Spine

Spine

“Guanhai Resort of HaiYan, JiaXing, Zhejiang Province, China”

01-09-2019 –

No abstract available

The Role of Type I Diabetes in Intervertebral Disc Degeneration

01-09-2019 – Russo, Fabrizio; Ambrosio, Luca; Ngo, Kevin; Vadalà, Gianluca; Denaro, Vincenzo; Fan, Yong; Sowa, Gwendolyn; Kang, James D.; Vo, Nam

Journal Article

Study Design. An experimental laboratory study.
Objective. To investigate the pathogenesis of intervertebral disc degeneration (IDD) in a murine model of type 1 diabetes mellitus (DM), namely nonobese diabetic (NOD) mouse.
Summary of Background Data. IDD is a leading contributor of low back pain, which represents one of the most disabling symptoms within the adult population. DM is a chronic metabolic disease currently affecting one in 10 adults in the United States. It is associated with an increased risk of developing IDD, but the underlying process remains poorly understood.
Methods. Total disc glycosaminoglycan content, proteoglycan synthesis, aggrecan fragmentation, glucose transporter gene expression, and apoptosis were assessed in NOD mice and wild-type euglycemic control mice. Spinal structural and molecular changes were analyzed by micro-computed tomography, histological staining (Safranin-O and fast green), and quantitative immunofluorescence (anti-ADAMTS-4 and -5 antibodies).
Results. Compared with euglycemic controls, NOD mice showed increased disc apoptosis and matrix aggrecan fragmentation. Disc glycosaminoglycan content and histological features of NOD mice did not significantly differ from those of euglycemic littermates.
Conclusion. These data demonstrate that DM may contribute to IDD by increasing aggrecan degradation and promoting cell apoptosis, which may represent early indicators of the involvement of DM in the pathogenesis of IDD.
Level of Evidence: N/A

Transport of Vancomycin and Cefepime Into Human Intervertebral Discs: Quantitative Analyses

01-09-2019 – Zhu, Qiaoqiao; Gao, Xin; Brown, Mark D.; Eismont, Frank; Gu, Weiyong

Journal Article

Study Design. Simulation of antibiotics transport into human intervertebral disc with intravenous infusion.
Objective. The objective of this study was to quantitatively investigate antibiotic concentrations in the disc.
Summary of Background Data. Intravenous infusion of antibiotics is typically used to treat intervertebral disc infection in clinics. However, it is difficult to evaluate the drug concentrations within discs in vivo.
Methods. A computational model was used in this study. The variation of drug charge with p
H was considered in the model. Thirty-minute infusions of two commonly used antibiotics in clinic—vancomycin and cefepime—were numerically investigated. Spatial and temporal concentration distributions of these drugs in both nondegenerated and moderately degenerated discs were calculated.
Results. For intravenous infusion of 1 g vancomycin and 2 g cefepime in 30 minutes repeated every 12 hours, it was predicted that vancomycin concentration in the disc fluctuated between 17.0 and 31.0 times of its minimum inhibitory concentration (1 ug/m
L) and cefepime concentration fluctuated between 1.1 and 4.2 times of its minimum inhibitory concentration (i.e., 8 ug/m
L) in about 2 days. It was also found that vancomycin concentration in moderately degenerated disc was lower than that in the nondegenerated disc.
Conclusion. This study provides quantitative guidance on selecting proper dosage for treating disc infection. The method used in this study could be used to provide quantitative information on transport of other antibiotics and drugs in discs as well.
Level of Evidence: N/A

Endothelin-1 Activates the Notch Signaling Pathway and Promotes Tumorigenesis in Giant Cell Tumor of the Spine

01-09-2019 – Yuan, Wei; Qian, Ming; Li, Zhen-Xi; Zhao, Cheng-Long; Zhao, Jian; Xiao, Jian-Ru

