International Orthopaedics - 2026-07-06 - Journal Article
Comparison of subtrochanteric varus osteotomy and shelf acetabuloplasty in fragmentation-stage (Waldenström stage II) Legg-Calvé-Perthes disease: a prospective randomized study.
Abd El-Hameed H, Okasha KI, Hegazy MM, El-Barbary HM, Ali MY, Ahmed AM
Topics
Key Takeaway
STVO and shelf acetabuloplasty produced equivalent clinical outcomes (81.2% good in each group) in Waldenström stage II LCPD, but STVO caused clinically significant LLD (>1.5 cm) in 43.8% of patients versus 0% in the shelf group.
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Summary
This prospective RCT randomized 32 children with fragmentation-stage (Waldenström stage II) LCPD to subtrochanteric varus osteotomy (n=16) or shelf acetabuloplasty (n=16) to compare clinical and radiographic containment outcomes. Both groups achieved 81.2% good outcomes by modified Sundt criteria, with significant improvement in CEA, Sharp's angle, and medial joint space ratio in each group and no statistically significant between-group differences after ANCOVA adjustment. STVO produced clinically significant LLD (>1.5 cm) in 43.8% of patients versus 0% in the shelf group, and exploratory Stulberg analysis in the subgroup reaching remodeling stage suggested a possible sphericity advantage with STVO that cannot be confirmed at this follow-up.
Key Limitation
The ~2-year follow-up precedes skeletal maturity in all patients, making definitive Stulberg classification invalid and leaving the most clinically important outcome—final femoral head sphericity—unresolved.
Original Abstract
PURPOSE
Optimal containment in fragmentation stage (Waldenström stage II) of Legg-Calvé-Perthes disease (LCPD) remains controversial. This study compared the clinical and radiographic outcomes of subtrochanteric femoral varus osteotomy (STVO) versus shelf acetabuloplasty in children with fragmentation stage (Waldenström stage II) of LCPD.
METHODS
This prospective randomized clinical trial included 32 children (32 hips) with LCPD in fragmentation stage (Waldenström stage II), treated between April 2022 and June 2024. Patients were randomized into two groups: STVO (n = 16) and shelf acetabuloplasty (n = 16). The primary outcome was clinical outcome at final follow-up assessed using the modified Sundt criteria. Secondary outcomes included containment radiographic parameters, interim femoral head sphericity using the Stulberg classification, leg length discrepancy (LLD), and complications. Mean follow-up duration was 25.1 ± 1.8 months in the STVO group and 26.1 ± 2.0 months in the shelf acetabuloplasty group.
RESULTS
Both procedures resulted in significant clinical and radiographic improvement. Good clinical outcomes were achieved in 81.2% of hips in each group, with no poor outcomes. At final follow-up, the mean center-edge angle (CEA) increased significantly in both groups, reflecting improved lateral femoral head coverage. Sharp's angle decreased significantly in both groups, indicating improved acetabular morphology. Both groups demonstrated a significant reduction in the medial joint space ratio, indicating improved containment. After adjustment for baseline values using ANCOVA, no statistically significant between-group differences were identified. Among hips that had reached the remodeling stage, exploratory analysis suggested a higher proportion of favorable interim Stulberg outcomes (I-II) in the STVO group; however, interpretation is limited by the small subgroup size, differential progression to remodeling, and the use of a classification system originally intended for assessment at skeletal maturity. Clinically significant LLD (> 1.5 cm) occurred in 43.8% of STVO patients and in none of the shelf group. Complications were minor and comparable.
CONCLUSION
STVO and shelf acetabuloplasty yield comparable short- to mid-term clinical outcomes in fragmentation stage (Waldenström stage II) of LCPD. However, STVO was associated with a substantially higher incidence of clinically significant leg length discrepancy, whereas shelf acetabuloplasty preserved limb length. Exploratory analyses suggested a possible advantage of STVO regarding interim femoral head sphericity. These findings should not be interpreted as evidence of superiority, and require confirmation at skeletal maturity.