Trajectory-Based Classification of Recovery in Sensorimotor Complete Traumatic Cervical Spinal Cord Injury.

OBJECTIVE: To test the hypothesis that sensorimotor complete traumatic cervical spinal cord injury is a heterogenous clinical entity comprising several subpopulations that follow fundamentally different trajectories of neurologic recovery. METHODS: We analyzed demographic and injury data from 655 patients who were pooled from 4 prospective longitudinal multicenter studies. Group based trajectory modeling was applied to model neurologic recovery trajectories over the initial 12-months postinjury and to identify predictors of recovery trajectories. Neurologic outcomes included: Upper Extremity Motor Score, Total Motor Scores and AIS grade improvement. RESULTS: The analysis identified 3 distinct trajectories of neurologic recovery. These clinical courses included: (1) Marginal recovery trajectory: characterized by minimal or no improvement in motor strength or change in AIS grade status (remained grade A); (2) Moderate recovery trajectory: characterized by low baseline motor scores that improved approximately 13 points; or AIS conversion of one grade point; (3) Good recovery trajectory: characterized by baseline motor scores in the upper quartile that improved to near maximum values within 3 months of injury. Patients following the moderate or good recovery trajectories were of younger age, had more caudally located injuries, a higher degree of preserved motor and sensory function at baseline examination and exhibited a greater extent of motor and sensory function in the zone of partial preservation. CONCLUSION: Cervical complete SCI can be classified into one of 3 distinct subpopulations with fundamentally different trajectories of neurologic recovery. This study defines unique clinical phenotypes based on potential for recovery, rather than baseline severity of injury alone. This approach may prove beneficial in clinical prognostication and in the design and interpretation of clinical trials in SCI.

Acute Adverse Events After Spinal Cord Injury and Their Relationship to Long-term Neurologic and Functional Outcomes: Analysis From the North American Clinical Trials Network for Spinal Cord Injury.

OBJECTIVES: There are few contemporary, prospective multicenter series on the spectrum of acute adverse events and their relationship to long-term outcomes after traumatic spinal cord injury. The goal of this study is to assess the prevalence of adverse events after traumatic spinal cord injury and to evaluate the effects on long-term clinical outcome. DESIGN: Multicenter prospective registry. SETTING: Consortium of 11 university-affiliated medical centers in the North American Clinical Trials Network. PATIENTS: Eight-hundred one spinal cord injury patients enrolled by participating centers. INTERVENTIONS: Appropriate spinal cord injury treatment at individual centers. MEASUREMENTS AND MAIN RESULTS: A total of 2,303 adverse events were recorded for 502 patients (63%). Penalized maximum logistic regression models were fitted to estimate the likelihood of neurologic recovery (ASIA Impairment Scale improvement ≥ 1 grade point) and functional outcomes in subjects who developed adverse events at 6 months postinjury. After accounting for potential confounders, the group that developed adverse events showed less neurologic recovery (odds ratio, 0.55; 95% CI, 0.32-0.96) and was more likely to require assisted breathing (odds ratio, 6.55; 95% CI, 1.17-36.67); dependent ambulation (odds ratio, 7.38; 95% CI, 4.35-13.06) and have impaired bladder (odds ratio, 9.63; 95% CI, 5.19-17.87) or bowel function (odds ratio, 7.86; 95% CI, 4.31-14.32) measured using the Spinal Cord Independence Measure subscores. CONCLUSIONS: Results from this contemporary series demonstrate that acute adverse events are common and are associated with worsened long-term outcomes after traumatic spinal cord injury.

Association of Pneumonia, Wound Infection, and Sepsis with Clinical Outcomes after Acute Traumatic Spinal Cord Injury.

