Hydroxyapatite-Coated Acetabular Cups in Primary Total Hip Arthroplasty: A Meta-Analysis

Cementless fixation is the predominant method used in primary total hip arthroplasties (THAs) performed in the United States, with porous and hydroxyapatite (HA)-coated implants used most commonly. Preclinical studies have demonstrated that HA-coated implants achieve superior fixation and stability compared to those with porous surfaces alone, yet the adoption of HA coating in clinical practice has been inconsistent. There have been few previous meta-analyses comparing HA-coated versus non-HA-coated acetabular cups. We hypothesized that HA-coated acetabular cups would result in a reduced incidence of revisions compared to non-HA-coated cups, with no difference in osteolysis, radiolucent lines, or patient-reported outcomes.

Medline, Embase, and Cochrane libraries were searched through November 2024 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The studies included were randomized controlled trials comparing HA-coated acetabular cups to non-HA-coated cups in primary THA. Outcomes included Harris Hip Score (HHS), endosteal bone formation, radiolucent lines, linear wear rate, revision for aseptic loosening, and heterotopic ossification.

There were significantly fewer radiolucent lines (P < 0.00001) for patients who had HA-coated cups. There was no significant difference in HHS (P = 0.20), endosteal bone formation (P = 0.23), linear wear rate (P = 0.44), acetabular component revisions for aseptic loosening (P = 0.29), or heterotopic ossification (P = 0.71) between HA-coated and non-HA-coated cups.

The results of our meta-analysis demonstrated that HA-coated acetabular cups in primary THA led to significantly fewer radiolucent lines than non-HA-coated cups. They did not show any advantage of HA-coated cups over non-HA-coated cups in terms of HHS, endosteal bone formation, linear wear rate, acetabular component revisions, or heterotopic ossification. These results suggest that HA-coated acetabular cups should be preferred over non-HA-coated acetabular cups in primary THA.