Fully Hydroxyapatite-Coated, Collared, Triple-Taper Stems May Be Safe for all Patients Undergoing Primary Total Hip Arthroplasty: Minimum Two-Year Follow-Up.

Abstract

The triple-tapered, collared, hydroxyapatite-coated stems for cementless total hip arthroplasty (THA) show a low rate of early failure and excellent performance. The purpose of this study was to evaluate the possibility of implanting these stems for any patient undergoing THA, regardless of age and bone quality. This was a retrospective study at a single institution using a prospectively collected data registry of 265 triple-tapered, collared, fully hydroxyapatite-coated stems implanted for primary cementless THA. We collected data on demographics and clinical outcomes, including the 12-item Short Form/Veterans RAND (SF/VR-12) health survey and Hip Dysfunction and Osteoarthritis Outcomes Score for Joint Replacement. Survivorship, revision etiology, and radiographic outcomes were also assessed. The minimum follow-up was two years. The average patient age was 68 years (range, 39 to 89), and their average body mass index was 29.9 (range, 17 to 45). The physical health SF/VR-12 score increased 0.4 points from a preoperative average of 34.8 (range, 18.4 to 56.6) to a postoperative average of 35.2 (range, 18.1 to 56.6, P = 0.516). The mental health SF/VR-12 improvement was 0.7 points from a preoperative average of 50.3 (range, 19.1 to 69.0) to a postoperative average of 51.1 (range, 26.9 to 68.6, P = 0.412). There was a significant improvement of 18.8 points in the Hip Dysfunction and Osteoarthritis Outcomes Score for Joint Replacement score from a preoperative average of 41.6 (range, 8.1 to 76.8) to a postoperative average of 60.4 (range, 8.1 to 100, P < 0.0001). The 2-year survivorship was 98.1%. There were five revisions: two for infection, two for dislocation, and one acetabular periprosthetic fracture. Another two patients had a femoral periprosthetic fracture without requiring femoral component revision. Radiographs demonstrated well-fixed implants in 100%. Fully HA-coated, triple-tapered cementless component THA offers excellent results at 2-year follow-up in an unselected patient population.