Spine

Spine

“Niyan Platformed Tiered Building, Fuzhou, Jiangxi Province, China”

01-11-2019 –

Journal Article

No abstract available

In Vitro Biomechanical Validation of a Self-Adaptive Ratchet Growing Rod Construct for Fusionless Scoliosis Correction

01-11-2019 – Chen, Zong-Xing; Kaliya-Perumal, Arun-Kumar; Niu, Chi-Chien; Wang, Jaw-Lin; Lai, Po-Liang

Journal Article

Study Design. In vitro biomechanical evaluation of a novel self-adaptive unidirectional ratchet growing rod (RGR) system.
Objective. The aim of this study was to propose and biomechanically validate a novel RGR construct in vitro using porcine thoracic spines and calculate the tensile force required to elongate the RGR with springs, without springs, and with soft tissue encapsulation (induced in vivo in rabbits).
Summary of Background Data. Literature lacks clear consensus regarding the implant of choice for early-onset scoliosis. Multiple systems are currently available, and each has its own advantages and disadvantages. Therefore, studying novel designs that can credibly accommodate growth and curb deformity progression is of principle importance.
Methods. In vitro biomechanical motion tests were done using six porcine thoracic spines with pedicle screws at T3 and T8. A pure moment of ±5 Nm was loaded in lateral bending (LB) and flexion-extension. Range of motion (ROM) and neutral zone (NZ) of each specimen was determined after connecting the free movable growing rods (FGRs), RGRs, and standard rods (SRs). Tensile tests were done to measure the force required to elongate the RGR with springs, without springs, and with soft tissue encapsulation (induced in vivo in rabbits).
Results. Global ROM, implanted T3-T8 ROM, and the NZ of specimens with FGRs and RGRs were significantly higher than that with SRs. The RGRs favored unidirectional elongation in both LB and flexion. The tensile forces required for elongating the RGR without springs, with springs, and with soft tissue capsulation (by a scaled unit of 3 mm) were 3 ± 1.3 N, 10.5 ± 0.4 N, and 48.4 ± 14.4 N, respectively.
Conclusion. The RGR could stabilize and favor unidirectional elongation of the implanted spinal column when appropriate forces were present. There was no device failure as far as we have studied and it is anticipated that, with further safety and feasibility assessment, RGRs could be adapted for clinical use.
Level of Evidence: N/A

Implant Design and the Anchoring Mechanism Influence the Incidence of Heterotopic Ossification in Cervical Total Disc Replacement at 2-year Follow-up

01-11-2019 – Mehren, Christoph; Wuertz-Kozak, Karin; Sauer, Daniel; Hitzl, Wolfgang; Pehlivanoglu, Tuna; Heider, Franziska

Journal Article

Study Design. A nonrandomized, prospective, and single-center clinical trial.
Objective. The aim of this study was to determine whether the prosthesis design, and especially changes in the primary anchoring mechanism between the keel-based Pro
Disc C and the spike-based Pro
Disc Vivo, affects the frequency of heterotopic ossification (HO) formation over time.
Summary of Background Data. The occurrence of motion-restricting HO as well as underlying risk factors has so far been a widely discussed, but not well understand phenomenon. The anchoring mechanism and the opening of the anterior cortex may be possible causes of this unwanted complication.
Methods. Forty consecutive patients treated with the Pro
Disc C and 42 consecutive patients treated with the Pro
Disc Vivo were compared with respect to radiological and clinical outcome, with 2 years of follow-up. Clinical outcome scores included the Neck Disability Index (NDI), Visual Analogue Scale (VAS), and arm and neck pain self-assessment questionnaires. Radiological outcomes included the segmental lordosis and range of motion (ROM) of the index-segment as well as the occurrence of HO.
Results. The clinical outcome parameters improved in both groups significantly. Pro
Disc C: VAS arm and neck pain from 6.3 and 6.2 preoperatively to 0.7 and 1.3; NDI from 23.0 to 3.7; Pro
Disc Vivo: VAS arm and neck pain from 6.3 and 4.9 to 1.4 and 1.6, NDI from 34.1 to 8.7; 2-year follow-up (FU). The Pro
Disc Vivo cohort demonstrated a significantly lower incidence of HO than the Pro
Disc C group at 1-year FU (P = 0.0005) and 2-year FU (P = 0.005). Specifically, high-grade HO occurred in 9% versus 31%.
Conclusion. These findings demonstrate that prosthesis designs that allow primary anchoring without violation of the cortical surface help to reduce the incidence of severe ossification, possibly affecting the functionality and mobility of the artificial disc device over of time.
Level of Evidence: 3

