Case Report: Combined posterolateral and direct anterior approaches for total hip arthroplasty in osteonecrosis of the femoral head with a rare massive osteophyte with literature review.

BACKGROUND: This report describes the surgical strategy and early clinical outcomes of a combined posterolateral approach (PLA) and direct anterior approach (DAA) for the management of osteonecrosis of the femoral head (ONFH) associated with a rare, massive encapsulating osteophyte. CASE PRESENTATION: We present the case of a 51-year-old male with bilateral ONFH and a 10-cm massive heterotopic osteophyte of the right hip. The lesion induced a severe mechanical incarceration effect, rendering safe surgical exposure via a single conventional approach exceedingly challenging. A dual-incision strategy combining PLA and DAA was therefore implemented, which allowed for safe osteophyte resection under direct visualization, in situ femoral neck osteotomy, and precise prosthetic implantation. OUTCOME: The procedure was completed uneventfully, with effective preservation of the femoral nerve anteriorly and the sciatic nerve posteriorly. At the 3-month postoperative follow-up, the patient's right hip pain had resolved completely, joint range of motion (ROM) was markedly improved, and the Harris hip score (HHS) increased from 50 to 98. Objective functional tests demonstrated a full return of normal gait and a significant improvement in the Timed Up and Go (TUG) test from 18 s preoperatively to 8.5 s postoperatively. CONCLUSION: For complex total hip arthroplasty (THA) involving severe anatomical distortion, a dual-incision strategy combining PLA and DAA enables safe surgery under 360°direct visualization. This approach serves as an effective salvage technique that reduces the risk of neurovascular injury.