Journal Article

Study Design. Experimental study.
Objective. To examine the role of endothelin-1 (ET-1) and the Notch signaling pathway in giant cell tumor (GCT) of the spine.
Summary of Background Data. Previously published studies have shown that the Notch signaling pathway has a role in tumor invasion and that ET-1 is involved in tumor invasion and angiogenesis. However, the roles of both Notch signaling and ET-1 in GCT of the spine remain unknown.
Methods. Expression of ET-1 in tissue samples from patients with spinal GCT, and adjacent normal tissue, were analyzed by immunohistochemistry and western blot. GCT stromal cells (GCTSCs) were isolated and ET-1 expression was demonstrated by immunofluorescence. Cell viability and cell migration of GCTSCs and human vascular endothelial cells following ET-1 treatment were assessed using the cell counting kit-8 assay and a transwell assay. Receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) m
RNA expression was determined following ET-1 treatment of GCTSCs using quantitative real-time polymerase chain reaction. In GCTSCs treated with ET-1 and the ET-1 signaling antagonist, BQ-123, levels of cyclin D1, vascular endothelial growth factor, matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9), Jagged1, Hes1, Hey2, and Notch intracellular domain were examined by western blot.
Results. Compared with normal adjacent tissue, ET-1 was highly expressed in GCT tissue. In GCTSCs studied in vitro, treatment with ET-1 significantly increased GCTSC and human vascular endothelial cells growth and migration and increased the expression of RANKL and OPG, meanwhile the ratio of RANKL/OPG was increased, in GCTSCs, it upregulated the production of cyclin D1, vascular endothelial growth factor, MMP-2, MMP-9, Jagged1, Hes1, Hey2, and Notch intracellular domain expression in a dose-dependent manner. Treatment with BQ-123 reversed these effects.
Conclusion. In GCT of the spine, ET-1 showed increased expression. In cultured GCTSCs, ET-1 treatment activated the Notch signaling pathway.
Level of Evidence: 2

Anterior Atlantooccipital Transarticular Screw Fixation: A Cadaveric Study and Description of a Novel Technique

01-09-2019 – Ji, Wei; Xu, Xiaolin; Liu, Qi; Lin, Junyu; Huang, Zucheng; Chen, Jianting; Zhu, Qingan

Journal Article

Study Design. Retrospective analysis of collected data and operative experiment on human cadavers.
Objective. To describe a novel technique of the anterior atlantooccipital (AC) transarticular screw fixation, and to analyze the pertinent anatomy with cadaveric and radiographic assessment of the feasibility, safety, and general applicability of this technique.
Summary of Background Data. In some situations, the posterior AC fixation techniques may not be possible, or may require supplemental fixation, which include the congenital hypoplasia, absence of the bony elements, and even revision surgery. However, an anterior screw fixation technique may add stability to further attempts at obtaining an arthrodesis.
Methods. A detailed description of the surgical technique was presented. Three-dimensional (3D) CT reconstruction of the cranioverteral region of 30 patients were performed to determine screw entry points, target points, and proposed screw trajectories. Following screw insertion in eight fresh frozen human cadaver spine specimens, dissection verified screw location relative to structures at risk.
Results. The ideal entry point is located caudal to the C1 superior facet joint in line with the medial third of the C1 superior facet. The ideal screw is directed 41.7° posteriorly in the sagittal plane and 11.6° laterally in the coronal plane with a length around 30.4 mm. The feasibility of anterior AC screw fixation was 92% (35/38 cases). There is a risk of injury to the vertebral artery and the hypoglossal nerve.
Conclusion. Anterior AC transarticular screw fixation is feasible and can be considered as a salvage technique or an alternative for the posterior AC fixation, as well as the supplement to the anterior occipitocervical fixation.
Level of Evidence: 3

Short-term Outcomes Following Cervical Laminoplasty and Decompression and Fusion With Instrumentation

01-09-2019 – Boniello, Anthony; Petrucelli, Philip; Kerbel, Yudi; Horn, Samantha; Bortz, Cole A.; Brown, Avery E.; Pierce, Katherine E.; Alas, Haddy; Khalsa, Amrit; Passias, Peter

Journal Article

Study Design. Retrospective review of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database years 2010 to 2015.
Objective. Investigate which short-term outcomes differ for cervical laminoplasty and laminectomy and fusion surgeries.
Summary of Background Data. Conflicting reports exist in spine literature regarding short-term outcomes following cervical laminoplasty and posterior laminectomy and fusion. The objective of this study was to compare the 30-day outcomes for these two treatment groups for multilevel cervical pathology.
Methods. Patients who underwent cervical laminoplasty or posterior laminectomy and fusion were identified in National Surgical Quality Improvement Program (NSQIP) based on Current Procedural Terminology (CPT) code: laminoplasty 63,050 and 63,051, posterior cervical laminectomy 63,015 and 63,045, and instrumentation 22,842. Propensity-adjusted multivariate regressions assessed differences in postoperative length of stay, adverse events, discharge disposition, and readmission.
Results. Three thousand seven hundred ninety-six patients were included: 2397 (63%) underwent cervical laminectomy and fusion and 1399 (37%) underwent cervical laminoplasty. Both groups were similar in age, sex, body mass index (BMI), American Society of Anesthesiologist Classification (ASA), Charleston Comorbidity Index (CCI), and had similar rates of malnutrition, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, and history for steroid use. Age more than 70 and age less than 50 were not associated with one treatment group over the other (P > 0.05). Compared with laminoplasty patients, laminectomy and fusion patients had increased lengths of stay (LOS) (4.5 vs. 3.7 d, P  0.05 for all).
Conclusion. Posterior cervical laminectomy and fusion patients were found to have increased LOS, readmissions, and complications despite having similar pre-op demographics and comorbidities. Patients and surgeons should consider these risks when considering surgical treatment for cervical pathology.
Level of Evidence: 3

