Identification of decision criteria for revision surgery among patients with proximal junctional failure after surgical treatment of spinal deformity.

STUDY DESIGN Multicenter, retrospective, consecutive case series. OBJECTIVE This study aims to identify demographic and radiographical characteristics that influence the decision to perform revision surgery among patients with proximal junctional failure (PJF). SUMMARY OF BACKGROUND DATA Revision rates after PJF remain relatively high, yet the decision criteria for performing revision surgical procedures are not uniform and vary by surgeon. A better understanding of the factors that impact the decision to perform revision surgery is important in order to improve efficiency of surgical treatment of adult spinal deformity. METHODS A cohort of 57 patients with PJF was identified retrospectively from 1218 consecutive patients with adult spinal deformity. PJF was identified on the basis of 10° postoperative increase in kyphosis between upper instrumented vertebra (UIV) and UIV +2, along with 1 or more of the following: fracture of the vertebral body of UIV or UIV +1, posterior osseoligamentous disruption, or pullout of instrumentation at the UIV. Univariate statistical analysis was performed using t tests and Fisher exact tests. Multivariate analysis was performed using logistic regression. RESULTS Twenty-seven (47.4%) patients underwent revision surgery within 6 months of the index operation. Regression results revealed that patients with combined posterior/anterior approaches at index were significantly more likely to undergo revision (P = 0.001) as were patients with more extreme proximal junctional kyphosis angulation (P = 0.034). Patients sustaining trauma were also significantly more likely to undergo revision (P = 0.019). Variables approaching but not reaching significance as predictors of revision included female sex (P = 0.066) and higher sagittal vertical axis (SVA) (P = 0.090). CONCLUSION The decision to perform revision surgery is complicated and varies by surgeon. Factors that seem to influence this decision include traumatic etiology of PJF, severity of proximal junctional kyphosis angulation, higher SVA, and female sex. Factors that were expected to influence revision but had no statistical effect included soft tissue versus bony mode of failure, age, levels fused, and upper thoracic versus thoracolumbar proximal junction.