Postoperative Resolution of MR T2 Increased Signal Intensity in Cervical Spondylotic Myelopathy: The Impact of Signal Change Resolution on the Outcomes

01-11-2019 – Machino, Masaaki; Ando, Kei; Kobayashi, Kazuyoshi; Ota, Kyotaro; Morozumi, Masayoshi; Tanaka, Satoshi; Ito, Keigo; Kato, Fumihiko; Ishiguro, Naoki; Imagama, Shiro

Journal Article

Study Design. A prospective comparative imaging study.
Objective. This study investigated whether postoperative resolution of spinal cord increased signal intensity (ISI) reflected symptom improvement and surgical outcomes in cervical spondylotic myelopathy (CSM) patients.
Summary of Background Data. Although some CSM patients exhibit magnetic resonance imaging (MRI) ISI, its alteration and resolution have not been investigated. The association between postoperative ISI resolution and surgical outcomes in CSM patients remains controversial.
Methods. A total of 505 consecutive CSM patients (311 males; 194 females) aged a mean of 66.6 years (range, 41–91) were enrolled. All were treated with laminoplasty and underwent MRI scans preoperatively and after an average of 26.5 months postoperatively (range 12–66 months). ISI was classified pre- and postoperatively based on sagittal T2-weighted magnetic resonance images into Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The patients’ pre- and postoperative neurological statuses were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy Japanese Orthopedic Association (JOA) score and other quantifiable tests, including the 10-s grip and release (10-s G&R) test and 10-s step test.
Results. A total of 337 patients showed preoperative ISI. Among these, 42 (12.5%) showed postoperative ISI resolution, associated with better postoperative JOA score and recovery rate, 10-s G&R and 10-s step test scores than those who retained it. Patients with preoperative Grade 2 ISI had no postoperative ISI resolution. Patients with ISI improvement from Grade 1 to Grade 0 had better outcomes than those with ISI worsening from Grade 1 to Grade 2.
Conclusion. Postoperative ISI resolution in CSM patients reflects postoperative symptoms and surgical outcomes. Patients who exhibit ISI resolution have better clinical outcomes.
Level of Evidence: 3

Does Disordered Sleep Moderate the Relationship Between Pain, Disability and Downstream Health Care Utilization in Patients With Low Back Pain?: A Longitudinal Cohort From the US Military Health System

01-11-2019 – Rhon, Daniel I.; O’Hagan, Edel; Mysliwiec, Vincent; Lentz, Trevor A.

Journal Article

Study Design. Prospective cohort.
Objective. The purpose of this study was to evaluate the influence of disordered sleep on the relationship between pain and health care utilization (HCU) and pain-related disability and HCU in individuals with low back pain (LBP).
Summary of Background Data. Disordered sleep and pain influence LBP outcomes, but their relationship with health care seeking after an episode of LBP has not been investigated and could help identify who is at risk for long-term medical care.
Methods. This study included patients with LBP participating in a self-management class at a large US military hospital between March 1, 2010 and December 4, 2012. Pain intensity, disability (Oswestry Disability Index), and sleepiness (Epworth Sleepiness Scale) were captured at baseline. Medical visits for a sleep disorder in the 12 months before the class and LBP-related healthcare utilization for the 12 months following the class were abstracted from the Military Health System Data Repository. Separate multivariate analyses evaluating pain intensity and disability as predictors of HCU were developed, with sleepiness and the presence of a sleep disorder as potential moderators. Analyses were adjusted for age, sex, history of back pain, and mental health comorbidities.
Results. A total of 757 consecutive participants were included, with 195 (26.8%) diagnosed with a subsequent sleep disorder. Sleepiness was not a significant predictor of HCU. The main effects of disability, pain intensity, and presence of a sleep disorder were significant across all analyses, with higher disability, pain intensity, and presence of a sleep disorder associated with higher predicted visits and costs for LBP. The presence of a sleep disorder was not a significant moderator in any model.
Conclusion. Higher pain intensity and disability predicted higher pain-related HCU in the year following a LBP self-management class. The presence of a sleep disorder diagnosis, as recorded in medical records, had a significant independent effect on LBP-related health care visits and costs beyond the influences of pain intensity, disability, and other key demographic and health-related characteristics, but did not moderate these relationships.
Level of Evidence: 3