Modic Changes Are Not Associated With Long-term Pain and Disability: A Cohort Study With 13-year Follow-up

01-09-2019 – Udby, Peter Muhareb; Bendix, Tom; Ohrt-Nissen, Søren; Lassen, Michael Ruud; Sørensen, Joan Solgaard; Brorson, Stig; Carreon, Leah Y.; Andersen, Mikkel Østerheden

Journal Article

Study Design. A comparative cohort study with 13-year follow-up.
Objective. To assess whether Modic changes (MCs) are associated with long-term physical disability, back pain, and sick leave.
Summary of Background Data. Previous studies have shown a conflicting association of low back pain (LBP) with MCs and disc degeneration. The long-term prognosis of patients with MCs is unclear.
Methods. In 2004 to 2005, patients aged 18 to 60 with daily LBP were enrolled in an randomized controlled trial study and lumbar magnetic resonance imaging (MRI) was performed. Patients completed numeric rating scales (0–10) for LBP and leg pain, Roland-Morris Disability Questionnaire (RMDQ), LBP Rating Scale for activity limitations (RS, 0–30), inflammatory pain pattern and sick leave days due to LBP at baseline and 13 years after the MRI. Patients were stratified based on the presence (+MC) or absence (−MC) of MCs on the MRI.
Results. Of 204 cases with baseline MRI, 170 (83%) were available for follow-up; 67 (39%) with MCs and 103 (61%) without MCs. Demographics, smoking status, BMI, use of antibiotics, LBP, leg pain, and inflammatory pain pattern scores at baseline and at 13-year follow-up were similar between the two groups. Also, baseline RMDQ was similar between the +MC and −MC groups. At 13 years, the RMDQ score was statistically significant better in the +MC group (7.4) compared with the −MC group (9.6, P = 0.024). Sick leave days due to LBP were similar at baseline but less in the +MC group (9.0) compared with the −MC group (22.9 d, P = 0.003) at 13 years.
Conclusion. MCs were not found to be negatively associated with long-term pain, disability, or sick leave. Rather, the study found that LBP patients with MCs had significantly less disability and sick-leave at long-term follow-up. We encourage further studies to elucidate these findings.
Level of Evidence: 2

Sacropelvic Fixation With S2 Alar Iliac Screws May Prevent Sacroiliac Joint Pain After Multisegment Spinal Fusion

01-09-2019 – Unoki, Eiki; Miyakoshi, Naohisa; Abe, Eiji; Kobayashi, Takashi; Abe, Toshiki; Kudo, Daisuke; Shimada, Yoichi

Journal Article

Study Design. A retrospective study.
Objective. To examine the postoperative incidence of sacroiliac joint pain (SIJP) at the lower fusion level following multisegment fusion.
Summary of Background Data. Recently, multisegment fusion is being increasingly performed. While proximal junctional kyphosis (PJK) commonly develops following multisegment fusion, SIJP also commonly occurs following this surgery. In surgery for adult spinal deformity, fixation is often extended to the pelvis to include the sacroiliac joint. Therefore, the question of whether SIJP occurs in such cases is interesting. Here, we examined postoperative incidence of SIJP at the lower fusion level, including the incidence of PJK, and postoperative lumbopelvic alignment.
Methods. Participants included 77 patients who underwent corrective fusion (≥3 segments). Patients were divided into three groups based on the lower fixation end: L5 (L5), S (sacrum), and P (pelvis). In the P group, an S2 alar iliac screw was used. Postoperative incidence of SIJP and PJK in each group was examined along with lumbopelvic parameters.
Results. SIJP incidence was 16.7%, 26.1%, and 4.2% in the L5, S, and P groups, respectively, indicating the highest value in the S group and a significantly lower value in the P group. PJK incidence was 23.3%, 30.4%, and 29.2% in the L5, P, and S groups, respectively, with no significant differences. Regarding postoperative lumbopelvic parameters, there was no significant difference between the groups; however, lumbar lordosis tended to be better in the P group.
Conclusion. SIJP incidence was extremely high with fixation to the sacrum, and in the group with fixation to the pelvis, there was hardly any SIJP. Sacropelvic fixation using S2 alar iliac screws could prevent SIJP onset following multisegment fusion.
Level of Evidence: 3

