Lateral shelf acetabuloplasty for severe Legg-Calvé-Perthes disease in patients older than 8 years: A mean eleven-year follow-up

Abstract

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.

Conflict of interest statement

The authors report no conflicts of interest.

Figures

Figure 1

(A) The preoperative Wiberg center–edge angle = ∠abc angle; (B) The postoperative Wiberg center–edge angle = ∠abc angle; (C) Epiphysis height of femoral head ratio between the operated hip versus the contralateral hip (b1/b2); (D) The preoperative Sharp's angle = ∠abc angle, and the postoperative Sharp angle = ∠abd angle.

Figure 2

(A) Medial joint space distance (the distance from the deepest point of the teardrop to the medial femoral head) ratio of the operated hip versus the nonoperated hip (a1/a2); (B) Percentage of acetabular coverage (the ratio of the distance between the most lateral point of acetabulum and the most medial point of femoral epiphysis versus that between the most lateral point of proximal femoral epiphysis and medial point of proximal femoral epiphysis), preoperative percentage of acetabular coverage = cd/bd, and postoperative percentage of acetabular coverage = ad/bd.

Figure 3

Radiographs of a 10-year-old boy, with a history of pain in the left hip and limp. There was no history of injury and his general health was otherwise normal. (A) Anteroposterior radiographs of the pelvis at the time of diagnosis with the hip in Herring B and Catterall group II. (B) Anteroposterior radiographs immediately after a shelf acetabuloplasty. (C) Anteroposterior radiograph at follow-up showing that the hip was classified as Herring B/C and Catterall group IV. (D) Anteroposterior radiographs at the follow-up of 9 years indicating that there was a good remodeling of the femoral head with the hip classified as Stulberg II.

Figure 4

Radiographs of an 8-year-old boy, with a 10-month history of pain in the left hip and increasing limp. There was no history of injury and his general health was otherwise normal. (A) Anteroposterior radiographs of the pelvis at the time of diagnosis with the hip classified as Herring C and Catterall group IV; there was significant loss of epiphyseal height and widening of the medial joint space of the hip. (B) Anteroposterior radiographs immediately after shelf acetabuloplasty. (C) Anteroposterior radiograph showing that a significant increase in coverage of femoral head and CE angle. (D) Anteroposterior radiographs at 10-year follow-up indicating the remodeling of the femoral head with the hip classified as Stulberg 4.