Sonography and intracapsular pressure in perthes' disease: 39 children examined 2-36 months after onset

Abstract

39 children with Legg-Calve-Perthes Disease (LCPD) and with a radiographically unsatisfactory development were examined with sonography regarding synovitis and with intracapsular pressure recording and aspiration performed 15 (2-36) months after the onset of symptoms. The mean anterior sonographic capsular distension was 3.0 (1.0-7.0) mm greater than that of the contralateral, asymptomatic hip. The mean intracapsular pressure was 4.5 (0-11.5) kPa with the hips in extension and neutral rotation, 9.7 (1.3-27.3) kPa with the hips in extension and inward rotation and 0.9 (-0.8-4.7) kPa in 45° of flexion. We conclude that these children have synovitis as diagnosed sonographically. This synovitis is probably symptomatically and prognostically important in LCPD due to increased intracapsular pressure, with pain, a decreased range of motion and, potential joint contracture.