The Effect of Complications and Reoperation on Recovery Kinetics in 149 Adult Spinal Deformity Patients with 2-Year Follow-Up: An Area under the Curve Analysis

Abstract

Introduction Complication rates in adult spinal deformity (ASD) surgery are high and the effects on overall recovery are not well understood. Current methods of reporting outcomes are limited to static outcome time points perhaps diminishing the health impact of the entire recovery experience. This study aims to identify the effect of complications on the kinetics of the recovery process (recovery kinetics) by examining the effect of HRQOL over time via an area under the curve analysis (AUC). Materials and Methods A retrospective review of a multicenter, prospective ASD database. Inclusion criteria, ≥ 18 years, ASD. Complication number, type, and need for reoperation (reop) were recorded. Patients (pts) were stratified as having no complication (NOCOMP) and any complication (COMP). HRQOL collected included Oswestry Disability Index (ODI), Short Form-36 (SF-36), and Scoliosis Research Society-22 (SRS22) at baseline, 6 weeks, 1 and 2 years post-op. All HRQOL was normalized to each pts' baseline scores as a comparison relative to where the pts started. An AUC was then calculated across the entire 2 years. Standard HRQOL, normalized HRQOL, and AUC means were compared between the groups. Results A total of 149 pts were included (COMP: 84 and NOCOMP: 45). There were no significant HRQOL differences at any time point between the groups ( p > 0.05 for all). However, after normalizing the HRQOL, COMP had significantly lower SRS mental scores at 1 year (1.1 ± 0.2 vs.1.2 ± 0.3, p = 0.0002) and 2 years (1.1 ± 0.3 vs. 1.3 ± 0.4, p = 0.0003). COMP had significantly lower SRS Mental AUC than NOCOMP (3.2 ± 0.5 vs. 3.5 ± 0.6, p = 0.0023). Overall, 28 (19%) pts had a reop. There were no significant differences between any HRQOL 2-year AUC values between pts with complications requiring reop and those with no reop ( p > 0.05 for all). Conclusion Static HRQOL analysis would suggest there is no difference between complication groups. Area under the curve (AUC) analysis suggests there is a significantly protracted mental recovery phase associated with patients that have at least one complication and the addition of reop does not affect the recovery kinetics.