Early post-traumatic avascular necrosis with secondary osteoarthritis following an acetabular fracture in a 19-year-old patient treated with total hip arthroplasty: a case report

Introduction and importance: Acetabular fractures are complex orthopedic injuries that can lead to severe long-term complications, including avascular necrosis (AVN) of the femoral head and secondary osteoarthritis. These sequelae may result in progressive joint destruction and may ultimately require total hip arthroplasty (THA), particularly in cases where joint preservation is no longer feasible. Case presentation: We report a case of a 19-year-old male presenting with progressive left hip pain and a restricted range of motion 1 year after sustaining a posterior column acetabular fracture associated with posterior hip dislocation. The initial injury had been treated with open reduction and internal fixation through a Kocher–Langenbeck approach. Radiographic and computed tomography imaging revealed the collapse of the femoral head with degenerative joint changes consistent with AVN and secondary osteoarthritis. The patient underwent cementless ceramic-on-ceramic THA using a direct lateral (Hardinge) approach. The postoperative course was uneventful. At the 90-day follow-up, the patient demonstrated complete pain relief, restoration of hip mobility, and the ability to resume normal daily activities without complications. Clinical discussion: Post-traumatic AVN remains a recognized complication after acetabular fractures, particularly when associated with hip dislocation. Even after adequate fracture reduction and fixation, disruption of femoral head vascularity may lead to progressive joint degeneration, requiring conversion to THA. Conclusion: This case highlights the potential for the early development of AVN following acetabular fractures. Careful long-term follow-up is essential, and THA remains an effective treatment for advanced post-traumatic hip degeneration, especially in young patients when modern ceramic bearing surfaces are used.