Primary Hip Survival of Hydroxyapatite-Coated Versus Non-hydroxyapatite- Coated Total Hip Arthroplasty Implants in a Veteran Population

Background: Hydroxyapatite (HA) coatings were introduced to improve uncemented implant osteointegration and to prevent loosening and osteolysis. However, data regarding these implants have been inconsistent. We studied the effect of HA coating of femoral stems and acetabular cups on component revision after primary total hip arthroplasty (THA) in the veteran population. Methods: We identified patients who underwent uncemented primary THA at any Veterans Health Administration (VHA) hospital from 2000 to 2017 and who had implants that were available as either HA-coated or non-HA-coated models. The endpoint was removal of the component of interest for any reason. For each individual stem and shell, unadjusted and adjusted (for age and body mass index) Cox proportional hazards models were used to estimate hazard ratios for the risk of explantation between HA-coated and non-HA-coated implants of the same type. Results: A total of 262 HA-coated cups, 4580 non-HA-coated cups, 4767 HA-coated stems, and 9397 non-HA-coated stems were available for analysis. The mean follow-up time was 9.01 years (43,627 total implant-years) for cups and 7.13 years (101,004 total implant-years) for stems. One of the two shells reviewed had significantly lower survivorship and an elevated hazard ratio for explantation with HA coating. Among the five implant pairs of stems, and the other shell, implant survival and hazard ratios for explantation were not affected by HA coating. Conclusion: HA coating did not improve THA implant survival in our veteran population. Although HA coated versions of hip implants tend to be more costly than their noncoated counterparts, these results do not support their general use. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study investigated the effect of HA coating on component revision after total hip arthroplasty (THA) in the veteran population. The results showed that HA coating did not improve the survival of THA implants, suggesting that its general use is not supported.