Dual Time-Point 18F-FDG PET/CT in Spinal Sarcoidosis: A Single Institution Case Series

01-11-2019 – Ordóñez-Rubiano, Edgar G.; Solano-Noguera, Diego F.; Row, William; Weinberg, Jeffrey; Tatsui, Claudio E.; Johnson, Jason M.; Gule-Monroe, Maria K.

Study Design. A case series of dual time-point 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) for the diagnosis of spinal cord sarcoidosis.
Objective. The aim of this study was to illustrate three cases of spinal sarcoidosis with occult presentation and subsequent identification with the use of dual time-point 18F-FDG PET/CT.
Summary of Background Data. Sarcoidosis of the spinal cord is very rare and when it occurs without systemic manifestations of disease can be a challenging diagnostic dilemma frequently resulting in the need for spinal cord biopsy in order to establish a diagnosis.
Methods. Case series presentation and report.
Results. This manuscript presents a case series experience of dual time-point 18F-FDG PET/CT for the diagnosis of spinal cord sarcoidosis. We review the cases of three patients who presented with myelopathy and underwent 18F-FDG DTPI as part of the evaluation for enhancing spinal cord lesions of unknown etiology for 2 years at a university-based cancer hospital. 18F-FDG DTPI was vital in making the diagnosis of sarcoidosis, and in two of the cases, the patients were able to avoid biopsy, thereby avoiding potential morbidity from an invasive procedure.
Conclusion. 18F-FDG PET/CT imaging is a noninvasive imaging technique that can be crucial in the diagnosis of sarcoidosis of the spinal cord and help avoid unnecessary procedures.
Level of Evidence: 4

The Role of Cross-Links in Posterior Spinal Fusion for Cerebral Palsy–Related Scoliosis

01-11-2019 – Usmani, M. Farooq; Shah, Suken A.; Yaszay, Burt; Samdani, Amer F.; Cahill, Patrick J.; Newton, Peter O.; Marks, Michelle C.; Sponseller, Paul D.

Study Design. Retrospective review of a multicenter, prospective database.
Objective. Our aim was to compare complication rates and maintenance of radiographic correction at 2 years after posterior spinal fusion (PSF) with or without cross-links in patients with cerebral palsy (CP)–related scoliosis.
Summary of Background Data. Cross-links are frequently used in PSF to correct scoliosis in patients with CP because they are thought to increase the stiffness and torsional rigidity of the construct.
Methods. We reviewed the records of patients with CP who underwent primary PSF with or without cross-links between August 2008 and April 2015. Inclusion criteria were minimum follow-up of 2 years, availability of complications data (implant failure, surgical site infection, revision), and pre- and postoperative measurements of the major curve (measured using the Cobb method). The 256 patients included in this analysis had a mean age of 14.1 ± 2.7 years. Ninety-four patients had cross-links (57% using one cross-link; 43% using two cross-links) and 162 patients did not have cross-links. P 0.05). Complication rates were similar between the cross-link group (16%, N = 15) and the non–cross-link group (14%, N = 22).
Conclusion. At 2 years after PSF to treat CP-related scoliosis, patients had no significant differences in the degree of correction achieved, the maintenance of correction, or the rate of complications between those whose fusion constructs used cross-links and those whose constructs did not.
Level of Evidence: 3