Pneumonia, wound infections, and sepsis (PWS) are the leading causes of acute mortality after traumatic spinal cord injury (SCI). However, the impact of PWS on neurological and functional outcomes is largely unknown. The present study analyzed participants from the prospective North American Clinical Trials Network (NACTN) registry and the Surgical Timing in Acute SCI Study (STASCIS) for the association between PWS and functional outcome (assessed as Spinal Cord Independence Measure subscores for respiration and indoor ambulation) at 6 months post-injury. Neurological outcome was analyzed as a secondary end-point. Among 1299 participants studied, 180 (14%) developed PWS during the acute admission. Compared with those without PWS, participants with PWS were mostly male (76% vs. 86%; p = 0.007), or presented with mostly American Spinal Injury Association Impairment Scale (AIS) grade A injury (36% vs. 61%; p < 0.001). There were no statistical differences between participants with or without PWS with respect to time from injury to surgery, and administration of steroids. Dominance analysis showed injury level, baseline AIS grade, and subject pre-morbid medical status collectively accounted for 77.7% of the predicted variance of PWS. Regression analysis indicated subjects with PWS demonstrated higher odds for respiratory (odds ratio [OR] 3.91, 95% confidence interval [CI]: 1.42-10.79) and ambulatory (OR 3.94, 95% CI: 1.50-10.38) support at 6 month follow-up in adjusted analysis. This study has shown an association between PWS occurring during acute admission and poorer functional outcomes following SCI.

Cervical Versus Thoracolumbar Spinal Deformities: A Comparison of Baseline Quality-of-Life Burden.

STUDY DESIGN: Retrospective analysis of 2 prospectively collected multicenter databases, one for cervical deformity (CD) and the other for general adult spinal deformity. OBJECTIVE: To investigate the relative quality-of-life and disability burden in patients with uncompensated cervical, thoracolumbar, or cervical and thoracolumbar deformities. SUMMARY OF BACKGROUND DATA: The relative quality-of-life burden of cervical and thoracolumbar deformities have never been compared with each other. This may have significant implications when deciding on the appropriate treatment intervention for patients with combined thoracolumbar and cervical deformities. METHODS: When defining CD C2-C7 sagittal vertical axis (SVA)>4 cm was used while a C7-S1 SVA>5 cm was used to defined thoracolumbar deformity. Patients with both SVA criteria were defined as "combined." Primary analysis compared patients in the different groups by demographic, comorbidity data, and quality-of-life scores [EuroQOL 5 dimensions questionnaire (EQ-5D)] using t tests. Secondary analysis matched deformity groups with propensity scores matching based on baseline EQ-5D scores. Differences in disease-specific metrics [the Oswestry Disability Index, Neck Disability Index, modified Japanese Orthopaedic Association questionnaire (mJOA)] were analyzed using analysis of variance tests and post hoc analysis. RESULTS: In total, 212 patients were included in our analysis. Patients with CD only had less neurological deficits (mJOA: 14.6) and better EQ-5D (0.746) scores compared with patients with combined deformities (11.9, 0.716), all P<0.05. Regarding propensity score-matched deformity cohorts, 99 patients were matched with similar quality-of-life burden, 33 per deformity cohort. CD only patients had fewer comorbidities (1.03 vs. 2.12 vs. 2.70; P<0.001), whereas patients with combined deformity had more baseline neurological impairment compared with CD only patients (mJOA: 12.00 vs. 14.25; P=0.050). CONCLUSIONS: Combined deformity patients were associated with the lowest quality-of-life and highest disability. Furthermore, regarding deformity cohorts matched by similar baseline quality-of-life status (EQ-5D), patients with combined deformities were associated with significantly worse neurological impairments. This finding implies that quality of life may not be a direct reflection of a patient's disability status, especially in patients with combined cervical and thoracolumbar deformities. LEVEL OF EVIDENCE: Level III.

Predictive model for distal junctional kyphosis after cervical deformity surgery.

