Outcomes

19-09-2019 – Cameron W. Foreman, John J. Callaghan, Timothy S. Brown, Jacob M. Elkins, Jesse E. Otero

Journal Article

Background

The United States is in an obesity epidemic. Obesity has multiple common comorbid conditions, including lower extremity arthritis. We sought to examine the course of treatment for a population with body mass index (BMI) ≥40 kg/m2 and osteoarthritis (OA) of the hip or knee. We investigated decision criteria that influenced arthroplasty surgeons to recommend nonoperative management vs total joint arthroplasty (TJA). For those patients who ultimately received TJA, we compared outcomes in this population to those with BMI <40 kg/m2.

Methods

This study retrospectively reviewed 158 new patients with BMI ≥40 kg/m2 and moderate/severe OA of the hip or knee. Demographics, comorbidity profiles, and weight loss were compared between groups that underwent TJA and those that did not. The arthroplasty database was used to identify patients who underwent TJA during 2016-2018 (N = 1473). Comorbidities, readmissions, surgical site infections, and overall complications were compared between those with BMI ≥40 kg/m2 and BMI <40 kg/m2.

Results

About 51.3% of new patients with BMI ≥40 kg/m2 and moderate/severe OA did not return for a second clinic visit. Of those who did return, 42.9% eventually underwent surgery. BMI was higher in single visit patients vs those with multiple visits (49.5 vs 46.3 kg/m2, P < .001), no difference in those scheduled on an “as-needed” basis vs a specific return date (P = .18), and did not change significantly during the 2-year follow-up (P = .41). Patients who underwent TJA had a lower mean BMI at presentation than their nonoperative counterparts (44.5 vs 47.6 kg/m2, P < .01) and demonstrated significant weight loss prior to surgery (44.5 vs 42.6 kg/m2, P < .05). When comparing patients with BMI ≥40 kg/m2 vs BMI <40 kg/m2, overall complications were not higher in the BMI ≥40 kg/m2 group, although surgical site infections were higher in those undergoing total hip arthroplasty with BMI ≥40 kg/m2 (0.3% vs 3.1%, P < .05).

Conclusion

A majority of patients with BMI ≥40 kg/m2 and moderate/advanced OA will be lost to orthopedic follow-up. A relatively lower BMI indicates a greater chance of retention in care, and ultimately surgery, but does not influence surgeons’ recommendations to continue orthopedic management. Patients who persist in seeking treatment, lose significant weight, and exhaust nonoperative alternatives may be suitable for TJA despite a BMI ≥40 kg/m2, with an overall complication rate of 4.3%. However, only 9% of patients at 2-year follow-up achieved BMI <40 kg/m2 and only 20% of surgeries were performed on patients who had achieved this proposed cutoff.

Changes in Patient Satisfaction Following Total Joint Arthroplasty

08-09-2019 – Vincent P. Galea, Pakdee Rojanasopondist, James W. Connelly, Charles R. Bragdon, James I. Huddleston, Lina H. Ingelsrud, Henrik Malchau, Anders Troelsen

Journal Article

Background

The primary aim is to identify the degree to which patient satisfaction with the outcome of total hip arthroplasty (THA) or total knee arthroplasty (TKA) changes between 1 and 3 years from the procedure. The secondary aim is to identify variables associated with satisfaction.

Methods

Data were sourced from 2 prospective international, multicenter studies (919 THA and 450 TKA patients). Satisfaction was assessed by a 10-point numerical rating scale, at 1- and 3-year follow-up. Linear mixed-effects models were used to assess factors associated with satisfaction.

Results

For the THA cohort, higher preoperative joint space width (odds ratio OR = 0.28; P = .004), pain from other joints (OR = 0.26; P = .033), and lower preoperative health state (OR = −0.02; P < .001) were associated with consistently lower levels of satisfaction. The model also showed that patients with preoperative anxiety/depression improved in satisfaction between 1 and 3 years (OR = −0.26; P = .031).

For the TKA cohort, anterior (vs neutral or posterior) tibial component slope (OR = 0.90; P = .008), greater femoral component valgus angle (OR = 0.05; P = .012), less severe osteoarthritis (OR = −0.10; P < .001), and lower preoperative health state (OR = −0.02; P = .003) were associated with lower levels of satisfaction across the study period. In addition, patients with anterior tibial component slope improved in satisfaction level over time (OR = −0.33; P = .022).

Conclusion

Changes in satisfaction following THA and TKA are rare between 1- and 3-year follow-up. The findings of this study can be used to guide patient counseling preoperatively and to determine intervals of routine follow-up postoperatively.