Muscle-evoked Potentials After Electrical Stimulation to the Brain in Patients Undergoing Spinal Surgery are Less Affected by Anesthetic Fade With Constant-voltage Stimulation Than With Constant-current Stimulation

01-11-2019 – Tanaka, Masato; Shigematsu, Hideki; Kawaguchi, Masahiko; Hayashi, Hironobu; Takatani, Tsunenori; Iwata, Eiichiro; Okuda, Akinori; Morimoto, Yasuhiko; Kawasaki, Sachiko; Masuda, Keisuke; Yamamoto, Yusuke; Tanaka, Yasuhito

Journal Article

Study Design. A prospective, within-subject study was conducted.
Objective. We aimed to compare the influence of anesthetic fade under maximum stimulation conditions between constant-current and constant-voltage stimulation techniques.
Summary of Background Data. The monitoring of muscle-evoked potentials after electrical stimulation to the brain Br(E)-MSEP) is useful for assessing the integrity of spinal cord motor tracts during major spine surgery. Nonetheless, Br(E)-MSEP responses are known to deteriorate over the duration of surgeries performed under general anesthesia. This phenomenon is known as anesthetic fade.
Methods. We recruited 117 patients undergoing various spinal surgeries from the cervical to the lumbar level. We excluded 29 cases with insufficient data. The decrease rate of the Br(E)-MSEP amplitude for each muscle was examined. Br(E)-MSEP monitoring with constant-current and constant-voltage stimulations at the C3 and C4 electrode positions was applied. Compound muscle action potentials (CMAPs) were bilaterally recorded from the abductor pollicis brevis, deltoid, abductor hallucis, tibialis anterior, gastrocnemius, and quadriceps muscles. We defined the decrease rate as follows: (initial CMAPs-final CMAPs)/initial CMAPs × 100. Differences in the decrease rate were evaluated between stimulators, limbs (upper vs. lower), and operative time group (lowest quartile vs. highest quartile).
Results. The overall decrease rate (across all muscles) increased as the operative time increased, and the rate was higher in the lower limbs than in the upper limbs. In addition, the overall decrease rate was lower with constant-voltage stimulation than with constant-current stimulation. Furthermore, the decrease rate for constant-current stimulation was significantly higher than that for constant-voltage stimulation, regardless of the operative time.
Conclusion. The CMAP waveform with constant-voltage stimulation is less susceptible to anesthetic fade than that with constant-current stimulation, even during long surgeries.
Level of Evidence: 3

Eating Behavior Traits, Weight Loss Attempts, and Vertebral Dimensions Among the General Northern Finnish Population

01-11-2019 – Oura, Petteri; Niinimäki, Jaakko; Karppinen, Jaro; Nurkkala, Marjukka

Journal Article

Study Design. A population-based birth cohort study.
Objective. To evaluate the associations of eating behavior traits and weight loss attempts with vertebral size among the general Northern Finnish population.
Summary of Background Data. Vertebral fragility fractures are a typical manifestation of osteoporosis, and small vertebral dimensions are a well-established risk factor for vertebral fracturing. Previous studies have associated cognitive eating restraint and diet-induced weight loss with deteriorated bone quality at various skeletal sites, but data on vertebral geometry are lacking.
Methods. This study of 1338 middle-aged Northern Finns evaluated the associations of eating behavior traits (flexible and rigid cognitive restraint of eating, uncontrolled eating, emotional eating; assessed by the Three-Factor Eating Questionnaire-18) and weight loss attempts (assessed by a separate questionnaire item) with magnetic resonance imaging-derived vertebral cross-sectional area (CSA). Sex-stratified linear regression models were used to analyze the data, taking body mass index, leisure-time physical activity, general diet, smoking, and socioeconomic status as potential confounders.
Results. Women with rigid or rigid-and-flexible cognitive eating restraints had 3.2% to 3.4% smaller vertebral CSA than those with no cognitive restraint (P ≤ 0.05). Similarly, the women who reported multiple weight loss attempts in adulthood and midlife had 3.5% smaller vertebral size than those who did not (P = 0.03). Other consistent findings were not obtained from either sex.
Conclusion. Rigid cognitive eating restraint and multiple weight loss attempts predict small vertebral size and thus decreased spinal health among middle-aged women, but not among men. Future longitudinal studies should confirm these findings.
Level of Evidence: 3

