Patient-Reported Outcomes After Complex Adult Spinal Deformity Surgery: 5-Year Results of the Scoli-Risk-1 Study.

STUDY DESIGN: Prospective cohort. OBJECTIVE: To prospectively evaluate PROs up to 5-years after complex ASD surgery. METHODS: The Scoli-RISK-1 study enrolled 272 ASD patients undergoing surgery from 15 centers. Inclusion criteria was Cobb angle of >80°, corrective osteotomy for congenital or revision deformity, and/or 3-column osteotomy. The following PROs were measured prospectively at intervals up to 5-years postoperative: ODI, SF36-PCS/MCS, SRS-22, NRS back/leg. Among patients with 5-year follow-up, comparisons were made from both baseline and 2-years postoperative to 5-years postoperative. PROs were analyzed using mixed models for repeated measures. RESULTS: Seventy-seven patients (28.3%) had 5-year follow-up data. Comparing baseline to 5-year data among these 77 patients, significant improvement was seen in all PROs: ODI (45.2 vs. 29.3, P < 0.001), SF36-PCS (31.5 vs. 38.8, P < 0.001), SF36-MCS (44.9 vs. 49.1, P = 0.009), SRS-22-total (2.78 vs. 3.61, P < 0.001), NRS-back pain (5.70 vs. 2.95, P < 0.001) and NRS leg pain (3.64 vs. 2.62, P = 0.017). In the 2 to 5-year follow-up period, no significant changes were seen in any PROs. The percentage of patients achieving MCID from baseline to 5-years were: ODI (62.0%) and the SRS-22r domains of function (70.4%), pain (63.0%), mental health (37.5%), self-image (60.3%), and total (60.3%). Surprisingly, mean values (P > 0.05) and proportion achieving MCID did not differ significantly in patients with major surgery-related complications compared to those without. CONCLUSIONS: After complex ASD surgery, significant improvement in PROs were seen at 5-years postoperative in ODI, SF36-PCS/MCS, SRS-22r, and NRS-back/leg pain. No significant changes in PROs occurred during the 2 to 5-year postoperative period. Those with major surgery-related complications had similar PROs and proportion of patients achieving MCID as those without these complications.

The Scoli-RISK 1 results of lower extremity motor function 5 years after complex adult spinal deformity surgery.

INTRODUCTION: Neurologic complications after complex adult spinal deformity (ASD) surgery are important, yet outcomes are heterogeneously reported, and long-term follow-up of actual lower extremity motor function is unknown. OBJECTIVE: To prospectively evaluate lower extremity motor function scores (LEMS) before and at 5 years after surgical correction of complex ASD. DESIGN: Retrospective analysis of a prospective, multicenter, international observational study. METHODS: The Scoli-RISK-1 study enrolled 272 ASD patients undergoing surgery from 15 centers around the world. Inclusion criteria were Cobb angle of > 80°, corrective osteotomy for congenital or revision deformity and/or 3-column osteotomy. Among patients with 5-year follow-up, comparisons of LEMS to baseline and within each follow-up period were made via documented neurologic exams on each patient. RESULTS: Seventy-seven (28.3%) patients had 5-year follow-up. Among these 77 patients with 5-year follow-up, rates of postoperative LEMS deterioration were: 14.3% hospital discharge, 10.7% at 6 weeks, 6.5% at 6 months, 9.5% at 2 years and 9.3% at 5 years postoperative. During the 2-5 year window, while mean LEMS did not change significantly (-0.5, p = 0.442), eight (11.1%) patients deteriorated (of which 3 were ≥ 4 motor points), and six (8.3%) patients improved (of which 2 were ≥ 4 points). Of the 14 neurologic complications, four (28.6%) were surgery-related, three of which required reoperation. While mean LEMS were not impacted in patients with a major surgery-related complication, mean LEMS were significantly lower in patients with neurologic surgery-related complications at discharge (p = 0.041) and 6 months (p = 0.008) between the two groups as well as the change from baseline to 5 years (p = 0.041). CONCLUSIONS: In 77 patients undergoing complex ASD surgery with 5-year follow-up, while mean LEMS did not change from 2 to 5 years, subtle neurologic changes occurred in approximately 1 in 5 patients (11.1% deteriorated; 8.3% improved). Major surgery-related complication did not result in decreased LEMS; however, those with neurologic surgery-related complications continued to have decreased lower extremity motor function at 5 years postoperative. These results underscore the importance of long-term follow-up to 5 years, using individual motor scores rather than group averages, and comparing outcomes to both baseline and last follow-up.

Impact of New Motor Deficit on HRQOL After Adult Spinal Deformity Surgery: Subanalysis From Scoli Risk 1 Prospective Study.

