Staged treatment of osteonecrosis of the femoral head induced by delayed treatment of polytrauma complicated by chronic acetabular fracture and hip dislocation: a case report.

Delayed intervention for hip fracture and dislocation is a core risk factor for osteonecrosis of the femoral head (ONFH). According to the latest research, the incidence of ONFH in patients with acetabular fracture combined with hip dislocation can reach 30%-40%, and this risk increases 1.89 times if treatment is delayed for more than 3 weeks. This presents a clinical challenge in polytrauma management, where systemic stability must be balanced against timely hip injury intervention under the principles of damage control orthopedics. This study reports the case of a 45-year-old man with severe polytrauma following a traffic accident. He suffered from extensive soft tissue injuries, bilateral pelvic and right acetabular comminuted fractures, central right hip dislocation, and multiple open injuries that required priority treatment. Repair of the right comminuted acetabular fracture with central hip dislocation was delayed for 53 days, ultimately resulting in secondary ONFH and requiring total hip arthroplasty (THA). Imaging examinations confirmed an Orthopaedic Trauma Association (OTA) acetabular fracture type 62-C, with a 2.5-cm displacement of the femoral head into the pelvic cavity. Staged interventions-including damage control, wound repair, hip reconstruction, and THA-were performed. At the 30-month follow-up, the patient demonstrated significant improvement in hip function [Harris Hip Score increased from 45 to 88 points, visual analog scale pain score reduced to 1 point]. This study systematically discusses the staged treatment strategies for polytrauma, surgical techniques for chronic hip fractures, and key considerations for the prevention and treatment of post-traumatic ONFH, thereby providing a practical clinical management framework for the staged treatment of similar complex polytrauma cases complicated by chronic hip injuries.