Cost-effectiveness of Operative versus Nonoperative Treatment of Adult Symptomatic Lumbar Scoliosis an Intent-to-treat Analysis at 5-year Follow-up

01-11-2019 – Carreon, Leah Y.; Glassman, Steven D.; Lurie, Jon; Shaffrey, Christopher I.; Kelly, Michael P.; Baldus, Christine R.; Bratcher, Kelly R.; Crawford, Charles H.; Yanik, Elizabeth L.; Bridwell, Keith H.

Journal Article

Study Design. Secondary analysis using data from the NIH-sponsored study on adult symptomatic lumbar scoliosis (ASLS) that included randomized and observational arms.
Objective. The aim of this study was to perform an intent-to-treat cost-effectiveness study comparing operative (Op) versus nonoperative (Non
Op) care for ASLS.
Summary of Background Data. The appropriate treatment approach for ASLS continues to be ill-defined. Non
Op care has not been shown to improve outcomes. Surgical treatment has been shown to improve outcomes, but is costly with high revision rates.
Methods. Patients with at least 5-year follow-up data were included. Data collected every 3 months included use of Non
Op modalities, medications, and employment status. Costs for index and revision surgeries and Non
Op modalities were determined using Medicare Allowable rates. Medication costs were determined using the Red
Book and indirect costs were calculated based on reported employment status and income. Qualityadjusted life year (QALY) was determined using the SF6D.
Results. There were 81 of 95 cases in the Op and 81 of 95 in the Non
Op group with complete 5-year follow-up data. Not all patients were eligible 5-year follow-up at the time of the analysis. All patients in the Op and 24 (30%) in the Non
Op group had surgery by 5 years. At 5 years, the cumulative cost for Op was $96,000 with a QALY gain of 2.44 and for Non
Op the cumulative cost was $49,546 with a QALY gain of 0.75 with an incremental cost-effectiveness ratio (ICER) of $27,480 per QALY gain.
Conclusion. In an intent-to-treat analysis, neither treatment was dominant, as the greater gains in QALY in the surgery group come at a greater cost. The ICER for Op compared to Non
Op treatment was above the threshold generally considered cost-effective in the first 3 years of the study but improved over time and was highly cost-effective at 4 and 5 years.
Level of Evidence: 2

Responsiveness of EQ-5D Youth version 5-level (EQ-5D-5L-Y) and 3-level (EQ-5D-3L-Y) in Patients With Idiopathic Scoliosis

01-11-2019 – Wong, Carlos King Ho; Cheung, Prudence Wing Hang; Luo, Nan; Lin, Jiaer; Cheung, Jason Pui Yin

Study Design. Prospective cohort study
Objective. The aim of this study was to evaluate the responsiveness of EQ-5D Youth version (EQ-5D-Y) 5-level and 3-level in patients with idiopathic scoliosis
Summary of Background Data. A new version of EQ-5D-Y increasing the number of response levels from 3 (3LY) to 5 (5LY) has been recently introduced. Although the validity and reliability of 5LY and 3LY for use in idiopathic scoliosis patients are compared, responsiveness of two questionnaires among children and adolescents is unknown.
Methods. A total of 129 children or adolescents attending the spine clinics of a tertiary hospital in Hong Kong, China, completed 3LY and 5LY. At 3-month follow-up, 110 (85.2%) patients completed two EQ-5D-Y questionnaires, and the single-item Global Rating on Change Scale determining “worsened,”, “unchanged,”, or “improved” global health. Among those indicating “unchanged” in global health from baseline to follow-up, agreement in responses to each 3LY and 5LY item was examined. Mean changes in EQ-5D-Y scores during the past 3 months in patients with “worsened,” “unchanged,” and “improved” health were calculated.
Results. Most patients (82.7%) reported no change in global health, whereas about 12.7% and 4.5% of them felt better and worse, respectively, compared to baseline. Among those reporting “unchanged health,” the “Looking after myself” item exhibited the largest proportion of agreement in responses (5LY: 96.36%; 3LY: 95.50%), followed by “Mobility” (5LY 90.91%; 3LY 90.99%), “Usual activities” (5LY 83.64%; 3LY 87.39%), “Pain/discomfort”(5LY 68.18%; 3LY 76.58%), and “Feeling worried/sad/unhappy” (5LY 66.36%; 3LY 72.07%). In the “improved” or “worsened” group, the 3-month follow-up 5LY and 3LY scores were higher or lower compared with baseline, respectively.
Conclusion. The 5LY is demonstrated as responsive as the 3LY for patients with idiopathic scoliosis.
Level of Evidence: 2