STUDY DESIGN: International, multicenter, prospective, longitudinal observational cohort. OBJECTIVE: To assess how new motor deficits affect patient reported quality of life scores after adult deformity surgery. SUMMARY OF BACKGROUND DATA: Adult spinal deformity surgery is associated with high morbidity, including risk of new postoperative motor deficit. It is unclear what effect new motor deficit has on Health-related Quality of Life scores (HRQOL) scores. METHODS: Adult spinal deformity patients were enrolled prospectively at 15 sites worldwide. Other inclusion criteria included major Cobb more than 80°, C7-L2 curve apex, and any patient undergoing three column osteotomy. American Spinal Injury Association (ASIA) scores and standard HRQOL scores were recorded pre-op, 6 weeks, 6 months, and 2 years. RESULTS: Two hundred seventy two complex adult spinal deformity (ASD) patients enrolled. HRQOL scores were worse for patients with lower extremity motor score (LEMS). Mean HRQOL changes at 6 weeks and 2 years compared with pre-op for patients with motor worsening were: ODI (+12.4 at 6 weeks and -4.7 at 2 years), SF-36v2 physical (-4.5 at 6 weeks and +2.3 at 2 years), SRS-22r (0.0 at 6 weeks and +0.4 at 2 years). Mean HRQOL changes for motor-neutral patients were: ODI (+0.6 at 6 weeks and -12.1 at 2 years), SF-36v2 physical (-1.6 at 6 weeks and +5.9 at 2 years), and SRS-22r (+0.4 at 6 weeks and +0.7 at 2 years). For patients with LEMS improvement, mean HRQOL changes were: ODI (-0.6 at 6 weeks and -16.3 at 2 years), SF-36v2 physical (+1.0 at 6 weeks and +7.0 at 2 years), and SRS-22r (+0.5 at 6 weeks and +0.9 at 2 years). CONCLUSION: In the subgroup of deformity patients who developed a new motor deficit, total HRQOLs and HRQOL changes were negatively impacted. Patients with more than 2 points of LEMS worsening had the worst changes, but still showed overall HRQOL improvement at 6 months and 2 years compared with pre-op baseline.Level of Evidence: 3.

Are Higher Global Alignment and Proportion Scores Associated With Increased Risks of Mechanical Complications After Adult Spinal Deformity Surgery? An External Validation.

BACKGROUND: The Global Alignment and Proportion (GAP) score, based on pelvic incidence-based proportional parameters, was recently developed to predict mechanical complications after surgery for spinal deformities in adults. However, this score has not been validated in an independent external dataset. QUESTIONS/PURPOSES: After adult spinal deformity surgery, is a higher GAP score associated with (1) an increased risk of mechanical complications, defined as rod fractures, implant-related complications, proximal or distal junctional kyphosis or failure; (2) a higher likelihood of undergoing revision surgery to treat a mechanical complication; and (3) is a lower (more proportioned) GAP score category associated with better validated outcomes scores using the Oswestry Disability Index (ODI), Scoliosis Research Society-22 (SRS-22) and the Short Form-36 questionnaires? METHODS: A total of 272 patients who had undergone corrective surgeries for complex spinal deformities were enrolled in the Scoli-RISK-1 prospective trial. Patients were included in this secondary analysis if they fulfilled the original inclusion criteria by Yilgor et al. From the original 272 patients, 14% (39) did not satisfy the radiographic inclusion criteria, the GAP score could not be calculated in 14% (37), and 24% (64) did not have radiographic assessment at postoperative 2 years, leaving 59% (159) for analysis in this review of data from the original trial. A total of 159 patients were included in this study,with a mean age of 58 ± 14 years at the time of surgery. Most patients were female (72%, 115 of 159), the mean number of levels involved in surgery was 12 ± 4, and three-column osteotomy was performed in 76% (120 of 159) of patients. The GAP score was calculated using parameters from early postoperative radiographs (between 3 and 12 weeks) including pelvic incidence, sacral slope, lumbar lordosis, lower arc lordosis and global tilt, which were independently obtained from a computer software based on centralized patient radiographs. The GAP score was categorized as proportional (scores of 0 to 2), moderately disproportional (scores of 3 to 6), or severely disproportional (scores higher than 7 to 13). Receiver operating characteristic area under curve (AUC) was used to assess associations between GAP score and risk of mechanical complications and risk of revision surgery. An AUC of 0.5 to 0.7 was classified as "no or low associative power", 0.7 to 0.9 as "moderate" and greater than 0.9 as "high". We analyzed differences in validated outcome scores between the GAP categories using Wilcoxon rank sum test. RESULTS: At a minimum of 2 years' follow-up, a higher GAP score was not associated with increased risks of mechanical complications (AUC = 0.60 [95% CI 0.50 to 0.70]). A higher GAP score was not associated with a higher likelihood of undergoing a revision surgery to treat a mechanical complication (AUC = 0.66 [95% 0.53 to 0.78]). However, a moderately disproportioned GAP score category was associated with better SF-36 physical component summary score (36 ± 10 versus 40 ± 11; p = 0.047), better SF-36 mental component summary score (46 ± 13 versus 51 ± 12; p = 0.01), better SRS-22 total score (3.4 ± 0.8 versus 3.7 ± 0.7, p = 0.02) and better ODI score (35 ± 21 versus 25 ± 20; p = 0.003) than severely disproportioned GAP score category. CONCLUSION: Based on the findings of this external validation study, we found that alignment targets based on the GAP score alone were not associated with increased risks of mechanical complications and mechanical revisions in patients with complex adult spinal disorders. Parameters not included in the original GAP score needed to be considered to reduce the likelihood of mechanical complications. LEVEL OF EVIDENCE: Level III, diagnostic study.

