Legg-Calvet-Perthes disease and aseptic necrosis of the femoral head:MRI-semiotics of the terminal disease stage with outcome in deforming arthrosis

Introduction The changes that occur in the femoral head in Legg-Calvet-Perthes disease and aseptic necrosis in the early stages have been described sufficiently. The aim of the work was to study the condition of the hip joint in patients with Legg-Calve-Perthes disease and aseptic necrosis of the femoral head with magnetic resonance imaging (MRI) in the terminal stages of the disease and by formation of a symptomatic complex of deforming arthrosis. Materials and methods A retrospective single-centre MRI study (case series) included 15 patients with aseptic necrosis of the femoral head and Legg-Calve-Perthes disease. Results Among the studied group of patients, patients with stages III-IV of the disease prevailed. Five patients in the third - fourth stage of the disease had complete horizontalization of the cartilaginous labrum as a result of the outward displacement of the head. In seven patients, horizontalization was less pronounced, and the angle of the cartilaginous labrum ranged from 5 to 10°. The study of the cartilaginous acetabular index showed that in 9 out of 13 patients its value was less than 75-77 %. In stages III-IV, changes in the shape of the head and its lateralization is more pronounced. Discussion The complex of pathological changes in the hip joint in Legg-Calvet-Perthes disease and aseptic necrosis of the femoral head, especially in children, is most fully revealed with MRI, allowing to assess the state of the femoral head, acetabulum, all soft tissue and cartilaginous formations of the joint. One of the most important indicators is the lateralization of the cartilaginous labrum which reflects the severity of the mechanical stress in it resulting in displacement of the femoral head.