Hydroxyapatite coating does not improve uncemented stem survival after total hip arthroplasty!

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Implant Technology

Background:

• Debate exists regarding the efficacy of hydroxyapatite (HA) coating on uncemented stems in total hip arthroplasty (THA).
• Assessing implant survival and revision rates is crucial for uncemented hip stem designs.
• Understanding the impact of surface coatings on long-term implant performance is essential.

Purpose of the Study:

• To investigate the influence of HA coating on the early and long-term survival of uncemented hip stems.
• To compare revision rates for aseptic loosening and infection between HA-coated and non-HA-coated uncemented stems.
• To evaluate the clinical relevance of HA coating across different uncemented stem brands.

Main Methods:

• Analysis of 116,069 total hip arthroplasty (THA) procedures from the Nordic Arthroplasty Register Association (NARA) database (1995-2011).
• Comparison of 22 uncemented stem brands, with and without HA coating, focusing on revision endpoints.
• Utilized Kaplan-Meier survival analysis and Cox proportional hazards models to determine hazard ratios (HRs) for revision risk.

Main Results:

• Unadjusted 10-year survival for any component revision was 92.1%.
• HA coating showed no statistically significant effect on the adjusted risk of stem revision due to aseptic loosening (HR 0.8; p=0.4).
• The adjusted risk of revision due to infection was similar for HA-coated and non-HA-coated stems (HR 0.9; p=0.6).

Conclusions:

• Uncemented HA-coated stems demonstrated similar outcomes to uncemented stems with porous or sand-blasted surfaces.
• The presence of HA coating had no clinically relevant impact on the outcome of well-functioning stem designs.
• The study suggests that HA coating may not add significant value to established uncemented hip stem designs.