The Effect of Tobacco Smoking on Adverse Events Following Adult Complex Deformity Surgery: Analysis of 270 Patients From the Prospective, Multicenter Scoli-RISK-1 Study.

STUDY DESIGN: Post-hoc analysis of a prospective, multicenter cohort study. OBJECTIVE: To analyze the impact of smoking on rates of postoperative adverse events (AEs) in patients undergoing high-risk adult spine deformity surgery. SUMMARY OF BACKGROUND DATA: Smoking is a known predictor of medical complications after adult deformity surgery, but the effect on complications, implant failure and other AEs has not been adequately described in prospective studies. METHODS: Twenty-six patients with a history of current smoking were identified out of the 272 patients enrolled in the SCOLI-RISK-1 study who underwent complex adult spinal deformity surgery at 15 centers, with 2-year follow-up. The outcomes and incidence of AEs in these patients were compared to the nonsmoking cohort (n = 244) using univariate analysis, with additional multivariate regression to adjust for the effect of patient demographics, complexity of surgery, and other confounders. RESULTS: The number of levels and complexity of surgery in both cohorts were comparable. In the univariate analysis, the rates of implant failure were almost double (odds ratio 2.28 [0.75-6.18]) in smoking group (n = 7; 26.9%)) that observed in the nonsmoking group (n = 34; 13.9%), but this was not statistically significant (P = 0.088). Surgery-related excessive bleeding (>4 L) was significantly higher in the smoking group (n = 5 vs. n = 9; 19.2% vs. 3.7%; OR 6.22[1.48 - 22.75]; P = 0.006). Wound infection rates and respiratory complications were similar in both groups. In the multivariate analysis, the smoking group demonstrated a higher incidence of any surgery-related AEs over 2 years (n = 13 vs. n = 95; 50.0% vs. 38.9%; OR 2.12 [0.88-5.09]) (P = 0.094). CONCLUSION: In this secondary analysis of patients from the SCOLI-RISK-1 study, a history of smoking significantly increased the risk of excessive intraoperative bleeding and nonsignificantly increased the rate of implant failure or surgery-related AEs over 2 years. The authors therefore advocate a smoking cessation program in patients undergoing complex adult spine deformity surgery. LEVEL OF EVIDENCE: 2.

Non-neurologic adverse events after complex adult spinal deformity surgery: results from the prospective, multicenter Scoli-RISK-1 study.

PURPOSE: Accurate information regarding the expected complications of complex adult spinal deformity (ASD) is important for shared decision making and informed consent. The purpose of the present study was to investigate the rate and types of non-neurologic adverse events after complex ASD surgeries, and to identify risk factors that affect their occurrence. METHODS: The details and occurrence of all non-neurologic adverse events were reviewed in a prospective cohort of 272 patients after complex ASD surgical correction in a mulitcentre database of the Scoli-RISK-1 study with a planned follow-up of 2 years. Logistic regression analyses were used to identify potential risk factors for non-neurologic adverse events. RESULTS: Of the 272 patients, 184 experienced a total of 515 non-neurologic adverse events for an incidence of 67.6%. 121 (44.5%) patients suffered from more than one adverse event. The most frequent non-neurologic adverse events were surgically related (27.6%), of which implant failure and dural tear were most common. In the unadjusted analyses, significant factors for non-neurologic adverse events were age, previous spine surgery performed, number of documented non-neurologic comorbidities and ASA grade. On multivariable logistic regression analysis, previous spine surgery was the only independent risk factor for non-neurologic adverse events. CONCLUSIONS: The incidence of non-neurologic adverse events for patients undergoing corrective surgeries for ASD was 67.6%. Previous spinal surgery was the only independent risk factor predicting the occurrence of non-neurologic adverse events. These findings complement the earlier report of neurologic complications after ASD surgeries from the Scoli-RISK-1 study. These slides can be retrieved under Electronic Supplementary Material.

Unilateral versus bilateral lower extremity motor deficit following complex adult spinal deformity surgery: is there a difference in recovery up to 2-year follow-up?

