Ten-Year Results with Hydroxyapatite-Coated Total Hip Femoral Components in Patients Less Than Fifty Years Old

Abstract

To The Editor: I read with great interest “Ten-Year Results with Hydroxyapatite-Coated Total Hip Femoral Components in Patients Less Than Fifty Years Old” (2003;85:885-9), by Capello et al. I would like to thank the authors for their resolve to publish, together with the good results for the femoral component, the bad results for the cup component. The manufacturer of the Omnifit prosthesis has been concerned that the results of the cup and stem components would be published together, as witnessed by the discussion between the representative of the manufacturer and the board of the Swedish National Hip Arthroplasty Registerl. For the patient, every revision of a total hip replacement is equally unfortunate, be it a revision of the stem or the cup component. Waiting for any kind of revision operation produces equally severe preoperative anguish and stress in the patient. From this perspective, I would like to ask the authors the following questions: First, I believe that the survival of only 53.8% of all cup components during ten years postoperatively is so exceptionally low for a modern total hip prosthesis that the figure should be mentioned in the abstract together with the name of the cup model. I would like to know why the authors abstained from publishing this figure in the abstract. Second, the authors did not publish the combined revision rates for both components of this prosthesis. Was it because the combined revision rates of this prosthesis (for any reason) probably exceeded 50% during the ten years of follow-up? Third, the authors presented nice survivorship “curves” (life tables) for the cup components. Visual assessment of these “curves” indicates that the failure rate of the cup components accelerates with time. In comparison, two recent publications on the twenty-five-year results of cemented monoblock polyethylene total hip … Corresponding author: William N. Capello, MD Department of Orthopaedic Surgery Indiana University School of Medicine Clinical Building, Suite 600 541 Clinical Drive Indianapolis, IN 46202-5111 wcapello{at}iupui.edu