BACKGROUND CONTEXT: Distal junctional kyphosis (DJK) is a primary concern of surgeons correcting cervical deformity. Identifying patients and procedures at higher risk of developing this condition is paramount in improving patient selection and care. PURPOSE: The present study aimed to develop a risk index for DJK development in the first year after surgery. STUDY DESIGN/SETTING: This is a retrospective review of a prospective multicenter cervical deformity database. PATIENT SAMPLE: Patients over the age of 18 meeting one of the following deformities were included in the study: cervical kyphosis (C2-7 Cobb angle>10°), cervical scoliosis (coronal Cobb angle>10°), positive cervical sagittal imbalance (C2-C7 sagittal vertical axis (SVA)>4 cm or T1-C6>10°), or horizontal gaze impairment (chin-brow vertical angle>25°). OUTCOME MEASURES: Development of DJK at any time before 1 year. METHODS: Distal junctional kyphosis was defined by both clinical diagnosis (by enrolling surgeon) and post hoc identification of development of an angle<-10° from the end of fusion construct to the second distal vertebra, as well as a change in this angle by <-10° from baseline. Conditional Inference Decision Trees were used to identify factors predictive of DJK incidence and the cut-off points at which they have an effect. A conditional Variable-Importance table was constructed based on a non-replacement sampling set of 2,000 Conditional Inference Trees. Twelve influencing factors were found; binary logistic regression for each variable at significant cutoffs indicated their effect size. RESULTS: Statistical analysis included 101 surgical patients (average age: 60.1 years, 58.3% female, body mass index: 30.2) undergoing long cervical deformity correction (mean levels fused: 7.1, osteotomy used: 49.5%, approach: 46.5% posterior, 17.8% anterior, 35.7% combined). In 2 years after surgery, 6% of patients were diagnosed with clinical DJK; however, 23.8% of patients met radiographic definition for DJK. Patients with neurologic symptoms were at risk of DJK (odds ratio [OR]: 3.71, confidence interval [CI]: 0.11-0.63). However, no significant relationship was found between osteoporosis, age, and ambulatory status with DJK incidence. Baseline radiographic malalignments were the most numerous and strong predictors for DJK: (1) C2-T1 tilt>5.33 (OR: 6.94, CI: 2.99-16.14); (2) kyphosis<-50.6° (OR: 5.89, CI: 0.07-0.43); (3) C2-C7 lordosis<-12° (OR: 5.7, CI: 0.08-0.41); (4) T1 slope minus cervical lordosis>36.4 (OR: 5.6, CI: 2.28-13.57); (5) C2-C7 SVA>56.3° (OR: 5.4, CI: 2.20-13.23); and (6) C4_Tilt>56.7 (OR: 5.0, CI: 1.90-13.1). Clinically, combined approaches (OR: 2.67, CI: 1.21-5.89) and usage of Smith-Petersen osteotomy (OR: 2.55, CI: 1.02-6.34) were the most important predictors of DJK. CONCLUSIONS: In a surgical cohort of patients with cervical deformity, we found a 23.8% incidence of DJK. Different procedures and patient malalignment predicted incidence of DJK up to 1 year. Preoperative T1 slope-cervical lordosis, cervical kyphosis, SVA, and cervical lordosis all strongly predicted DJK at specific cut-off points. Knowledge of these factors will potentially help direct future study and strategy aimed at minimizing this potentially dramatic occurrence.

Cost-utility analysis of cervical deformity surgeries using 1-year outcome.

BACKGROUND CONTEXT: Cost-utility analysis, a special case of cost-effectiveness analysis, estimates the ratio between the cost of an intervention to the benefit it produces in number of quality-adjusted life years. Cervical deformity correction has not been evaluated in terms of cost-utility and in the context of value-based health care. Our objective, therefore, was to determine the cost-utility ratio of cervical deformity correction. STUDY DESIGN: This is a retrospective review of a prospective, multicenter cervical deformity database. Patients with 1-year follow-up after surgical correction for cervical deformity were included. Cervical deformity was defined as the presence of at least one of the following: kyphosis (C2-C7 Cobb angle >10°), cervical scoliosis (coronal Cobb angle >10°), positive cervical sagittal malalignment (C2-C7 sagittal vertical axis >4 cm or T1-C6 >10°), or horizontal gaze impairment (chin-brow vertical angle >25°). Quality-adjusted life years were calculated by both EuroQol 5D (EQ5D) quality of life and Neck Disability Index (NDI) mapped to short form six dimensions (SF6D) index. Costs were assigned using Medicare 1-year average reimbursement for: 9+ level posterior fusions (PF), 4-8 level PF, 4-8 level PF with anterior fusion (AF), 2-3 level PF with AF, 4-8 level AF, and 4-8 level posterior refusion. Reoperations and deaths were added to cost and subtracted from utility, respectively. Quality-adjusted life year per dollar spent was calculated using standardized methodology at 1-year time point and subsequent time points relying on maintenance of 1-year utility. RESULTS: Eighty-four patients (average age: 61.2 years, 60% female, body mass index [BMI]: 30.1) were analyzed after cervical deformity correction (average levels fused: 7.2, osteotomy used: 50%). Costs associated with index procedures were 9+ level PF ($76,617), 4-8 level PF ($40,596), 4-8 level PF with AF ($67,098), 4-8 level AF ($31,392), and 4-8 level posterior refusion ($35,371). Average 1-year reimbursement of surgery was $55,097 at 1 year with eight revisions and three deaths accounted for. Cost per quality-adjusted life year (QALY) gained to 1-year follow-up was $646,958 by EQ5D and $477,316 by NDI SF6D. If 1-year benefit is sustained, upper threshold of cost-effectiveness is reached 3-4.5 years after intervention. CONCLUSIONS: Medicare 1-year average reimbursement compared with 1-year QALYdescribed $646,958 by EQ5D and $477,316 by NDI SF6D. Cervical deformity surgeries reach accepted cost-effectiveness thresholds when benefit is sustained 3-4.5 years. Longer follow-up is needed for a more definitive cost-analysis, but these data are an important first step in justifying cost-utility ratio for cervical deformity correction.