BACKGROUND CONTEXT: Scoli-RISK-1 is a multicenter prospective cohort designed to study neurologic outcomes following complex adult spinal deformity (ASD). The effect of unilateral versus bilateral postoperative motor deficits on the likelihood of long-term recovery has not been previously studied in this population. PURPOSE: To evaluate whether bilateral postoperative neurologic deficits have a worse recovery than unilateral deficits. STUDY DESIGN: Secondary analysis of a prospective, multicenter, international cohort study. METHODS: In a cohort of 272 patients, neurologic decline was defined as deterioration of the American Spinal Injury Association Lower Extremity Motor Scores (LEMS) following surgery. Patients with lower extremity neurologic decline were grouped into unilateral and bilateral cohorts. Differences in demographics, surgical variables, and patient outcome measures between the two cohorts were analyzed. RESULTS: A total of 265 patients had LEMS completed at discharge. Unilateral decline was seen in 32 patients (12%), while 29 (11%) had bilateral symptoms. At 2 years, there was no significant difference in either median LEMS (unilateral 50.0, interquartile range [IQR] 47.5-50.0; bilateral 50.0, IQR 48.0-50.0, p=.939) or change in LEMS from baseline (unilateral 0.0, IQR -1.0 to 0.0; bilateral 0.0, IQR -1.0 to 0.0, p=.920). In both groups, approximately two-thirds of patients saw recovery to at least their preoperative baseline by 2 years postoperatively (unilateral n=15, 63%; bilateral n=14, 67%). The mean Scoliosis Research Society-22R (SRS-22R) score at 2 years was 3.7±0.6 versus 3.2±0.6 (p=.009) for unilateral and bilateral groups, respectively. CONCLUSIONS: The prognosis for neurologic recovery of new motor deficits following complex adult spinal deformity is similar with both unilateral and bilateral weaknesses. Despite similar rates of neurologic recovery, patient reported outcomes for those with bilateral motor decline measured by SRS-22R are worse at 2 years after surgery.

Predictive factors of survival in a surgical series of metastatic epidural spinal cord compression and complete external validation of 8 multivariate models of survival in a prospective North American multicenter study.

BACKGROUND: This study was designed to identify preoperative predictors of survival in surgically treated patients with metastatic epidural spinal cord compression (MESCC), to examine how these predictors are related to 8 prognostic models, and to perform the first full external validation of these models in accordance with the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) statement. METHODS: One hundred forty-two surgically treated patients with MESCC were enrolled in a prospective, multicenter North American cohort study and were followed for 12 months or until death. Cox regression was used. Noncollinear predictors with < 10% missing data, with ≥ 10 events per stratum, and with P < .05 in a univariate analysis were tested through a backward stepwise selection. For the original and revised Tokuhashi prognostic scoring systems (PSSs), Tomita PSS, modified Bauer PSS, van der Linden PSS, Bartels model, Oswestry Spinal Risk Index, and Bollen PSS, this study examined calibration graphically, discrimination with Harrell c-statistics, and survival stratified by risk groups with the Kaplan-Meier method and log-rank test. RESULTS: The following were significant in the univariate analysis: type of primary tumor, sex, organ metastasis, body mass index, preoperative radiotherapy to MESCC, physical component (PC) of the 36-Item Short Form Health Survey, version 2 (SF-36v2), and EuroQol 5-Dimension (EQ-5D) Questionnaire. Breast, prostate and thyroid primary tumor (HR: 2.9; P =.0005), presence of organ metastasis (hazard ratio (HR): 2.0; P = .005) and SF-36v2 PC (HR: 0.95; P < .0001) were associated with survival in multivariable analysis. Predicted prognoses poorly matched observed values on calibration plots; Bartels model calibration slope was 0.45. Bollen PSS (0.61; 95% CI: 0.58-0.64) and Bartels model (0.68; 95% CI: 0.65-0.71) had the lowest and highest c-statistics, respectively. CONCLUSIONS: The primary tumor type (breast, prostate, or thyroid), an absence of organ metastasis, and a lower degree of physical disability are preoperative predictors of longer survival for surgical MESCC patients. These results are in keeping with current models. This full external validation of 8 prognostic PSSs or model of survival in surgical MESCC patients has revealed that calibration is poor, especially for long-term survivors, whereas discrimination is possibly helpful.

An Analysis of the Incidence and Outcomes of Major Versus Minor Neurological Decline After Complex Adult Spinal Deformity Surgery: A Subanalysis of Scoli-RISK-1 Study.

STUDY DESIGN: A subanalysis from a prospective, multicenter, international cohort study in 15 sites (Scoli-RISK-1). OBJECTIVE: To report detailed information regarding the severity of neurological decline related to complex adult spine deformity (ASD) surgery and to examine outcomes based on severity. SUMMARY OF BACKGROUND DATA: Postoperative neurological decline after ASD surgeries can occur due to nerve root(s) or spinal cord dysfunction. The impact of decline and the pattern of recovery may be related to the anatomic location and the severity of the injury. METHODS: An investigation of 272 prospectively enrolled complex ASD surgical patients with neurological status measured by American Spinal Injury Association Lower Extremity Motor Scores (LEMS) was undertaken. Postoperative neurological decline was categorized into "major" (≥5 points loss) versus "minor" (<5 points loss) deficits. Timing and extent of recovery in LEMS were investigated for each group. RESULTS: Among the 265 patients with LEMS available at discharge, 61 patients (23%) had neurological decline, with 20 (33%) experiencing major decline. Of note, 90% of the patients with major decline had deficits in three or more myotomes. Full recovery was seen in 24% at 6 weeks and increased to 65% at 6 months. However, 34% continued to experience some neurological decline at 24 months, with 6% demonstrating no improvement. Of 41 patients (67%) with minor decline, 73% had deficits in one or two myotomes. Full recovery was seen in 49% at 6 weeks and increased to 70% at 6 months. Of note, 26% had persistence of some neurological deficit at 24 months, with 18% demonstrating no recovery. CONCLUSION: In patients undergoing complex ASD correction, a rate of postoperative neurological decline of 23% was noted with 33% of these being "major." Although most patients showed substantial recovery by 6 months, approximately one-third continued to experience neurological dysfunction. LEVEL OF EVIDENCE: 2.