Admission NarxCare Narcotics Scores are not Associated With Adverse Surgical Outcomes or Self-reported Patient Satisfaction Following Elective Spine Surgery

01-11-2019 – Galivanche, Anoop R.; Mercier, Michael R.; Adrados, Murillo; Pathak, Neil; McLynn, Ryan P.; Anandasivam, Nidharshan S.; Varthi, Arya G.; Rubin, Lee E.; Grauer, Jonathan N.

Journal Article

Study Design. Retrospective cohort study
Objective. The aim of this study was to investigate how elective spine surgery patient preoperative opioid use (as determined by admission Narx
Care narcotics use scores) correlated with 30-day perioperative outcomes and postoperative patient satisfaction.
Summary of Background Data. The effect of preoperative narcotics usage on postoperative outcomes and patient satisfaction following spine surgery has been of question. The Narx
Care platform analyzes the patients’ state Physician Drug Monitoring Program (PDMP) records to assign numerical scores that approximate a patients overall opioid drug usage.
Methods. Elective spine surgery cases performed at a single institution between October 2017 and March 2018 were evaluated. Narx
Care narcotics use scores at the time of admission were assessed. Patient characteristics, as well as 30-day adverse events, readmissions, reoperations, and mortality, were abstracted from the medical record. Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey data were also abstracted when available.
Cases were binned based on the following ranges of admission Narx
Care scores: 0, 1 to 99, 100 to 299, 300 to 499, and 500+. Multivariate logistic regressions were performed to compare the odds of having an adverse events, readmission, reoperation, and mortality between the different narcotics groups. One-way analysis of variance analyses were performed to compare HCAHPS survey response rates and HCAHPS survey results between the different narcotics score groups.
Results. In total, 346 patients met criteria for inclusion in the study (Narx
Score 0: n = 74, 1–99: n = 58, 300–499: n = 117, and 500+: n = 21). Multivariate logistic regressions did not detect statistically significant differential odds of experiencing adverse events, readmission, reoperation, or mortality between the different groups of admissions narcotics scores. Analyses of variance did not detect statistically significant differences in HCAHPS survey response rates, total HCAHPS scores, or HCAHP subgroup scores between the different narcotics score groups.
Conclusion. Although there are many reasons to address preoperative patient narcotic utilization, the present study did not detect perioperative outcome differences or patient satisfaction based on the narcotic use scores as stratified here.
Level of Evidence: 3

Conventional Versus Stereotactic Image-guided Pedicle Screw Placement During Posterior Lumbar Fusions: A Retrospective Propensity Score-matched Study of a National Longitudinal Database

01-11-2019 – Pendharkar, Arjun V.; Rezaii, Paymon G.; Ho, Allen L.; Sussman, Eric S.; Veeravagu, Anand; Ratliff, John K.; Desai, Atman M.