Sagittal Alignment Profile Following Selective Thoracolumbar/Lumbar Fusion in Patients With Lenke Type 5C Adolescent Idiopathic Scoliosis

01-09-2019 – Tauchi, Ryoji; Kawakami, Noriaki; Ohara, Tetsuya; Saito, Toshiki; Tanabe, Hironori; Morishita, Kazuaki; Yamauchi, Ippei

Journal Article

Study Design. A retrospective case series.
Objective. This study aimed to report the sagittal outcome measures in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) undergoing thoracolumbar/lumbar (TL/L) fusion surgery.
Summary of Background Data. Previous studies have demonstrated coronal correction of Lenke type 5C AIS by selective TL/L fusion surgery. However, little is known about the sagittal influence of selective TL/L curve correction in Lenke type 5C AIS.
Methods. Thirty-nine patients with Lenke type 5C AIS underwent selective posterior TL/L curves fusion (mean age, 15.9 ± 2.1 yrs). Preoperative and postoperative radiographic and clinical parameters were analyzed at a minimum 2-year follow-up period. Radiographic parameters were compared between patients with Lenke sagittal modifier normal (Group N) to those with Lenke sagittal modifier minus (Group M).
Results. The main TL/L Cobb angle was 46.3° ± 7.7° preoperatively and 20.7° ± 5.3° (P < 0.0001) at 2-year follow-up. Also, thoracic kyphosis (TK) (T1–12) angle was 29.0° ± 11.3° preoperatively and 36.4° ± 10.3° at follow-up (P < 0.001), and TK (T5–12) angle was 18.1° ± 10.2° preoperatively and 25.9° ± 8.9° at follow-up (P < 0.001). The cervical lordosis (CL) was 9.6° ± 11.6° preoperatively and 6.1° ± 10.9° at follow-up (P = 0.037). Compared with the Lenke sagittal modifier groups, preoperative TK (T1–12), TK (T5–12), thoracolumbar kyphosis (TLK), and CL were significantly different from both the groups; and after the surgery, no significant differences in these parameters were observed between the two groups.
Conclusion. After the selective TL/L posterior fusion surgery in patients with Lenke type 5C AIS, the sagittal alignment profile, including TK, TLK, C7 sagittal vertical axis, T1 slope, and CL, was significantly changed. With regard to the sagittal aspect, selective TL/L surgery was more likely to affect Group M than Group N.
Level of Evidence: 4

Magnetically Controlled Growing Rods in Treatment of Early-Onset Scoliosis: A Single Center Study With a Minimum of 2-Year-Follow up and Preliminary Results After Converting Surgery

01-09-2019 – Lampe, Lukas Peter; Schulze Bövingloh, Albert; Gosheger, Georg; Schulte, Tobias L.; Lange, Tobias

Journal Article

Study Design. Case series.
Objective. To evaluate complications and radiographic parameters after magnetically controlled growing rod (MCGR) index surgery (IS), during lengthening and following converting surgery (CS) with a minimum of 2-year follow up (FU).
Summary of Background Data. MCGR are maintaining skeletal growth in treatment of early onset scoliosis (EOS). There is no data regarding correction potential after CS available.
Methods. Twenty-four cases were included. Two patients with rib and pelvic hook fixation instead of pedicle screws and three patients with previous spinal surgery were excluded from radiographic analysis.
Results. Twenty-one patients received grade 3 or 4 in Classification of Early-Onset-Scoliosis (C-EOS) for main curve severity. The kyphotic modifiers (–) were given to seven and (+) to seven patients. Mean age at IS was 10.5 ± 2.4 years with a mean FU time of 42.3 ± 11.3 months. Deformity correction was only achieved during IS (46%) and CS (36%). During MCGR treatment a 5° loss of correction seen, while 25 mm of T1–S1 length was gained during the lengthening period. An overall average lengthening of 1.6 mm per lengthening procedure was achieved. Possibility to gain length during distractions decreases over time. No major failure of the distraction mechanism was observed, only 16 lengthening procedures failed within a total of 264 lengthening procedures. A total of 19 revision surgeries in 10 patients were observed. Four patients received more than one revision surgery.
Conclusion. Applying MCGR results in a revision rate of 0.23 per patient and per one FU year, while making further lengthening procedures obsolete compared with conventional growing rod techniques. Correction of major curve is possible during IS und CS. The law of diminishing returns applies during the period of lengthening.
Level of Evidence: 4

