Abstract
Purpose: The ideal bearing surface for total hip arthroplasty is still an area of debate. Increasing numbers of total hip replacements are being done in the younger patient population. Ceramic-on-ceramic bearings have gained popularity due to their low wear rate; however, ceramic fractures with subsequent catastrophic failures have been reported and squeaking of ceramic hips is an emerging problem. This study reports on early results of ceramic-on-ceramic total hip replacements.
Method: This is a study analyzing prospectively collected data for 120 alumina-on-alumina total hip replacements with minimum follow up of 24 months. Average age at time of surgery was 49 years. The main outcome of the study was to identify complications related to the pros-theses. Standard outcome measures (SF-12, Harris Hip Score, and WOMAC) were also collected at clinic visits.
Results: All patients received either a Stryker Trident acetabular cup with Secure-fit Plus stem or Depuy Pinnacle cup with an AML stem. Average follow-up was five years (range: two – nine years). No revisions were performed for loosening or catastrophic failures. No wear, loosening, or osteolysis was seen on radiographs. The SF-12, WOMAC, and Harris Hip scores were not significantly different from other reported hip series. The most common complication has been the “squeaking” hip. To date we have had six squeaky hips in our centre, three of which have been revised. All the squeaking hips received the Trident acetabular cup (Stryker) which has a circumferential metal lip to protect the ceramic bearing. This metal flange can affect range of motion and predispose patients to earlier impingement (particularly if a minus 3 head is utilized). One patient with a Depuy hip complains of intermittent pain and radiographs show some fragmentation, but the hip has not been revised.
Conclusion: Ceramic-on-ceramic bearing surfaces in total hip arthroplasty may provide a more durable prosthesis with outcomes similar to standard THA, especially in young and active patients; however, caution should be used if considering the Stryker Trident shell due to the large number of “squeaky hips”.
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