Attempt to classify patients with arthritis of the hip suitable for prosthetic replacement, and their femoral heads.

Using clinical, radiological, and morbid anatomical data about patients with arthritis of the hip and their femoral heads resected during total hip replacement, an attempt has been made first, to classify patients and femoral heads by a cluster analysis technique, and secondly and more realistically, to use existing clinical and radiological classification as a basis for seeking discriminating features in the data from the femoral head. Both types of analysis failed to give results, and led to a conclusion that arthritis of the hip is a spectrum of disease. This may not pose problems to the clinician, but it does to the investigator studying the pathogenesis of osteoarthrosis. This problem is briefly discussed.