Introduction: Results of total hip replacement (THR) for aseptic osteonecrosis are controversial and conflicting according to implant type and generation. The present study consisted in a retrospective assessment of implant survival in primary THR for aseptic osteonecrosis, using a cemented stem, standard polyethylene press-fit acetabular component, and metal-metal bearing. The study hypothesis was that THR results are equivalent between aseptic osteonecrosis and osteoarthritis of the hip.
Material and method: A single-center retrospective study included 54 patients with metal-on-metal THR for femoral head osteonecrosis. The main endpoint was revision surgery for all causes, whether implant related or procedure related; secondary endpoints were complications and progression in clinical scores.
Results: Mean follow-up was 13.9 ± 1.6 years (range 12.0-17.1 years). Eighteen of the 54 patients (33.3%) died. Implant survival at last follow-up was 93.8% (95% CI, 87.1-100). There were 12 complications (22.2%): 1 intraoperative, 5 (9.3%) immediate postoperative, and 6 (11.1%) long term. Clinical assessment found a significant 43.1 point improvement in mean Harris score (p = 8.4E-33) and a 5.6 point improvement in mean PMA score (p = 2.9E-22).
Conclusion: Survival in primary THR for aseptic osteonecrosis was good. Follow-up needs to be rigorous to screen for onset of complications. Primary THR is thus justified in Ficat-Arlet stage 3 and 4 aseptic osteonecrosis of the hip.
Level of evidence: IV.
Keywords: Osteoarthritis of the hip; Osteonecrosis of the hip; Risk factors; Survival; Total hip replacement.