In-Hospital Complications and Resource Utilization Following Lumbar Spine Surgery in Patients with Parkinson Disease: Evaluation of the National Inpatient Sample Database.

BACKGROUND: Previous reports suggest that patients with Parkinson disease (PD) have elevated rates of complications following spine surgery; however, these reports are limited by small patient series. In this study, we used the National Inpatient Sample (NIS) database to compare in-hospital complications following elective lumbar spine surgery in patients with a diagnosis of PD and patients without PD. METHODS: The NIS database was accessed to identify patients with PD and those without PD who underwent lumbar spine surgery. All patients identified had a diagnosis code consistent with degenerative lumbar spine pathology. The patients were evaluated for the presence or absence of PD and divided into 4 lumbar spine procedure groups: decompression alone, lateral fusion, posterior fusion, and anterior fusion technique. Propensity score matching (PSM) was performed for the PD versus non-PD patients in each procedure group to control for confounding demographic variables, and in-hospital complications were compared between the 2 groups. RESULTS: Between 2001 and 2012, a total of 613,522 lumbar spine surgery patient episodes were identified, of which 4492 (0.7%) involved a diagnosis of PD. Following PSM for patient age, sex, and race, the patients with PD were at increased risk for acute postoperative hemorrhagic anemia, increased blood transfusion requirements, and increased genitourinary, neurologic, and cardiac complications compared with the patients without PD. CONCLUSIONS: PSM analysis of the NIS database demonstrated that patients with PD are at increased risk for acute in-hospital complications and greater blood transfusion requirements than those without PD. Surgeons should be aware of the increased risks and differing requirements when treating spinal pathology in patients with PD.

Does MIS Surgery Allow for Shorter Constructs in the Surgical Treatment of Adult Spinal Deformity?

Background: The length of construct can potentially influence perioperative risks in adult spinal deformity (ASD) surgery. A head-to-head comparison between open and minimally invasive surgery (MIS) techniques for treatment of ASD has yet to be performed. Objective: To examine the impact of MIS approaches on construct length and clinical outcomes in comparison to traditional open approaches when treating similar ASD profiles. Methods: Two multicenter databases for ASD, 1 involving MIS procedures and the other open procedures, were propensity matched for clinical and radiographic parameters in this observational study. Inclusion criteria were ASD and minimum 2-year follow-up. Independent t -test and chi-square test were used to evaluate and compare outcomes. Results: A total of 1215 patients were identified, with 84 patients matched in each group. Statistical significance was found for mean levels fused (4.8 for circumferential MIS [cMIS] and 10.1 for open), mean interbody fusion levels (3.6 cMIS and 2.4 open), blood loss (estimated blood loss 488 mL cMIS and 1762 mL open), and hospital length of stay (6.7 days cMIS and 9.7 days open). There was no significant difference in preoperative radiographic parameters or postoperative clinical outcomes (Owestry Disability Index and visual analog scale) between groups. There was a significant difference in postoperative lumbar lordosis (43.3° cMIS and 49.8° open) and pelvic incidence-lumbar lordosis correction (10.6° cMIS and 5.2° open) in the open group. There was no significant difference in reoperation rate between the 2 groups. Conclusion: MIS techniques for ASD may reduce construct length, reoperation rates, blood loss, and length of stay without affecting clinical and radiographic outcomes when compared to a similar group of patients treated with open techniques.

The Clinical Correlation of the Hart-ISSG Proximal Junctional Kyphosis Severity Scale With Health-Related Quality-of-life Outcomes and Need for Revision Surgery.

