Recovery Kinetics of Radiographic and Implant-Related Revision Patients Following Adult Spinal Deformity Surgery

Abstract

Prior studies have observed similar health-related quality of life (HRQL) in revisions and nonrevision (NR) patients following adult spinal deformity (ASD) correction. However, a novel comparison approach may allow better comparisons in spine outcomes groups. To determine if ASD revisions for radiographic and implant-related complications undergo a different recovery than NR patients. Inclusion: ASD patients with complete HRQL (Oswestry Disability Index, Short-Form-36 version 2 (SF-36), Scoliosis Research Society [SRS]-22) at baseline, 6 wk, 1 yr, 2 yr. Generated revision groups: nonrevision (NR), revised-complete data (RC; with follow-up 2 yr after revision), and revised-incomplete data (RI; without 2-yr follow-up after revision). In a traditional analysis, analysis of variance (ANOVA) compared baseline HRQLs to follow-up changes. In a novel approach, integrated health state was normalized at baseline using area under curve analysis before ANOVA t-tests compared follow-up statuses. Two hundred fifty-eight patients were included with 50 undergoing reoperations (19.4%). Rod fractures (n=15) and proximal joint kyphosis (n=9) were most common. In standard HRQL analysis, comparing RC index surgery and RC revision surgery HRQLS revealed no significant differences throughout the 2-yr follow-up from either the initial index or revision procedure. Using normalized HRQL/integrated health state, RI displayed worse scores in SF-36 Physical Component Score, SRS activity, and SRS appearance relative to NR (P<.05), indicating less improvement over the 2-yr period. RC were significantly worse than RI in SF-36 Mental Component Score, SRS mental, SRS satisfaction, and SRS total (P<.05). ASD patients indicated for revisions for radiographic and implant-related complications differ significantly in their overall 2-yr recovery compared to NR, using a normalized integrated health state method. Traditional methods for analyzing revision patients' recovery kinetics may overlook delayed improvements.