Effect of Serious Adverse Events on Health-related Quality of Life Measures Following Surgery for Adult Symptomatic Lumbar Scoliosis

01-09-2019 – Smith, Justin S.; Shaffrey, Christopher I.; Kelly, Michael P.; Yanik, Elizabeth L.; Lurie, Jon D.; Baldus, Christine R.; Edwards, Charles; Glassman, Steven D.; Lenke, Lawrence G.; Boachie-Adjei, Oheneba; Buchowski, Jacob M.; Carreon, Leah Y.; Crawford, Charles H. III; Errico, Thomas J.; Lewis, Stephen J.; Koski, Tyler; Parent, Stefan; Kim, Han Jo; Ames, Christopher P.; Bess, Shay; Schwab, Frank J.; Bridwell, Keith H.

Journal Article

Study Design. Secondary analysis of prospective multicenter cohort.
Objective. To assess effect of serious adverse events (SAEs) on 2- and 4-year patient-reported outcomes measures (PROMs) in patients surgically treated for adult symptomatic lumbar scoliosis (ASLS).
Summary of Background Data. Operative treatment for ASLS can improve health-related quality of life, but has high rates of SAEs. How these SAEs effect health-related quality of life remain unclear.
Methods. The ASLS study assessed operative versus nonoperative ASLS treatment, with randomized and observational arms. Patients were 40- to 80-years-old with ASLS, defined as lumbar coronal Cobb ≥30° and Oswestry Disability Index (ODI) ≥20 or Scoliosis Research Society-22 (SRS-22) ≤4.0 in pain, function, and/or self-image domains. SRS-22 subscore and ODI were compared between operative patients with and without a related SAE and nonoperative patients using an as-treated analysis combining randomized and observational cohorts.
Results. Two hundred eighty-six patients were enrolled, and 2- and 4-year follow-up rates were 90% and 81%, respectively, although at the time of data extraction not all patients were eligible for 4-year follow-up. A total of 97 SAEs were reported among 173 operatively treated patients. The most common were implant failure/pseudarthrosis (n = 25), proximal junctional kyphosis/failure (n = 10), and minor motor deficit (n = 8). At 2 years patients with an SAE improved less than those without an SAE based on SRS-22 (0.52 vs. 0.79, P = 0.004) and ODI (−11.59 vs. −17.34, P = 0.021). These differences were maintained at 4-years for both SRS-22 (0.51 vs. 0.86, P = 0.001) and ODI (−10.73 vs. −16.69, P = 0.012). Despite this effect, patients sustaining an operative SAE had greater PROM improvement than nonoperative patients (P<0.001).
Conclusion. Patients affected by SAEs following surgery for ASLS had significantly less improvement of PROMs at 2- and 4-year follow-ups versus those without an SAE. Regardless of SAE occurrence, operatively treated patients had significantly greater improvement in PROMs than those treated nonoperatively.
Level of Evidence: 2

The Amount of Relative Curve Correction Is More Important Than Upper Instrumented Vertebra Selection for Ensuring Postoperative Shoulder Balance in Lenke Type 1 and Type 2 Adolescent Idiopathic Scoliosis

01-09-2019 – Sielatycki, John Alex; Cerpa, Meghan; Beauchamp, Eduardo C.; Shimizu, Takayoshi; Wei, Chao; Pongmanee, Suthipas; Wang, Hui; Xue, Rui; Zhou, Rongping; Liu, Xinchun; Yang, Jun; Suomao, Yuan; Lenke, Lawrence G.; Harms Study Group

Journal Article

Study Design. Retrospective review of a prospectively collected multicenter database.
Objective. To assess how “overcorrection” of the main thoracic curve without control of the proximal curve increases the risk for shoulder imbalance in Lenke type 1 Adolescent Idiopathic Scoliosis (AIS).
Summary of Background Data. Postop shoulder imbalance is a common complication following AIS surgery. It is thought that a more cephalad upper-instrumented vertebra (UIV) decreases the risk of shoulder imbalance in Lenke type 1 and 2 curves; however, this has not been proven.
Methods. Thirteen surgeons reviewed preop and 5-year postop clinical photos and PA radiographs of patients from a large multicenter database with Lenke type 1 and 2 AIS curves who were corrected with pedicle screw/rod constructs. Predictors of postop shoulder imbalance were identified by univariate analysis; multivariate analysis was done using the classification and regression tree method to identify independent drivers of shoulder imbalance.
Results. One hundred forty-five patients were reviewed. The UIV was T3-T5 in 87% of patients, with 8.9% instrumented up to T1 or T2. Fifty-two (36%) had shoulder imbalance at 5 years. On classification and regression tree analysis when the proximal thoracic (PT) Cobb angle was corrected more than 52%, 80% of the patients had balanced shoulders. Similarly, when the PT curve was corrected less than 52% and the main thoracic (MT) curve was corrected less than 54%, 87% were balanced. However, when the PT curve was corrected less than 52%, and the MT curve was corrected more than 54%, only 41% of patients had balanced shoulders (P = 0.05). This relationship was maintained regardless of the UIV level.
Conclusion. In Lenke type 1 and 2 AIS curves, significant correction of the main thoracic curve (>54%) with simultaneous “under-correction” (<52%) of the upper thoracic curve resulted in shoulder height imbalance in 59% of patients, regardless of the UIV. This suggests the PT curve must be carefully scrutinized in order to optimize shoulder balance, especially when larger correction of the MT curve is performed.
Level of Evidence: 2

