Predictors of Relevant Changes in Pain and Function for Adolescents With Idiopathic Scoliosis Following Surgery

Abstract

Study Design. Retrospective analysis of longitudinal data. Objective. To evaluate clinically relevant change in surgical outcomes for Adolescents with Idiopathic Scoliosis (AIS), comparing those who achieved smallest detectable change (SDC) in pain and function at 1-year post-surgery with those who did not, and to evaluate the influencing factors. Summary of Background Data. The SDC is recommended to evaluate the surgical outcomes of AIS. However, little is known about the use of SDC in AIS and its influencing factors. Materials and Methods. This was a retrospective analysis of longitudinal data from patients who underwent surgical correction at a tertiary spinal centre from 2009 to 2019. Surgical outcomes were assessed at short-term (6 wk, 6 mo) and long-term (1- and 2-years) post-surgery using the Scoliosis Research Society questionnaire (SRS-22r). The difference between “successful” (≥SDC) and “unsuccessful” (<SDC) groups was assessed using an independent t-test. Univariate and logistic regression analyses enabled the assessment of influencing factors. Results. All SRS-22r domains decreased in the short term, except for self-image and satisfaction. In the long term, self-image increased by 1.21 and function increased by 0.2, and pain decreased by 0.1. In all SRS-22r domains “successful” group had low pre-surgery scores and were statistically different to the “unsuccessful group”. The difference remained statistically significant at 1-year for most SRS-22r domains. Being older and having low pre-surgery SRS-22r scores increased the chances of achieving SDC in function at 1-year. Achieving SDC in the pain domain was significantly associated with age, sex, length of hospital stay, and SRS-22r pre-surgery scores. Conclusion. Notably, the self-image domain showed the largest change compared to other SRS-22r domains. A low pre-surgery score increases the likelihood of clinical benefit from surgery. These findings demonstrate the utility of SDC for assessing the benefits and factors that may underpin surgical benefit in AIS.