External Validation of the Adult Spinal Deformity (ASD) Frailty Index (ASD-FI) in the Scoli-RISK-1 Patient Database.

STUDY DESIGN: Analysis of a prospective multicenter database. OBJECTIVE: To assess the ability of the recently created Adult Spinal Deformity (ASD) Frailty Index (ASD-FI) to predict odds of major complications and length of hospital stay for patients who had more severe preoperative deformity and underwent more invasive ASD surgery compared with patients in the database used to create the index. SUMMARY OF BACKGROUND DATA: Accurate preoperative estimates of risk are necessary given the high complication rates currently associated with ASD surgery. METHODS: Patients were enrolled by participating institutions in Europe, Asia, and North America from 2009 to 2011. ASD-FI scores were used to classify 267 patients as not frail (NF) (<0.3), frail (0.3-0. 5), or severely frail (SF) (>0.5). Multivariable logistic regression, adjusted for preoperative and surgical covariates such as operative time and blood loss, was performed to determine the relationship between ASD-FI category and incidence of major complications, overall incidence of complications, and length of hospital stay. RESULTS: The mean ASD-FI score was 0.3 (range, 0-0.7). We categorized 105 patients as NF, 103 as frail, and 59 as SF. The adjusted odds of developing a major complication were higher for SF patients (odds ratio = 4.4; 95% CI 2.0, 9.9) compared with NF patients. After adjusting for covariates, length of hospital stay for SF patients increased by 19% (95% CI 1.4%, 39%) compared with NF patients. The odds of developing a major complication or having increased length of stay were similar between frail and NF patients. CONCLUSION: Greater patient frailty, as measured by the ASD-FI, is associated with a longer hospital stay and greater risk of major complications among patients who have severe preoperative deformity and undergo invasive surgical procedures. LEVEL OF EVIDENCE: 2.

Lower Extremity Motor Function Following Complex Adult Spinal Deformity Surgery: Two-Year Follow-up in the Scoli-RISK-1 Prospective, Multicenter, International Study.

BACKGROUND: The reported neurologic complication rate following surgery for complex adult spinal deformity (ASD) is variable due to several factors. Most series have been retrospective with heterogeneous patient populations and use of nonuniform neurologic assessments. The aim of this study was to prospectively document lower extremity motor function by means of the American Spinal Injury Association (ASIA) lower extremity motor score (LEMS) before and through 2 years after surgical correction of complex ASD. METHODS: The Scoli-RISK-1 study enrolled 272 patients with ASD, from 15 centers, who had undergone primary or revision surgery for a major Cobb angle of ≥80°, corrective osteotomy for congenital spinal deformity or as a revision procedure for any type of deformity, and/or a complex 3-column osteotomy. RESULTS: One of 272 patients lacked preoperative data and was excluded from the analysis, and 62 (22.9%) of the remaining 271 patients, who were included, lacked a 2-year postoperative assessment. Patients with no preoperative motor impairment (normal LEMS group; n = 203) had a small but significant decline from the mean preoperative LEMS value (50) to that at 2 years postoperatively (49.66 [95% confidence interval = 49.46 to 49.85]; p = 0.002). Patients who did have a motor deficit preoperatively (n = 68; mean LEMS, 43.79) had significant LEMS improvement at 6 months (47.21, p < 0.001) and 2 years (46.12, p = 0.003) postoperatively. The overall percentage of patients (in both groups combined) who had a postoperative LEMS decline, compared with the preoperative value, was 23.0% at discharge, 17.1% at 6 weeks, 9.9% at 6 months, and 10.0% at 2 years. CONCLUSIONS: The percentage of patients who had a LEMS decline (compared with the preoperative score) after undergoing complex spinal reconstructive surgery for ASD was 23.0% at discharge, which improved to 10.0% at 2 years postoperatively. These rates are higher than previously reported, which we concluded was due to the prospective, strict nature of the LEMS testing of patients with these challenging deformities. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Incidence and risk factors of postoperative neurologic decline after complex adult spinal deformity surgery: results of the Scoli-RISK-1 study.