STUDY DESIGN: Retrospective analysis of prospective data. OBJECTIVE: Evaluate the utility of the Hart-International Spine Study Group proximal junctional kyphosis severity scale (Hart-ISSG PJKSS). SUMMARY OF BACKGROUND DATA: Proximal junctional kyphosis (PJK) and failure (PJF) are well-described complications after long-segment instrumentation. The Hart-ISSG PJKSS was recently developed and incorporates neurological deficit, pain, instrumentation issues, degree of kyphosis, presence of fracture, and level of upper-most instrumented vertebrae. METHODS: All adult spinal deformity patients with PJK or PJF were identified from two academic centers over a 7-year period. Health-related quality-of-life (HRQOL) outcomes were prospectively collected: Oswestry Disability Index (ODI), visual analogue scale (VAS) pain, SF-36 questionnaire, and SRS-30 questionnaire. Patients were retrospectively assigned Hart-ISSG PJKSS scores. Correlation between the Hart-ISSG PJKSS and outcomes was assessed with linear regression, Pearson correlation coefficients, and χ² analysis. RESULTS: A total of 184 cases were included; 21.2% were men and mean age was 65.0 years. Weakness and/or myelopathy were present in 11.4% of patients and 88.6% had pain. Instrumentation issues occurred in 44.0% and 64.1% had PJK-associated fractures. PJK occurred in the upper thoracic spine in 21.7% of cases. Mean PJKSS score was 5.9. The Hart-ISSG PJKSS was significantly and strongly associated with ODI (P < 0.001, r = 0.611), VAS pain (P < 0.001, r = 0.676), SRS-30 function (P < 0.001, r = -0.401), SRS-30 mental health (P < 0.001, r = -0.592), SRS-30 self-image (P < 0.001, r = -0.511), SRS-30 satisfaction (P < 0.001, r = -0.531), and SRS-30 pain (P < 0.001, r = -0.445). Higher scores were associated with higher proportion of patients undergoing revision surgery (P < 0.001); scores of 9 to 11 and 12 to 15 underwent revision 96.0% and 100.0% of the time, respectively. CONCLUSION: The Hart-ISSG PJKSS was strongly correlated with validated functional outcomes and higher scores were associated with higher rates of revision surgery. The Hart-ISSG PJKSS may be a useful clinical tool in the treatment of patient with PJK. LEVEL OF EVIDENCE: 3.

Effectiveness of spinal fusion versus structured rehabilitation in chronic low back pain patients with and without isthmic spondylolisthesis: a systematic review.

STUDY DESIGN: Systematic review. OBJECTIVE: To determine if the presence of isthmic spondylolisthesis modifies the effect of treatment (fusion vs. multidimensional supervised rehabilitation) in patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: Results of spinal surgery for CLBP are variable. It is unclear whether patients with CLBP and isthmic spondylolisthesis have more success with surgery versus a multidimensional supervised rehabilitation program when compared with those with CLBP but without spondylolisthesis. METHODS: A systematic search was conducted in MEDLINE and the Cochrane Collaboration Library for articles published through January 2011. Randomized controlled trials (RCTs) were included that compared spine fusion versus multidimensional supervised rehabilitation in patients with and without isthmic spondylolisthesis. Standardized mean differences (SMDs) and risk differences were calculated for common outcomes, and then compared to determine potential heterogeneity of treatment effect. The final strength of the body of literature was expressed as "high," "moderate," or "low" confidence that the evidence reflects the true effect. RESULTS: No studies were found that directly compared the two subgroups. Three RCTs compared fusion with supervised nonoperative care in patients with CLBP without isthmic spondylolisthesis; one RCT evaluated these treatments in patients with isthmic spondylolisthesis. There were study differences in patient characteristics, type of fusion, the nature of the rehabilitation, outcomes assessed, and length of follow-up. The SMDs for pain in favor of fusion were modest at 2 years for those without isthmic spondylolisthesis, but large in favor of fusion for those with isthmic spondylolisthesis compared with rehabilitation. Similarly, the SMDs for function in patients without isthmic spondylolisthesis compared with rehabilitation was small at 2 years, but appreciably higher in favor of fusion in patients with isthmic spondylolisthesis. CONCLUSION: The overall strength of evidence evaluating whether the presence of isthmic spondylolisthesis modifies the effect of fusion compared with rehabilitation patients with CLBP is "low." Fusion should be considered for patients with low back pain and isthmic spondylolisthesis who have failed nonoperative treatment. CLINICAL RECOMMENDATIONS: We recommend considering fusion for patients with isthmic spondylolisthesis and lower back pain who have failed nonoperative treatment. RECOMMENDATION: Weak.

