The femoral neck in Legg-Perthes' disease. Its relationship to epiphysial change and its importance in early prognosis.

Like most other orthopaedic surgeons, we have never been satisfied with any available criteria for prognosis of Legg-Perthcs’ disease. Although the symptomatology is fairly consistent, the radiological changes are sometimes difficult to interpret as to the stage of the disease and its probable outcome. Most reported studies are concerned primarily with the appearance of the femoral head. We, on the other hand, have been especially interested in the changes in shape of the femoral neck. Can these changes be explained in terms of the blood supply to the head and neck and its influence on bone growth and remodelling? We know that shortening and widening of the neck in Legg-Perthes’ disease are variable. Can this be related to the extent of necrosis of the head ? Furthermore, can the degree of shortening and widening in the early stages be used to predict the ultimate anatomical shape of the femoral head ? The following studies were undertaken to investigate these possibilities.