Lateral shelf acetabuloplasty for severe Legg–Calvé–Perthes disease in patients older than 8 years

The natural history of Legg-Calvé-Perthes disease (LCPD) in children older than 8 years is usually poor without treatment. The treatment goal is to prevent deformity and incongruity of the hip by achieving a stable spherical femoral head in a deep, congruent, sharp-edged acetabulum, with a good range of hip movement at skeletal maturity. Lateral shelf acetabuloplasty in LCPD can increase the coverage of the femoral head, benefiting the remodeling of the femoral head and acetabulum. The aim of this study was to evaluate the efficacy of lateral shelf acetabuloplasty for severe LCPD in patients older than 8 years.We evaluated 51 patients with severe LCPD who underwent shelf acetabuloplasty between 1994 and 2005. Clinical and radiological examinations were evaluated preoperatively and over a mean follow-up of 132.35 months (range 102-183 months). According to the Catterall classification, the LCPD was classified as grade II in 11 (21.6%) patients, grade III in 15 (29.4%), and grade IV in 25 (49.0%). According to the Herring classification, there were 12 (23.5%) patients in grade B, 24 (47.1%) in grade B/C, and 15 (29.4%) in grade C. The mean ages at the onset of signs and at surgery were 103.39 months and 110.78 months, respectively.By the end of follow-up, all patients had a normal passive range of hip movement without pain. The mean Iowa hip score was improved from 69.5 ± 7.28 to 91.6 ± 5.14 (P < 0.001). According to the Stulberg classification, 11 (21.6%) hips were classified as grade 1, 19 (37.3%) hips as grade 2, 14 (27.5%) hips as grade 3, and 7 (13.7%) hips as grade 4. The CE angle, Sharp angle, medial joint space ratio, epiphysis height ratio, and percentage of acetabular coverage were significantly improved by shelf acetabuloplasty (P < 0.001).We recommend shelf acetabuloplasty for severe LCPD in patients older than 8 years. The procedure yields a favorable clinical outcome and Stulberg outcome for the hip. Shelf acetabuloplasty can improve femoral head coverage and reduce subluxation of the hip, with a benefit to the biological remodeling of the femoral head within the acetabulum.