Pedicle Stress Injury in Children and Adolescents With Low Back Pain

01-09-2019 – Ekin, Elif Evrim; Altunrende, Muhittin Emre

Journal Article

Study Design. A cross-sectional, retrospective cohort study.
Objective. To examine the prevalence of the pedicle stress injury, spondylolysis in children and adolescents with low back pain. And secondly, to test the hypothesis that these pathologies are associated with lumbar lordosis angle.
Summary of Background Data. The prevalence of the pedicle stress injury has not been investigated in children with low back pain. In recent studies, lumbar lordosis angle was associated with spondylolysis, on the other hand the pedicle stress injury was not investigated yet.
Methods. In this retrospective study, 789 consecutive lumbar magnetic resonance imaging under 18 years of age were reviewed between January 2015 and July 2018. Seven hundred magnetic resonances imaging among them were included in the study (mean age: 14.87 ± 2.41 yrs; range: 4–17). Prevalence of spondylolysis, spondylolisthesis, pedicle stress injury, pedicle deformation, disc degeneration, and increased lordosis was investigated and compared in terms of sex. The relationship between increased lordosis and other pathologies was evaluated with risk ratio. Nominal variables were evaluated between the two groups using chi-square, Mann–Whitney U test.
Results. Prevalence of pedicle stress injury (12.7%), spondylolysis (8.7%), spondylolisthesis (4.1%), pedicle deformation (3.1%), disc degeneration (24%), increase in lordosis (17.4%) was found. Spondylolysis and pedicle injury were more frequent in males (P = 0.025, P < 0.001, respectively). Increased lordosis was more frequent in females (P < 0.001). Pedicle stress injury was frequently observed between 13 to 17 years and often an isolated lesion (69.6%). Spondylolysis, spondylolisthesis, pedicle deformity were more frequent in increased lordosis (P < 0.001), whereas pedicle injury frequency was not found to be different (P = 0.997).
Conclusion. Pedicle stress injury is a common cause of back pain under 18 years of age, more common in males, and often an isolated lesion. No relationship was found between pedicle stress injury and increased lordosis, unlike other pathologies.
Level of Evidence: 3

Post-traumatic Stress Disorder Symptoms are Associated With Incident Chronic Back Pain: A Longitudinal Twin Study of Older Male Veterans

01-09-2019 – Suri, Pradeep; Boyko, Edward J.; Smith, Nicholas L.; Jarvik, Jeffrey G.; Jarvik, Gail P.; Williams, Frances M.K.; Williams, Rhonda; Haselkorn, Jodie; Goldberg, Jack

Journal Article

Study Design. A longitudinal cotwin control study of the Vietnam Era Twin Registry.
Objective. The aim of this study was to examine the association of post-traumatic stress disorder (PTSD) symptoms with incident chronic back pain (CBP), while controlling for genetic factors and early family environment.
Summary of Background Data. It is unknown whether PTSD symptoms are associated with an increased incidence of CBP.
Methods. In 2010 to 2012, a baseline survey was undertaken as part of a large-scale study of PTSD. Study participants completed the PTSD Symptom Checklist (PCL) and a self-report measure of CBP. In 2015 to 2017, a follow-up survey was sent to all 171 monozygotic (MZ) twin pairs (342 individuals) where both cotwins had no history of CBP at baseline, but only one cotwin in the pair met criteria for having current PTSD symptoms (one twin with PCL <30 and the cotwin with PCL ≥30). No other inclusion/exclusion criteria were applied. CBP at 5-year follow-up was defined as back pain of duration ≥3 months in the low back or mid/upper back. Covariates included age, race, education, income, Veterans Affairs health care use, disability compensation, smoking, body mass index, and depression. Statistical analysis estimated the cumulative incidence of CBP according to baseline PTSD symptoms. Risk ratios (RRs) and 95% confidence intervals (95% CIs) were estimated in matched-pair cotwin control analyses adjusting for familial factors.
Results. Among 227 males completing 5-year follow-up, including 91 MZ twin pairs, the mean age was 62 years. Five-year incidence of CBP in those without and with baseline PTSD symptoms was 40% and 60%, respectively. Baseline PTSD symptoms were significantly associated with incident CBP in crude and multivariable-adjusted within-pair analyses (RR 1.6, 95% CI 1.2–2.1; P = 0.002).
Conclusion. PTSD symptoms were associated with an increased incidence of CBP, without confounding by genetic factors or early family environment. PTSD symptoms may be a modifiable risk factor for prevention of CBP.
Level of Evidence: 3

