Waistline Asymmetry Patterns and Clinical Impact in Patients with Adolescent Idiopathic Scoliosis.
Methods: Retrospective design. Objective: This study aimed to 1) classify waistline asymmetry by scoliosis type, 2) evaluate postoperative changes, and 3) assess clinical outcomes in patients with adolescent idiopathic scoliosis (AIS) using digital photography.
Background: AIS often affects physical appearance, with waistline asymmetry being particularly affected. Despite its importance, studies on waistline asymmetry, especially its variation among individuals with AIS and related postoperative outcomes, are limited.
Methods: We retrospectively analyzed the data of patients with AIS who underwent posterior fusion surgery and had a minimum of two years of follow-up. Waistline asymmetry was assessed using digital photography. The waist angle (WA), waist-height angle (WHA), and waistline depth (WLD) were measured pre- and postoperatively. Radiographic parameters and the revised 22-item Scoliosis Research Society Questionnaire (SRS-22r) were also evaluated. We categorized waistline patterns into two types based on the WLD ratio: Type R (WLD ratio < 0.5) and type L (WLD ratio > 0.5). The frequency of each waistline type was determined using the Lenke classification system. We defined severe waistline asymmetry (SWA) as WLD on one side at least twice that on the opposite side and compared its clinical outcomes with those of patients without SWA.
Results: In total, 192 patients were included in this study. Photographic and radiographic parameters significantly improved postoperatively. Pre- and postoperative waistline parameters were significantly correlated with radiographic parameters, particularly the TL/L curves. Type R was more common in lumbar modifiers A and B, whereas type L was more common in lumbar modifier C. Preoperative SWA, which was observed in 55% of patients, reduced to 11% postoperatively. Patients with postoperative SWA showed significantly higher TL/L curves and AVT-TL/L, lower L4 tilt, and lower self-image scores.
Conclusions: Postoperative residual waistline asymmetry negatively affected self-image. These data suggest that correcting the lumbar curve is crucial to improving asymmetry. Methods: Level 4.