Reciprocal Changes in Cervical Alignment After Thoracolumbar Arthrodesis for Adult Spinal Deformity.

STUDY DESIGN: Multicenter database review of consecutive adult spinal deformity (ASD) patients. OBJECTIVE: The aim of this study was to identify associations between changes in spinopelvic parameters and cervical alignment after thoracolumbar arthrodesis for ASD. SUMMARY OF BACKGROUND DATA: Reciprocal cervical changes occur after instrumented thoracic spinal arthrodesis. The timing and relationship of these changes to sagittal alignment and upper instrumented vertebra (UIV) selection are unknown. METHODS: In 171 ASD patients treated with thoracolumbar arthrodesis from 2008 to 2012, we assessed changes from baseline to 6-week, 1-year, and 2-year follow-up in C2-C7 sagittal vertical axis (SVA), T1 slope, and C2-C7 lordosis. We used multivariate models to analyze associations between these parameters and UIV selection (T9 or distal vs. proximal to T9) and changes at each time point in thoracic kyphosis (TK), lumbar lordosis (LL), C7-S1 SVA, pelvic incidence, pelvic tilt, and sacral slope. RESULTS: Two-year changes in C2-C7 SVA and T1 slope were significantly associated with baseline to 6-week changes in TK and LL and with UIV selection. Baseline to 2-year changes in C2-C7 lordosis were associated with baseline to 6-week changes in C7-S1 SVA (P = 0.004). Most changes in C2-C7 SVA occurred during the first 6 weeks postoperatively (mean 6-week change in C2-C7 SVA: 2.7 cm, 95% confidence interval [CI]: 0.7-4.7 cm; mean 2-year change in SVA: 2.3 cm, 95% CI: -0.1 to 4.6 cm). At 2 years, on average, there was decrease in C2-C7 lordosis, most of which occurred during the first 6 weeks postoperatively (mean 6-week change: -3.2°, 95% CI: -4.8° to -1.2°; mean 2-year change: -1.3°, 95% CI: - 3.2° to 0.5°). CONCLUSION: After thoracolumbar arthrodesis, reciprocal changes in cervical alignment are associated with postoperative changes in TK, LL, and C7-S1 SVA and with UIV selection. The largest changes occur during the first 6 weeks and persist during 2-year follow-up. LEVEL OF EVIDENCE: 3.

Perioperative Neurologic Complications in Adult Spinal Deformity Surgery: Incidence and Risk Factors in 564 Patients.

STUDY DESIGN: Prognostic study-case controlled. OBJECTIVE: Describe the rate of neurologic complications in adult spinal deformity surgery and describe the effect of these complications on clinical outcomes. SUMMARY OF BACKGROUND DATA: The incidence of neurologic complications and the risk factors for neurologic complications have not been reported in a large series of patients with adult spinal deformity (ASD). Existing series include a mixed patient cohort undergoing different types of spine surgery. METHODS: Patients with ASD undergoing surgery between 2008 and 2014 were analyzed. Patients with neurologic complications were identified; demographics, operative details, and radiographic and clinical outcomes were compared. A subanalysis of those with surgical and nonsurgical (e.g., stroke) neurologic complications was performed. Statistical analysis included t tests or χ tests as appropriate and a multivariate analysis. A P value of less than 0.025 was considered significant. RESULTS: A total of 564 patients met the inclusion criteria. The average age was 57 years. There were a total of 116 neurologic complications in 99 patients (17.6%). There were 88 surgical procedure-related neurologic complications in 77 patients (13.7%) and 28 nonsurgical neurologic complications in 28 patients (5.0%). The most common complications were radiculopathy (30%), motor deficits (22%), mental status changes (12%), and sensory deficits (12%). Revisions (odds ratio [OR] 1.7, 95% confidence interval [CI] 1.2-2.4) and interbody fusions (OR 2.1, 95% CI 1.4-3.2) were associated with an increased risk of neurologic complications. Decompression and osteotomies (including three-column osteotomies) did not increase the risk of neurologic complications. Patients with neurologic complications were not more likely to sustain other complications; however, they were more likely to undergo another operation during the follow-up period (OR 1.9, 95% CI 1.3-2.8). CONCLUSION: The overall incidence of neurologic complications in ASD surgery was 17.6%. The incidence of surgical neurologic complications was 13.7%. There was a higher risk of neurologic complications in revision cases and in cases in which interbody fusion was required. LEVEL OF EVIDENCE: 3.

Predicting Extended Length of Hospital Stay in an Adult Spinal Deformity Surgical Population.

STUDY DESIGN: A retrospective review of a prospective multicenter database. OBJECTIVE: The aim of this study was to identify variables associated with extended length of stay (ExtLOS) and this impact on health-related quality of life (HRQoL) scores in adult spinal deformity (ASD) patients. SUMMARY OF BACKGROUND DATA: ASD surgery is complex and associated with complications including extLOS. Although variables contributing to extLOS have been considered, specific complications and pre-disposing factors among ASD surgical patients remain to be investigated. INCLUSION CRITERIA: ASD surgical patients (age >18 years, scoliosis ≥20°, sagittal vertical axis ≥5 cm, pelvic tilt ≥25°, and/or thoracic kyphosis >60°) with complete demographic, radiographic, and HRQoL data at baseline, 6 weeks, and 2 years postoperative. ExtLOS was based on 75th percentile (≥9 days). Univariate and multivariate analyses identified predictors and evaluated effects on outcomes. Repeated-measures mixed models analyzed impact of ExtLOS on HRQoL [Oswestry Disability Index; Short Form-36 physical component summary/mental component summary; SRS22r Activity (AC), Pain (P), Appearance (AP), Satisfaction (S), Mental (M) and Total (T)]. RESULTS: Three hundred eighty patients met inclusion criteria: 105 (27.6%) had extLOS (≥9 days) and 275 (72.4%) did not. Average LOS was 8 days (range: 1-30 days). Age [odds ratio (OR) 1.04], no. of levels fused (OR 1.12), no. of infections (OR 2.29), no. of neurologic complications (OR 2.51), Charlson Comorbidity Index Score (CCI) predicted ExtLOS (OR 3.92), and no. of intraop complications predicted ExtLOS (OR 3.56). ExtLOS patients had more intracardiopulmonary (pleural effusion: 1.9% vs. 0%) and operative complications (dural tear: 13.3% vs. 5.1%; excessive blood loss: 18% vs. 5.8%) (P < 0.022). At 2 years, both groups of patients experienced an overall improvement in all HRQoL scores (P < 0.001). ExtLOS patients had significantly less overall improvement in all HRQoLs (P < 0.01) except for MCS (P = 0.17) and SRS M (P = 0.08). CONCLUSION: Extended LOS of ASD patients is affected by comorbidities (higher CCI) and number of intraoperative, but not peri-operative, complications. All patients improved overall in HRQoL scores, but extended LOS patients improved less overall at 2 years in comparison. LEVEL OF EVIDENCE: 3.