BACKGROUND CONTEXT: Significant variability in neurologic outcomes after surgical correction for adult spinal deformity (ASD) has been reported. Risk factors for decline in neurologic motor outcomes are poorly understood. PURPOSE: The objective of the present investigation was to identify the risk factors for postoperative neurologic motor decline in patients undergoing complex ASD surgery. STUDY DESIGN/SETTING: This is a prospective international multicenter cohort study. PATIENT SAMPLE: From September 2011 to October 2012, 272 patients undergoing complex ASD surgery were prospectively enrolled in a multicenter, international cohort study in 15 sites. OUTCOME MEASURES: Neurologic decline was defined as any postoperative deterioration in American Spinal Injury Association lower extremity motor score (LEMS) compared with preoperative status. METHODS: To identify risk factors, 10 candidate variables were selected for univariable analysis from the dataset based on clinical relevance, and a multivariable logistic regression analysis was used with backward stepwise selection. RESULTS: Complete datasets on 265 patients were available for analysis and 61 (23%) patients showed a decline in LEMS at discharge. Univariable analysis showed that the key factors associated with postoperative neurologic deterioration included older age, lumbar-level osteotomy, three-column osteotomy, and larger blood loss. Multivariable analysis revealed that older age (odds ratio [OR]=1.5 per 10 years, 95% confidence interval [CI] 1.1-2.1, p=.005), larger coronal deformity angular ratio [DAR] (OR=1.1 per 1 unit, 95% CI 1.0-1.2, p=.037), and lumbar osteotomy (OR=3.3, 95% CI 1.2-9.2, p=.022) were the three major predictors of neurologic decline. CONCLUSIONS: Twenty-three percent of patients undergoing complex ASD surgery experienced a postoperative neurologic decline. Age, coronal DAR, and lumbar osteotomy were identified as the key contributing factors.

Ewing Sarcoma of the Spine: Prognostic Variables for Survival and Local Control in Surgically Treated Patients.

STUDY DESIGN: Multicenter, ambispective observational study. OBJECTIVE: To quantify mortality and local recurrence after surgical treatment of spinal Ewing sarcoma (ES) and to determine whether an Enneking appropriate procedure and surgical margins (en bloc resection with wide/marginal margins) are associated with improved prognosis. SUMMARY OF BACKGROUND DATA: Treatment of primary ES of the spine is complex. Ambiguity remains regarding the role and optimal type of surgery in the treatment of spinal ES. METHODS: The AOSpine Knowledge Forum Tumor developed a multicenter database including demographics, diagnosis, treatment, mortality, and recurrence rate data for spinal ES. Patients were stratified based on surgical margins and Enneking appropriateness. Survival and recurrence were analyzed using Kaplan-Meier curves and log-rank tests. RESULTS: Fifty-eight patients diagnosed with primary spinal ES underwent surgery. Enneking appropriateness of surgery was known for 55 patients; 24 (44%) treated Enneking appropriately (EA) and 31 (56%) treated Enneking inappropriately (EI). A statistically significant difference in favor of EA-treated patients was found with regards to survival (P = 0.034). Neoadjuvant and postoperative chemotherapy was significantly associated with increased survival (P = 0.008). Local recurrence occurred in 22% (N = 5) of patients with an EA procedure versus 38% (N = 11) of patients with an EI procedure. The timing of chemotherapy treatment was significantly different between the Enneking cohorts (P < 0.001) and all EA-treated patients received chemotherapy treatment. Although, local recurrence was not significantly different between Enneking cohorts (P = 0.140), intralesional surgical margins and patients who received a previous spine tumor operation were associated with increased local recurrence (P = 0.025 and P = 0.018, respectively). CONCLUSION: Surgery should be undertaken when an en bloc resection with wide/marginal margins is feasible. An EA surgery correlates with improved survival, but the impact of other prognostic factors needs to be evaluated. En bloc resection with wide/marginal margins is associated with local control. LEVEL OF EVIDENCE: 3.

Geographic variations in clinical presentation and outcomes of decompressive surgery in patients with symptomatic degenerative cervical myelopathy: analysis of a prospective, international multicenter cohort study of 757 patients.

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness. PURPOSE: The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions. STUDY DESIGN/SETTING: This is a multicenter international prospective cohort study. PATIENT SAMPLE: This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine. OUTCOME MEASURES: The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade. MATERIALS AND METHODS: The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America. RESULTS: Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p<.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe. CONCLUSIONS: Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM.

Treatment of Axis Body Fractures: A Systematic Review.

STUDY DESIGN: Evidence-based systematic review. OBJECTIVES: To define the optimal treatment of fractures involving the C2 body, including those with concomitant injuries, based upon a systematic review of the literature. SUMMARY OF BACKGROUND DATA: Axis body fractures have customarily been treated nonoperatively, but there are some injuries that may require operative intervention. High-quality literature is sparse and there are few class I or class II studies to guide treatment decisions. MATERIALS AND METHODS: A literature search was conducted using PubMed (MEDLINE), Cochrane Central Register of Controlled Trials, and Scopus (EMBASE, MEDLINE, COMPENDEX). The quality of literature was rated according to a grading tool developed by the Center for Evidence-based Medicine. Operative and nonoperative treatment of axis body fractures were compared using fracture bony union as the primary outcome measure. As risk factors for nonunion were not consistently reported, cases were analyzed individually. RESULTS: The literature search identified 62 studies, of which 10 were case reports which were excluded from the analysis. A total of 920 patients from 52 studies were included. The overall bony union rate for all axis body fractures was 91%. Although the majority of fractures were treated nonoperatively, there has been an increasing trend toward operative intervention for Benzel type III (transverse) axis body fractures. Nearly 76% of axis body fractures were classified as type III fractures, of which 88% united successfully. Nearly all Benzel type I and type II axis body fractures were successfully treated nonoperatively. The risk factors for nonunion included: a higher degree of subluxation, fracture displacement, comminution, concurrent injuries, delay in treatment, and older age. CONCLUSIONS: High rates for fracture union are reported in the literature for axis body fractures with nonoperative treatment. High-quality prospective studies are required to develop consensus as to which C2 body fractures require operative fixation.

