Background: The durability of uncalcined and unsintered hydroxyapatite-poly-l-lactide composite screws is unclear when used for the fixation of acetabular bone graft in total hip arthroplasty under full-weight conditions. We have used this type of screw for the fixation of acetabular bone graft in cemented or reverse-hybrid total hip arthroplasty since 2003. Hence, we conducted a follow-up study to assess the safety and efficacy of these screws when used for cemented socket fixation.
Methods: In this study, 98 patients (106 cases) who underwent fixation of acetabular bone graft in cemented or reverse-hybrid total hip arthroplasty using hydroxyapatite-poly-l-lactide composite screws were followed up for over 5 years and evaluated clinically and radiographically. The patient population comprised 10 men and 88 women with a mean age of 60.3 years (range, 41-81 years) at the time of surgery. The original diagnosis for primary total hip arthroplasty was secondary osteoarthritis in 97 cases and high hip dislocation in nine cases.
Results: The mean follow-up period was 7.6 years (range, 5-11 years). No patient in this series required revision surgery, and no radiographical loosening occurred during the follow-up period. The mean Japanese Orthopaedic Association score improved from 48 (range, 7-73) preoperatively to 87 (range, 50-100) at the final follow-up. Radiographically bone graft consolidation was confirmed in all cases, and no apparent osteolysis around the cemented socket or composite screws was detected. Kaplan-Meier survival analyses with socket revision surgery for any reason, socket loosening, and appearance of a radiolucent line >1 mm in any zone as the endpoints yielded survival rates of 100%, 100%, and 86.8% at 5 years, and 100%, 100%, and 81.0% at 10 years, respectively.
Conclusion: This absorbable screw seems to have no negative effects on the mid-term clinical results of cemented socket fixation.
Copyright © 2015 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.