Eleven Years of Experience With Metal-on-Metal Hybrid Hip Resurfacing: A Review of 1000 Conserve Plus

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Abstract

Hip resurfacing is currently the fastest growing hip procedure worldwide. We reviewed 1000 hips in 838 patients who received a Conserve Plus (Wright Medical Technology, Inc., Arlington, Tenn) resurfacing at a single institution. The mean age of the patients was 50.0 years with 74.7% male. The hips were resurfaced irrespective of femoral defect size or etiology. The mean follow-up was 5.6 years (range, 1.1-11.0 years). All clinical scores improved significantly (P < .05). There was no acetabular component loosening. Ten were converted to total hip arthroplasty for femoral neck fracture, 20 for femoral loosening, 2 for sepsis, and 1 for recurrent subluxations. The 5-year survivorship was 95.2% with no failures in hips implanted since 2002. Short-term failures can be prevented. First-generation surgical technique and a low body mass index were the most important risk factors for the procedure. Improvements in bone preparation significantly increased prosthetic survival in hips with risk factors for failure.

Section snippets

Materials and Methods

From November of 1996 to September 2006, 1000 hips (838 patients) were implanted by the senior author (HCA) with the Conserve Plus metal-on-metal hybrid hip resurfacing device. The series started with the very first hip ever implanted with this design. The indications for the procedure at the time were very wide. There were no exclusion criteria either for bone quality (cysts) or quantity (osteoporosis) as long as the procedure was technically feasible and a total of 354 hips were resurfaced

Results

The mean follow-up for the whole series of 1000 hips was 5.6 years (range, 1.1-11.0 years). At the time of writing, 36 hips (30 patients) had no postoperative follow-up, 2 of them being considered lost to follow-up.

The mean preoperative UCLA hip scores were 3.6 ± 1.2 (SD) for pain, 6.4 ± 1.4 for walking, 5.8 ± 1.6 for function, and 4.7 ± 1.5 for activity. At last follow-up, UCLA hip scores were 9.4 ± 0.9 for pain, 9.6 ± 0.9 for walking, 9.5 ± 1.2 for function, and 7.5 ± 1.6 for activity. All

Discussion

There were no conversions to THR consecutive to a loosening of the acetabular component in this series. This result is of great importance as it justifies the concept of resurfacing in young and active patients who are likely to undergo more than 1 procedure during their lifetime: the durability of well-fixed porous-coated acetabular components retained at revision surgery has been demonstrated [19] and the availability of unipolar femoral heads matching the socket dimensions potentially

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  • Cited by (0)

    Funding for this study was provided by St Vincent Medical Center, Los Angeles, and Wright Medical Technologies Inc.

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