Study Design. Retrospective 1:1 propensity score-matched analysis on a national longitudinal database between 2007 and 2016.
Objective. The aim of this study was to compare complication rates, revision rates, and payment differences between navigated and conventional posterior lumbar fusion (PLF) procedures with instrumentation.
Summary of Background Data. Stereotactic navigation techniques for spinal instrumentation have been widely demonstrated to improve screw placement accuracies and decrease perforation rates when compared to conventional fluoroscopic and free-hand techniques. However, the clinical utility of navigation for instrumented PLF remains controversial.
Methods. Patients who underwent elective laminectomy and instrumented PLF were stratified into “single level” and “3- to 6-level” cohorts. Navigation and conventional groups within each cohort were balanced using 1:1 propensity score matching, resulting in 1786 navigated and conventional patients in the single-level cohort and 2060 in the 3 to 6 level cohort. Outcomes were compared using bivariate analysis.
Results. For the single-level cohort, there were no significant differences in rates of complications, readmissions, revisions, and length of stay between the navigation and conventional groups. For the 3- to 6-level cohort, length of stay was significantly longer in the navigation group (P < 0.0001). Rates of readmissions were, however, greater for the conventional group (30-day: P = 0.0239; 90-day: P = 0.0449). Overall complications were also greater for the conventional group (P = 0.0338), whereas revision rate was not significantly different between the 2 groups. Total payments were significantly greater for the navigation group in both the single level and 3- to 6-level cohorts (P < 0.0001).
Conclusion. Although use of navigation for 3- to 6-level instrumented PLF was associated with increased length of stay and payments, the concurrent decreased overall complication and readmission rates alluded to its potential clinical utility. However, for single-level instrumented PLF, no differences in outcomes were found between groups, suggesting that the value in navigation may lie in more complex procedures.
Level of Evidence: 3

Propensity-matched Comparison of Outcomes and Costs After Macroscopic and Microscopic Anterior Cervical Corpectomy Using a National Longitudinal Database

01-11-2019 – Ho, Allen Lin; Rezaii, Paymon Garakani; Pendharkar, Arjun Vivek; Sussman, Eric Scott; Veeravagu, Anand; Ratliff, John Kevin; Desai, Atman Mukesh

Study Design. A retrospective analysis of national longitudinal database.
Objective. The aim of this study was to examine the outcomes and cost-effectiveness of operating microscope utilization in anterior cervical corpectomy (ACC).
Summary of Background Data. The operating microscope allows for superior visualization and facilitates ACC with less manipulation of tissue and improved decompression of neural elements. However, many groups report no difference in outcomes with increased cost associated with microscope utilization.
Methods. A longitudinal database (Market
Scan) was utilized to identify patients undergoing ACC with or without microscope between 2007 and 2016. Propensity matching was performed to normalize differences between the two cohorts. Outcomes and costs were subsequently compared.
Results. A total of 11,590 patients were identified for the “macroscopic” group, while 4299 patients were identified for the “microscopic” group. For the propensity-matched analysis, 4298 patients in either cohort were successfully matched according to preoperative characteristics. Hospital length of stay was found to be significantly longer in the macroscopic group than the microscopic group (1.86 nights vs. 1.56 nights, P < 0.0001). Macroscopic ACC patients had an overall higher rate of readmissions 30-day: 4.2% vs. 3.2%, odds ratio (OR) = 0.76 (0.61–0.96), P = 0.0223; 90-day: 7.0% vs. 5.9%, OR = 0.82 (0.69–0.98), P = 0.0223. Microscopic ACC patients had a higher rate of discharge to home 86.6% vs. 92.5%, OR = 1.91 (1.65–2.21), P < 0.0001 and lower rates of new referrals to pain management 1.0% vs. 0.4%, OR = 0.42 (0.23–0.74), P = 0.0018 compared with macroscopic ACC. Postoperative complication rate was not found to be significantly different between the groups. Finally, total initial admission charges were not significantly different between the macroscopic and microscopic groups ($30,175 vs. $29,827, P = 0.9880).
Conclusion. The present study suggests that the use of the operating microscope for ACC is associated with decreased length of stay, readmissions, and new referrals to pain management, as well as higher rate of discharge to home.
Level of Evidence: 3

Degenerative Disc Disease: What is in a Name?

