Acetabular bone stock reconstruction with frozen femoral head allografts and the use of a cementless screw cup in total hip revision surgery. A 5 years' clinical, radiologic and scintigraphic follow-up

This prospective study reviews the behaviour of a cementless conical screw cup in total hip revision surgery with or without the use of bone grafts to reconstruct acetabular bone stock. Clinical and radiologic results are given. For proper radiographic interpretation a new classification system is suggested, based on histologic features, the principles of which are explained. The results of auto- or allografts for the treatment of the same pathological condition are compared. The difference between both grafts successively in bone incorporation, biochemical behaviour, morbidity and mortality rate is discussed. The difference between a cancellous and a cortical bone transplant in the mechanism of repair is discussed. This study also analyzes acetabular bone graft activity using serial technetium-99m bone scans. Some guidelines for rehabilitation programs can be deduced from these observations. Finally, a correlation between graft incorporation and the acetabular deficiency to be reconstructed can be postulated.