Long-term hip survival and factors influencing patient-reported outcomes after transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head: A minimum 10-year follow-up case series

Objectives: This retrospective study aimed to assess long-term hip survival after transtrochanteric anterior rotational osteotomy (ARO) for osteonecrosis of the femoral head (ONFH) and identify factors influencing patient-reported outcome measures (PROMs) in patients with preserved joints. Methods: Altogether, 95 consecutive hips in 85 ONFH patients who underwent ARO during 2000–2007 (86.7% follow-up) were studied. Controls were 35 patients with 41 hips with ONFH managed conservatively for >1 year after collapse. We analyzed hip survival using the Kaplan–Meier method, with the endpoint defined as any therapeutic surgery related to ONFH. We also evaluated PROMs for both groups in patients with surviving hips and available radiographs at the final follow-up. Results: The 10-year hip survival rate after ARO was 85.4%, which was significantly higher than the 5-year rate in the control group (50.4%). Multiple regression analyses showed that the presence of osteoarthritic change after ARO was significantly associated with poor scores for both the Oxford Hip Score and the Short Form-12 Health Survey Physical Component Summary. Conclusions: ARO could effectively preserve hip joints with post-collapse ONFH, although the presence of osteoarthritic change could lead to lower satisfaction even among patients with long-term hip survival after ARO.