Milošev, J Bone Joint Surg Am 2012 - Comparison of Ten-Year Survivorship of Hip Prostheses with Use of Conventional Polyethylene, Metal-On-Metal, or Ceramic-On-Ceramic Bearings

Comparison of Ten-Year Survivorship of Hip Prostheses with Use of Conventional Polyethylene, Metal-On-Metal, or Ceramic-On-Ceramic Bearings

Milošev, Pišot, et al.·J Bone Joint Surg Am·2012·85 citations·Retrospective cohort

Background

To improve the long-term performance of hip prostheses, alternative bearings with metal-on-metal (MoM) and ceramic-on-ceramic (CoC) couples have been introduced. Although currently the results from the use of these bearings are in the midterm stage, there have been few comparative studies of these different bearings.

Methods

From 2000 to 2002, 487 total hip replacements were performed with use of a BICON-PLUS acetabular cup and an SL-PLUS femoral stem (Plus Orthopedics, Rotkreuz, Switzerland, now Smith & Nephew Orthopaedics).
The patients were divided into 3 groups according to the type of bearing that was used: an MoM group (69 prostheses), a metal-on-polyethylene (MoP) group (200 prostheses), and a CoC group (218 prostheses).
Patient demographic data and data with regard to revision operations were evaluated from the hospital computer database.
The mean follow-up period was 8.5 years (range, 6.9 to 10.5 years).
Patient activity was assessed with use of the University of California at Los Angeles activity scale.

Results

The mean patient age was 60 years at the time of the index arthroplasty in the MoM and CoC groups, and 71 years in the MoP group.
Based on a scale of 10, the mean postoperative activity level was 6 in the CoC group, 5 in the MoM group, and 4 in the MoP group.
Survival at 10 years with regard to revision for any reason was 0.984, 0.956, and 0.879 for the MoP, CoC, and MoM groups, respectively.
When revision for any reason was considered as the end point, survival of the MoM bearings was significantly worse than that of the MoP bearings (p = 0.005).
Survival at 10 years with regard to revision for aseptic loosening was 0.995, 0.990, and 0.894 for the MoP, CoC, and MoM groups, respectively.
When revision for aseptic loosening was considered as the end point, survival of the MoM group was significantly worse than that of either the MoP group (p = 0.001) or the CoC group (p = 0.003).

Conclusions

When comparing 2 groups of patients of similar mean age and mean activity level undergoing total hip arthroplasty with the use of alternative bearings, CoC bearings had better survival than did MoM bearings at the 10-year follow-up; the difference was significant when revision for aseptic loosening was defined as a failure. However, neither the CoC nor the MoM alternative bearings provided improved midterm results when compared with the results of the conventional MoP bearings. For older, less active patients, traditional metal-on-polyethylene bearings are the appropriate choice.

Level of evidence: Therapeutic Level III. Copyright remains with the authors and publisher.

Supplemental

Comparison of Ten-Year Survivorship of Hip Prostheses with Use of Conventional Polyethylene, Metal-On-Metal, or Ceramic-On-Ceramic Bearings.

Milošev, Pišot, et al.J Bone Joint Surg Am201285 citationsRetrospective cohort