Surgical management of spinal osteoblastomas.

OBJECTIVE Osteoblastoma is a rare primary benign bone tumor with a predilection for the spinal column. Although of benign origin, osteoblastomas tend to behave more aggressively clinically than other benign tumors. Because of the low incidence of osteoblastomas, evidence-based treatment guidelines and high-quality research are lacking, which has resulted in inconsistent treatment. The goal of this study was to determine whether application of the Enneking classification in the management of spinal osteoblastomas influences local recurrence and survival time. METHODS A multicenter database of patients who underwent surgical intervention for spinal osteoblastoma was developed by the AOSpine Knowledge Forum Tumor. Patient data pertaining to demographics, diagnosis, treatment, cross-sectional survival, and local recurrence were collected. Patients in 2 cohorts, based on the Enneking classification of the tumor (Enneking appropriate [EA] and Enneking inappropriate [EI]), were analyzed. If the final pathology margin matched the Enneking-recommended surgical margin, the tumor was classified as EA; if not, it was classified as EI. RESULTS A total of 102 patients diagnosed with a spinal osteoblastoma were identified between November 1991 and June 2012. Twenty-nine patients were omitted from the analysis because of short follow-up time, incomplete survival data, or invalid staging, which left 73 patients for the final analysis. Thirteen (18%) patients suffered a local recurrence, and 6 (8%) patients died during the study period. Local recurrence was strongly associated with mortality (relative risk 9.2; p = 0.008). When adjusted for Enneking appropriateness, this result was not altered significantly. No significant differences were found between the EA and EI groups in regard to local recurrence and mortality. CONCLUSIONS In this evaluation of the largest multicenter cohort of spinal osteoblastomas, local recurrence was found to be strongly associated with mortality. Application of the Enneking classification as a treatment guide for preventing local recurrence was not validated.

En Bloc Resection Versus Intralesional Surgery in the Treatment of Giant Cell Tumor of the Spine.

STUDY DESIGN: Multicenter, ambispective observational study. OBJECTIVE: The aim of this study was to quantify local recurrence (LR) and mortality rates after surgical treatment of spinal giant cell tumor and to determine whether en bloc resection with wide/marginal margins is associated with improved prognosis compared to an intralesional procedure. SUMMARY OF BACKGROUND DATA: Giant cell tumor (GCT) of the spine is a rare primary bone tumor known for its local aggressiveness. Optimal surgical treatment remains to be determined. METHODS: The AOSpine Knowledge Forum Tumor developed a comprehensive multicenter database including demographics, presentation, diagnosis, treatment, mortality, and recurrence rate data for GCT of the spine. Patients were analyzed based on surgical margins, including Enneking appropriateness. RESULTS: Between 1991 and 2011, 82 patients underwent surgery for spinal GCT. According to the Enneking classification, 59 (74%) tumors were classified as S3-aggressive and 21 (26%) as S2-active. The surgical margins were wide/marginal in 27 (36%) patients and intralesional in 48 (64%) patients. Thirty-nine of 77 (51%) underwent Enneking appropriate (EA) treatment and 38 (49%) underwent Enneking inappropriate (EI) treatment. Eighteen (22%) patients experienced LR. LR occurred in 11 (29%) EI-treated patients and six (15%) EA-treated patients (P = 0.151). There was a significant difference between wide/marginal margins and intralesional margins for LR (P = 0.029). Seven (9%) patients died. LR is strongly associated with death (Relative Risk 8.9, P < 0.001). Six (16%) EI-treated patients and one (3%) EA-treated patients died (P = 0.056). With regards to surgical margins, all patients who died underwent intralesional resection (P = 0.096). CONCLUSION: En bloc resection with wide/marginal margins should be performed when technically feasible because it is associated with decreased LR. Intralesional resection is associated with increased LR, and mortality correlates with LR. LEVEL OF EVIDENCE: 3.

A multicenter cohort study of spinal osteoid osteomas: results of surgical treatment and analysis of local recurrence.

BACKGROUND CONTEXT: Spinal osteoid osteomas are benign primary tumors arising predominantly from the posterior column of the spine. These "osteoblastic" lesions have traditionally been treated with intralesional excision. PURPOSE: The purpose of the present study was to review the treatment and local recurrence rates for symptomatic spinal osteoid osteomas. STUDY DESIGN/SETTING: Multicenter ambispective cross-sectional observational cohort study. PATIENT SAMPLE: During the study period, a total of 84 patients (65 males, 19 females) were diagnosed with a spinal osteoid osteoma and received surgical treatment. The mean age at surgery was 21.8 ± 9.0 years (range: 6.7-52.4 years) and the mean follow-up was 2.7 years (13 days-14.5 years). OUTCOME MEASURES: Local recurrence, perioperative morbidity, and cross-sectional survival. METHODS: Using the AOSpine Knowledge Forum Tumor multicenter ambispective database, surgically treated osteoid osteoma cases were identified. Patient demographic, clinical and diagnostic, treatment, local recurrence, perioperative morbidity, and cross-sectional survival data were collected and retrieved. Descriptive statistics were summarized using mean/standard deviation or frequency/percentage. RESULTS: In our study, most of the tumors were localized in the mobile spine (81 of 84 [96%]); all patients reported pain as a symptom. According to the postoperative assessment, 10 (12%) patients received an en bloc resection with marginal or wide margins, whereas two (2%) patients received en bloc resections with intralesional margins, 69 (82%) patients were treated by piecemeal "intralesional" resection, and three (4%) patients were not assessed. A total of six patients (7%) experienced a local recurrence, all of which occurred in patients who had received an intralesional resection. CONCLUSIONS: Benign bone-forming tumors of the spine are uncommon. Most patients in our series underwent a piecemeal resection with intralesional margins. This remains safe with a low local recurrence rate. En bloc excision may provide more chance of complete excision of the nidus but is not mandatory. The importance of complete excision of the nidus cannot be overemphasized.

