Radiographic Assessment of Indications to Total Hip Replacement

Abstract

To our knowledge, five sets of criteria for total hip replacement have been proposed [1– 5]. The National Institute of Health has suggested that total hip replacement be considered in patients with radiographic evidence of joint damage, persistent pain and disability interfering with daily activities, and should not be recommended for patients at high risk of infection or those in poor general health [5]. This provides a very general statement rather than a set of criteria; this statement is not referring at all to any radiological aspect of the disease. Hawker et al. [2] defined potential candidates for total hip replacement as patients with a summed Western Ontario MacMaster University (WOMAC) OA Index score ≥39, clinical and radiographic evidence of arthritis, and no absolute contra-indication to total hip replacement. The estimate of potential need was then adjusted for willingness. The advantage of this set of criteria is that it is data-driven. The cut-off WOMAC score of 39 represents the 25th percentile of scores for patients undergoing hip or knee arthroplasty in Ontario. With regard to the potential utilisation of total hip replacement as an outcome measure, the drawbacks of these criteria are that they do not take into account either the structural severity of the disease or variability in antecedent pharmacological and non-pharmacological therapy, and also that they are sensitive to fluctuations in disease activity over time, co-morbidity and the patient’s willingness to undergo total hip replacement. They do not indicate which patients need total hip replacement, but in which patients total hip replacement is performed in Ontario, Canada.