Complex Primary Total Hip Arthroplasty

Complex primary total hip arthroplasty (THA) is defined as a primary hip replacement performed in patients with previous hip joint disease, which precludes several surgical challenges and carries a greater risk of complications. Takedown of a fused hip is a technically demanding procedure associated with higher complication and failure rates than routine THA. The decisions to perform fusion takedown are unremitting mechanical pain at the adjacent joints (lumbar spine, ipsilateral knee, and contralateral hip), arthrodesis malposition, and excessive leg length inequality. Another complex THA occurs in protrusio acetabuli, in which dislocation of the femoral head may be difficult and carry the risk of intraoperative femoral fracture; thus, a femoral neck in situ osteotomy is usually necessary to facilitate exposure of the acetabulum. Challenges of THA following failed osteosynthesis of the proximal femur includes the following: poor quality of bone with marked osteopenia, proximal femoral bone loss, distorted anatomy of the proximal femur, and potential presence of infection as a cause for failure of the original surgery. THA following acetabular fracture is often more difficult than a primary procedure. When an acetabulum with extensive bone loss is approached, trabecular metal or custom-made cups should be taken into account for reconstruction. Finally, high-riding hip dysplasia offers a complex scenario for primary reconstruction. In cases of high dislocation, extensive soft tissue contracture could make hip reduction difficult or even impossible and also increases the risk of nerve injuries, making a femoral shortening osteotomy necessary. Preoperative planning is essential in these challenging scenarios, and many technical issues must be taken into account intraoperatively to avoid complications and enhance long-term implant survivorship.