Malignant peripheral nerve sheath tumors of the spine: results of surgical management from a multicenter study.

OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft-tissue sarcomas. Resection is the mainstay of treatment and the most important prognostic factor. However, complete resection of spinal MPNSTs with tumor-free margins is challenging due to the likelihood of residual tumor cells. The objective of this study was to describe whether the type of Enneking resection in the management of spinal MPNSTs had an effect on local recurrence and survival. METHODS The AOSpine Knowledge Forum Tumor developed a multicenter database that includes demographic, diagnostic, therapeutic, local recurrence, and survival data on patients with primary spinal column tumors. Patients who had undergone surgery for a primary spinal MPNST were included and were analyzed in 2 groups: 1) those undergoing Enneking appropriate (EA) resections and 2) those undergoing Enneking inappropriate (EI) resections. EA surgery was performed if there was histopathological evidence of an intact tumor pseudocapsule and at least a marginal resection on a vital structure. EI surgery was performed if there was an intentional or inadvertent transgression of the margin. RESULTS Between 1993 and 2012, 29 primary spine MPNSTs were identified in 12 (41%) females and 17 (59%) males with a mean age at diagnosis of 40 ± 17 years (range 5-74 years). The median patient follow-up was 1.3 years (range 42 days to 11.2 years). In total, 14 (48%) patients died and 14 (48%) patients suffered a local recurrence, 10 (71%) of whom died. Within 2 years after surgery, the median survival and local recurrence were not achieved. Data about Enneking appropriateness of surgery were available for 27 patients; 9 (33%) underwent an EA procedure and 18 (67%) underwent an EI procedure. Enneking appropriateness did not have a significant influence on local recurrence or survival. Twenty-two patients underwent adjuvant treatment with combined chemo- and radiotherapy (n = 7), chemotherapy alone (n = 3), or radiotherapy alone (n = 12). Adjuvant therapy had no significant influence on recurrence or survival. CONCLUSIONS The rates of recurrence and survival were similar for spinal MPNSTs regardless of whether patients had an EA or EI resection or received adjuvant therapy. Other factors such as variability of pathologist interpretation, PET CT correlation, or neurofibromatosis Type 1 status may play a role in patient outcome. Nonetheless, MPNSTs should still be treated as sarcomas until further evidence is known. The authors recommend an individualized approach with careful multidisciplinary decision making, and the patient should be informed about the morbidity of en bloc surgery when considering MPNST resection.

Spinal column chordoma: prognostic significance of clinical variables and T (brachyury) gene SNP rs2305089 for local recurrence and overall survival.

Background: Chordomas are rare, locally aggressive bony tumors associated with poor outcomes. Recently, the single nucleotide polymorphism (SNP) rs2305089 in the T (brachyury) gene was strongly associated with sporadic chordoma development, but its clinical utility is undetermined. Methods: In 333 patients with spinal chordomas, we identified prognostic factors for local recurrence-free survival (LRFS) and overall survival and assessed the prognostic significance of the rs2305089 SNP. Results: The median LRFS was 5.2 years from the time of surgery (95% CI: 3.8-6.0); greater tumor volume (≥100cm3) (hazard ratio [HR] = 1.99, 95% CI: 1.26-3.15, P = .003) and Enneking inappropriate resections (HR = 2.35, 95% CI: 1.37-4.03, P = .002) were independent predictors of LRFS. The median overall survival was 7.0 years (95% CI: 5.8-8.4), and was associated with older age at surgery (HR = 1.11 per 5-year increase, 95% CI: 1.02-1.21, P = .012) and previous surgical resection (HR = 1.73, 95% CI: 1.03-2.89, P = .038). One hundred two of 109 patients (93.6%) with available pathologic specimens harbored the A variant at rs2305089; these patients had significantly improved survival compared with those lacking the variant (P = .001), but there was no association between SNP status and LRFS (P = .876). Conclusions: The ability to achieve a wide en bloc resection at the time of the primary surgery is a critical preoperative consideration, as subtotal resections likely complicate later management. This is the first time the rs2305089 SNP has been implicated in the prognosis of individuals with chordoma, suggesting that screening all patients may be instructive for risk stratification.