Predictive Factors of Male Sexual Dysfunction After Traumatic Spinal Cord Injury

01-09-2019 – Ferro, Josepha Karinne de Oliveira; Lemos, Andrea; Silva, Caroline Palácio da; Lima, Claudia Regina Oliveira de Paiva; Raposo, Maria Cristina Falcão; Cavalcanti, Geraldo de Aguiar; Oliveira, Daniella Araújo de

Journal Article

Study Design. Observational study (Ethics Committee Number 973.648).
Objective. Evaluating the social and clinical factors associated with sexual dysfunction in men with traumatic spinal cord injury, as well as predictive factors for sexual dysfunction.
Summary of Background Data. Besides the motor and sensory loss, sexual function changes after spinal cord injury, ranging from decreased sexual desire to erectile disorders, orgasm, and ejaculation.
Methods. Performed with 45 men, with traumatic spinal cord injury and sexually active. Sexual function was assessed by the International Index of Erectile Function and the level and degree of injury were determined following guidelines of International Standards for Neurological and Functional Examination Classification of Spinal Cord Injury. Bi and multivariate analysis was applied, with a 0.05 significance level.
Results. Forty-five subjects with mean injury time of 7.5 years (CI 5.2–9.9) were evaluated. Having a fixed partner is a protective factor (OR: 0.25; 95% CI: 0.07–0.92) of erectile dysfunction. Sexual desire is associated with the fixed partner (OR: 0.12; 95% CI: 0.02–0.66), masturbation (OR: 0.13; 95% CI: 0.02–0.62), and sexual intercourse in the last month (OR: 0.13; 95% IC: 0.01–0.92). Ejaculation (OR: 0.01; 95% CI: 0.00–0.15) and erectile dysfunction (OR: 15.7; 95% CI: 1.38–178.58) are associated with orgasm. Psychogenic erection (OR: 0.07; 95% CI: 0.01–0.69), monthly frequency of sexual intercourse (OR: 11.3; 95% CI: 2.0–62.8), and orgasmic dysfunction (OR: 7.1; 95% CI: 1.1–44.8) are associated with satisfaction.
Conclusion. Fixed partner, ejaculation, masturbation are protective factors for sexual dysfunction. Erectile dysfunction, orgasmic, and infrequent sex dysfunction are predictors of sexual dysfunction.
Level of Evidence: 3

Compressive Pressure Versus Time in Cauda Equina Syndrome: A Systematic Review and Meta-Analysis of Experimental Studies

01-09-2019 – Pronin, Savva; Koh, Chan Hee; Bulovaite, Edita; Macleod, Malcolm R.; Statham, Patrick F.

Journal Article

Study Design. Systematic review and meta-analysis.
Objective. To examine the relationship between compressive pressure and its duration in cauda equina compression, and the effects of subsequent decompression, on neurophysiological function, and pathophysiology in animal studies. We further aim to investigate these relationships with systemic blood pressure to assess whether a vascular component in the underlying mechanism may contribute to the clinical heterogeneity of this disease.
Summary of Background Data. The complex relationship between preoperative factors and outcomes in cauda equina syndrome (CES) suggests heterogeneity within CES which may inform better understanding of pathophysiological process, their effect on neurological function, and prognosis.
Methods. Systematic review identified 17 relevant studies including 422 animals and reporting electrophysiological measures (EP), histopathology, and blood flow. Modeling using meta-regression analyzed the relationship between compressive pressure, duration of compression, and electrophysiological function in both compression and decompression studies.
Results. Modeling suggested that electrophysiological dysfunction in acute cauda equina compression has a sigmoidal response, with particularly deterioration when mean arterial blood pressure is exceeded and, additionally, sustained for approximately 1 hour. Accounting for pressure and duration may help risk-stratify patients pre-decompression. Outcomes after decompression appeared to be related more to the degree of compression, where exceeding systolic blood pressure tended to result in an irreversible lesion, rather than duration of compression. Prognosis was most strongly associated with residual pre-decompression function.
Conclusion. Compressive pressure influences effects and outcomes of cauda equina compression. We suggest the presence of two broad phenotypic groups within CES defined by the degree of ischaemia as a potential explanatory pathophysiological mechanism.
Level of Evidence: 1

