A993. ASSOCIATION BETWEEN SQUEAKING AND IMPLANT DESIGN AND MATERIALS IN CERAMIC-CERAMIC TOTAL HIP ARTHROPLASTY

Abstract

While alumina ceramic-ceramic THA has been performed in the US for more than 12 years, the phenomenon of frequent, clinically reproducible squeaking is relatively new. The current study investigates the influence of implant design on the incidence of squeaking.

We reviewed implant information on 1275 consecutive revision THAs performed from 10/2002 through 10/2007 to identify any patients who had complained of squeaking or grinding. We also identified, 2778 consecutive primary ceramicceramic THA. Of these, we reviewed the clinical records of 1,039 patients (37%) to date. Any patient complaint of squeaking or grinding at the time of an office visit or by phone interview was recorded. Hips were divided into group 1: flush mounted ceramic liner; group 2a: recessed ceramic liner mated with a stem made of TiAlV and using a 12/14 neck taper; and group 2b: recessed ceramic liner mated with a stem made of a beta titanium alloy comprised of 12% molybdenum, 6% Zirconium, and 2% Iron and using a neck taper smaller than a 12/14 taper.

Of the revision THAs, 5 hips (0.4%) were in patients who had complained of squeaking or grinding. All 5 hips had a recessed, metal-backed ceramic liner and evidence of metallosis. In primary THAs, Group 2b had statistically significantly (p=0.04) more squeaking (7.6%) than group 2a (3.2%) which had statistically significantly (p=0.002) more squeaking than group 1 (0.6%).

Squeaking following ceramic-ceramic THA is associated with use of a recessed metal-backed ceramic liner in combination with a femoral component made of a betatitanium alloy and using a relatively small head-neck taper. Since all revised hips in our study had metallosis, it is possible that metal debris is adversely affecting the bearing and that the elevated metal rim combined with a small head neck taper and the beta-titanium alloy contribute to this problem. Use of bearings with a flush-mounted ceramic liner mated with femoral components made of TiAlV and using a 12/14 taper appears to be prudent.