EP1.94 Modified capsular arthroplasty for developmental hip dislocation in young patients: mid- to long-term outcomes

Abstract

Abstract Purpose This study aimed to evaluate the mid- to long-term clinical and radiographic outcomes of the modified Codivilla-Hey Groves-Colonna capsular arthroplasty in young patients with developmental dislocation of the hip (DDH), and to identify risk factors associated with inferior results. Methods A retrospective review was performed on 119 patients (121 hips) who underwent the modified capsular arthroplasty between June 2012 and June 2025. All patients had a minimum follow-up of one year, with a mean follow-up exceeding six years. Functional outcomes were assessed using the modified Harris Hip Score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the 12-item International Hip Outcome Tool (iHOT-12). Radiographic outcomes were graded according to the Tönnis osteoarthritis grade and Severin classification. Logistic regression analysis was conducted to identify predictors of inferior outcomes. Results At mid- to long-term follow-up, the mean functional scores demonstrated that hip function remained generally stable compared with preoperative status, although modest declines were observed relative to early postoperative results. The majority of patients continued to report acceptable pain relief and functional capacity. The iHOT-12 score showed sustained improvement over baseline, indicating lasting benefits in quality of life and sports-related function. Radiographically, over half of the hips achieved superior outcomes (Tönnis grade < 2 and Severin class < III). Capsular quality and capsular thickness were confirmed as independent risk factors for inferior radiographic outcomes. Joint stiffness remained the most common complication, while the incidence of femoral head necrosis was notably low in later years of the study. Conclusion The modified capsular arthroplasty offers durable and acceptable mid- to long-term outcomes for carefully selected young patients with DDH. Although mild functional decline may occur over time compared with short-term follow-up, the procedure effectively preserves hip function, alleviates pain, and delays the need for total hip arthroplasty. Strict adherence to indications—particularly favorable capsular quality and thickness—is essential for optimizing long-term results.