Factors associated with failure to achieve Scoliosis Research Society-22r minimal clinically important difference despite achieving optimal global alignment in adult spinal deformity surgery.

Abstract

To identify factors associated with failure to achieve the minimal clinically important difference (MCID) in the Scoliosis Research Society-22r (SRS-22r) despite achieving optimal global alignment in adult spinal deformity (ASD) surgery. This study analyzed consecutive patients who underwent ≥ 5-level fusion for ASD and achieved optimal global alignment at a minimum of 2-year follow-up. Patients were divided into two groups based on whether they reached the MCID threshold (1.05) for the SRS-22r subtotal score. Demographic, surgical, radiographic, and mechanical complication data were compared between the groups. Multivariate logistic regression analysis was performed to identify independent predictors of MCID failure. A total of 259 patients were included in this study (female, 88.0%; mean age, 69.0 years; mean follow-up duration, 36.5 months). At the final follow-up, 117 patients (45.2%) failed to achieve the SRS-22r MCID. Multivariate analysis identified a high preoperative SRS-22r pain score (odds ratio [OR] = 1.988, P = 0.003) and high preoperative self-image score (OR = 2.597, P = 0.006) as independent predictors of MCID failure. The cutoff values for preoperative pain and self-image scores were 2.50 and 1.70, respectively (area under the curve [AUC] = 0.674 for pain subdomain; AUC = 0.656 for self-image subdomain). Despite achieving optimal global alignment, nearly half of the patients (45.2%) failed to reach the MCID in the SRS-22r score. Higher preoperative SRS-22r pain and self-image scores were significant predictors of failure. Therefore, these two factors should be primary considerations in surgical decision-making to improve patient-reported outcomes.