01-11-2019 – Battié, Michele C.; Joshi, Anand B.; Gibbons, Laura E.; the ISSLS Degenerative Spinal Phenotypes Group

Journal Article

Study Design. A systematic search and review
Objective. The aim of this study was to investigate the term, degenerative disc disease, to elucidate its current usage and inform clinical, research, and policy recommendations.
Summary of Background Data. Degenerative disc disease has long been a dominant concept in common, painful spinal disorders. Yet, despite its pervasiveness and important clinical consequences and controversies, there has not been a systematic examination of its use and meaning in the scientific literature.
Methods. We conducted a systematic search of publications using the term degenerative disc disease from 2007 through 2016 in Ovid MEDLINE (R), Embase, CINAHL, and Scopus. Two investigators independently reviewed all publications in the primary sample. Publication and author identifiers, and qualitative study descriptors were extracted. Finally, the definition of degenerative disc disease was placed in one of eight categories. Data were summarized using descriptive statistics.
Results. Degenerative disc disease appeared in the titles of 402 publications in the primary sample and increased in frequency by 189% from the first to the last 3 years of the decade. No single definition was used in the majority of publications, and most frequently, the term was used without any definition provided (30.1%). In other cases, degenerative disc disease specifically included radiculopathy or myelopathy (14.4%), or only back or neck pain (5.5%), or was equated with disc degeneration regardless of the presence of symptoms (15.4%), or with discogenic pain or disc degeneration as a presumed cause of axial pain (12.7%). Another 7.2% comprised a mix of broad ranging findings and diagnoses. The most notable differences in definitions occurred between surgeons and other disciplines, and when applied to cervical versus lumbar regions.
Conclusion. Despite longstanding use and important consequences, degenerative disc disease represents an underdeveloped concept, with greatly varying, disparate definitions documented. Such inconsistencies challenge clear, accurate communication in medicine and science, create confusion and misconceptions among clinicians, patients and others, and hinder the advancement of related knowledge.
Level of Evidence: 4

In Degenerative Spondylolisthesis, Unilateral Laminotomy for Bilateral Decompression Leads to Less Reoperations at 5 Years When Compared to Posterior Decompression With Instrumented Fusion: A Propensity-matched Retrospective Analysis

01-11-2019 – Kuo, Calvin C.; Merchant, Maqdooda; Kardile, Mayur P.; Yacob, Alem; Majid, Kamran; Bains, Ravinder S.

Journal Article

Study Design. Multicenter retrospective cohort study.
Objective. The aim of this study was to compare reoperation rates at 5-year follow-up of unilateral laminotomy for bilateral decompression (ULBD) versus posterior decompression with instrumented fusion (Fusion) for patients with low-grade degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) in a multicenter database.
Summary of Background Data. Controversy exists regarding whether fusion should be used to augment decompression surgery in patients with LSS with DS. For years, the standard has been fusion with standard laminectomy to prevent postoperative instability. However, this strategy is not supported by Level 1 evidence. Instability and reoperations may be reduced or prevented using less invasive decompression techniques.
Methods. We identified 164 patients with DS and LSS who underwent ULBD between January 2007 and December 2011 in a multicenter database. These patients were propensity score-matched on age, sex, race, and smoking status with patients who underwent Fusion (n = 437). Each patient required a minimum of 5-year follow-up. The primary outcome was 5-year reoperation. Secondary outcome measures included postoperative complication rates, blood loss during surgery, and length of stay. Logistic regression models were used to estimate the odds ratio of the 5-year reoperation rate between the two surgical groups.
Results. The reoperation rate at 5-year follow-up was 10.4% in the ULBD group and 17.2% in the Fusion group. ULBD reoperations were more frequent at the index surgical level; Fusion reoperations were more common at an adjacent level. The two types of operations had similar postoperative complication rates, and both groups tended to have fusion reoperations.
Conclusion. For patients with stable DS and LSS, ULBD is a viable, durable option compared to fusion with decreased blood loss and length stay, as well as a lower reoperation rate at 5-year follow-up. Further prospective studies are required to determine the optimal clinical scenario for ULBD in the setting of DS.
Level of Evidence: 3

TO THE EDITOR:

01-11-2019 – Kang, Chang-Nam; Heo, Dong Ryul; Choi, Sung Hoon

Journal Article

No abstract available