Risk and Prognostic Factors of Low Back Pain: Repeated Population-based Cohort Study in Sweden

01-09-2019 – Halonen, Jaana I.; Shiri, Rahman; Magnusson Hanson, Linda L.; Lallukka, Tea

Journal Article

Study Design. Prospective longitudinal cohort study.
Objective. To determine the associations for workload and health-related factors with incident and recurrent low back pain (LBP), and to determine the mediating role of health-related factors in associations between physical workload factors and incident LBP.
Summary of Background Data. It is not known whether the risk factors for the development of LBP are also prognostic factors for recurrence of LBP and whether the associations between physical workload and incident LBP are mediated by health-related factors. We used data from the Swedish Longitudinal Occupational Survey of Health study. Those responding to any two subsequent surveys in 2010 to 2016 were included for the main analyses (N = 17,962). Information on occupational lifting, working in twisted positions, weight/height, smoking, physical activity, depressive symptoms, and sleep problems were self-reported. Incident LBP was defined as pain limiting daily activities in the preceding three months in participants free from LBP at baseline. Recurrent LBP was defined as having LBP both at baseline and follow-up. For the mediation analyses, those responding to three subsequent surveys were included (N = 3516).
Methods. Main associations were determined using generalized estimating equation models for repeated measures data. Mediation was examined with counterfactual mediation analysis.
Results. All risk factors at baseline but smoking and physical activity were associated with incident LBP after adjustment for confounders. The strongest associations were observed for working in twisted positions (risk ratio  = 1.52, 95% CI 1.37, 1.70) and occupational lifting (risk ratio  = 1.52, 95% CI 1.32, 1.74). These associations were not mediated by health-related factors. The studied factors did not have meaningful effects on recurrent LBP.
Conclusion. The findings suggest that workload and health-related factors have stronger effects on the development than on the recurrence or progression of LBP, and that health-related factors do not mediate associations between workload factors and incident LBP.
Level of Evidence: 3

Blood Loss of Posterior Lumbar Interbody Fusion on Lumbar Stenosis in Patients With Rheumatoid Arthritis: A Case–Control Study

01-09-2019 – Xu, Shuai; Liang, Yan; Wang, Jing; Yu, Guanjie; Guo, Chen; Zhu, Zhenqi; Liu, Haiying

Journal Article

Study Design. Case–control study.
Objective. To compare intraoperative bleeding, drainage, and hidden blood loss (HBL) of posterior lumbar interbody fusion (PLIF) on lumbar spinal stenosis (LSS) in patients with rheumatoid arthritis (RA) and non-RA and identify the risk factors of HBL with RA.
Summary of Background Data. Exploration on PLIF on LSS and HBL has been reported before while the comparison on total blood loss (TBL), especially HBL of PLIF or PLF on LSS between patients with RA and without RA has not been studied.
Methods. Sixty-one patients diagnosed LSS with RA (RA group) and 87 matched patients without RA (NRA group) were enrolled and demographic characteristics, RA-related parameters, operation and blood loss information were extracted. Intraoperative blood loss, drainage, and HBL were primary outcomes and secondary measures included operation time, hematocrit (Hct) and hemoglobin (Hb), the number of anemia and blood transfusion.
Results. There was no statistical difference in total blood loss (TBL), intraoperative blood loss, and postoperative drainage while HBL and the proportion of HBL in TBL were lower in NRA group (P 2 segments). The secondary outcomes showed the change of Hct was lower in NRA group (P = 0.021) but not the reduction of Hb. In addition, there was no significant difference in neoformative and grade-aggravated anemia, as well as the number of allogeneic blood transfusion and operation time showed Steinbroker classification, disease-modifying anti-rheumatic drugs (DMARDs), hange of Hb and allogeneic blood transfusion were risk factors for HBL with RA.
Conclusion. There was no difference in TBL, intraoperative bleeding, and operation time, but HBL were higher in RA patients particularly in long-segmental operation. Steinbroker classification, DMARDs, the change of Hb, and allogeneic blood transfusion were independent risk factors for HBL in RA patients.
Level of Evidence: 3