A phase I/IIa clinical trial of a recombinant Rho protein antagonist in acute spinal cord injury.

Multiple lines of evidence have validated the Rho pathway as important in controlling the neuronal response to growth inhibitory proteins after central nervous system (CNS) injury. A drug called BA-210 (trademarked as Cethrin(®)) blocks activation of Rho and has shown promise in pre-clinical animal studies in being used to treat spinal cord injury (SCI). This is a report of a Phase I/IIa clinical study designed to test the safety and tolerability of the drug, and the neurological status of patients following the administration of a single dose of BA-210 applied during surgery following acute SCI. Patients with thoracic (T2-T12) or cervical (C4-T1) SCI were sequentially recruited for this dose-ranging (0.3 mg to 9 mg Cethrin), multi-center study of 48 patients with complete American Spinal Injury Association assessment (ASIA) A. Vital signs; clinical laboratory tests; computed tomography (CT) scans of the spine, head, and abdomen; magnetic resonance imaging (MRI) of the spine, and ASIA assessment were performed in the pre-study period and in follow-up periods out to 1 year after treatment. The treatment-emergent adverse events that were reported were typical for a population of acute SCI patients, and no serious adverse events were attributed to the drug. The pharmacokinetic analysis showed low levels of systemic exposure to the drug, and there was high inter-patient variability. Changes in ASIA motor scores from baseline were low across all dose groups in thoracic patients (1.8±5.1) and larger in cervical patients (18.6±19.3). The largest change in motor score was observed in the cervical patients treated with 3 mg of Cethrin in whom a 27.3±13.3 point improvement in ASIA motor score at 12 months was observed. Approximately 6% of thoracic patients converted from ASIA A to ASIA C or D compared to 31% of cervical patients and 66% for the 3-mg cervical cohort. Although the patient numbers are small, the observed motor recovery in this open-label trial suggests that BA-210 may increase neurological recovery after complete SCI. Further clinical trials with Cethrin in SCI patients are planned, to establish evidence of efficacy.

Pain and disability determine treatment modality for older patients with adult scoliosis, while deformity guides treatment for younger patients.

STUDY DESIGN: Multi-center, retrospective review. OBJECTIVE: Identify age associated clinical and radiographic features correlating with AS treatment. SUMMARY OF BACKGROUND DATA: Little information exists about factors determining treatment for adult scoliosis (AS). Existing studies have not evaluated age stratified differences. METHODS: Multicenter, retrospective review of 290 patients treated for AS. Patients divided into operative (OP) or nonoperative (NON), and age stratified into 3 groups (G1 = <50 years, G2 = 50-65 years, G3 = >65 years). Demographic and spinopelvic radiographic parameters evaluated. Health-related quality of life (HRQL) measures included SRS-22, Oswestry Disability Index (ODI), visual analog pain scale. RESULTS: Treatment groups (OP, n = 137; NON, n = 153) demonstrated similar age (OP = 52.7 years; NON = 55.5 years; P > 0.05) and comorbidities. OP had larger thoracic curves than NON (OP = 51 degrees, NON = 45 degrees; P < 0.05). OP had worse HRQL scores than NON (SRS = 2.95 vs. 3.12, P < 0.05; ODI = 33.4 vs. 28.7, P < 0.05; visual analog pain scale = 6.9 vs. 5.6, P < 0.05, respectively). Age stratification of OP demonstrated larger curves in G1 and G2 versus G3, progressively worsening sagittal imbalance in older age groups, and worse HRQL scores in G3 versus G1 and G2. Age stratification of NON demonstrated worsening sagittal imbalance with age, however, other radiographic values and HRQL scores were similar between all NON age groups. Treatment stratification of age groups demonstrated G1-OP had greater deformity than G1-NON (mean thoracic curve: G1-OP = 53 degrees, G1-NON = 43 degrees; P < 0.05) but similar HRQL values. Whereas G2 and G3-OP had similar radiographic coronal and sagittal values as G2 and G3-NON, but worse HRQL scores. CONCLUSION: Counter to previous reports, age, comorbidities, and sagittal balance did not influence treatment modality for AS. Operative treatment for younger patients was driven by increased coronal plane deformity. Conversely, pain and disability mandated treatment for older patients, independent of radiographic measures. These findings suggest that AS patients do not become uniformly disabled with age, and that disability can not be solely predicted by radiographic findings. These data should be considered when considering treatment for AS.