Early clinical results of hydroxyapatite-coated total hip arthroplasty

A retrospective clinical and radiographic review of 25 conventional cementless total hip replacements (THRs) and 25 cementless hydroxyapatite-coated THRs was performed to evaluate early postoperative results. The hydroxyapatite-coated group had a higher incidence of pain-free arthroplasties compared with the standard cementless group (72% v 44%, P = .045) at the 2-month postoperative evaluation. At the 6-month evaluation, 76% of hydroxyapatite-coated THRs were pain-free compared with 52% of conventional cementless THRs, although the statistical significance disappears (P greater than .05). No differences between groups existed in the 6-month Harris hip scores, average motion, use of external support, Trendelenberg gait, postoperative implant radiolucent lines. Adding a 50- to 75-mug hydroxyapatite coating to a proximal one-third porous femoral prosthesis and porous surface acetabular cup improved the early clinical results in cementless THR. Whether this improvement in pain scores reflects a more stable cementless prosthesis via increased rates and amount of osseus ingrowth or adjunctive bone hydroxyapatite chemical bonding remains unanswered. Long-term follow-up of femoral subsidence and THR revision is needed to indicate the durability and success of hydroxyapatite coating.