Analysis of Containment of Femoral Head by Arthrographic findings in Legg-Calve-Perthes Disease

Ihn, Joo Chul; Kim, Ik Dong; Kim, Poong Taek; Park, Byung Chul; Park, Byung Jun

Abstract

The subluxation of the femoral head is one of important prognostic factors in LCPD and current treatment of LCPD is based on the premise that adequate containment of the vulnerable femoral head within the acetabulum during the process of repair should result in a more spherical femoral head and a more congruous joint than if treatments were not provided.We analised the arthrographic findings of 18 hips in unilateral LCPD in order to determine the changes of the femoral head and acetabulum, degree of the subluxation and containment of the femoral head in various position of hip. The results were as follows: 1. According to the result of sphericity, the femoral head was deformed mainly in coronal plane in LCPD. 2. Average medial joint space of normal hip was about 3.8mm in the AP view of hip, but it was more increased in any position of LCPD. 3. In abduction with internal rotation, average subluxation ratio was 7.5% in normal hip and 10.9% in LCPD. In abduction with external rotation, it was 8.3% in normal hip and 12.4% in LCPD. 4. In normal hip, the containment ratio was more than 1.0 in any position of hip, but the containment ratio was 1.03 in abduction with internal rotation and 0.95 in abduction with external rotation of hip in LCPD. 5. On the basis of these results, efficacy of the Scottish Rite orthosis was doubtful in most hips of LCPD.