Rheumatoid arthritis and hydroxyapatite-coated hip prostheses: five-year results. International ABG Study Group.

Medium- and long-term results from cemented total hip arthroplasty (THA) in patients with rheumatoid arthritis (RA) show a higher incidence of infection and aseptic loosening when compared to other diagnoses. Early results using uncemented prostheses are variable. Hydroxyapatite (HA) coatings are thought to improve early osseointegration in uncemented THA. In a prospective, international, multicenter clinical study, 32 RA patients who received 33 uncemented HA-coated prostheses were followed up for a minimum of 5 years. Medium-term clinical results are excellent. No infection or aseptic loosening has been recorded. Excellent osseointegration was observed radiographically. Bone remodeling was consistent with mainly proximal to midstem stress transfer. We conclude that uncemented, proximally HA-coated prostheses are a promising alternative to cemented prostheses for RA patients.