[Bilateral avascular necrosis after resurfacing hip arthroplasty. A case report]

Resurfacing hip arthroplasty is an alternative to conventional arthroplasty and it is indicated in young and active patients. Good results and the prevention of complications stem from a meticulous surgical technique and proper patient selection. We present herein the case of a 43 year-old patient who, after undergoing bilateral hip replacement with resurfacing prostheses, sustained a non-simultaneous fracture of both femoral necks due to avascular necrosis. He was treated by placing a metaphyseal anchoring stem. Postoperative X-rays showed proper implant placement without femoral notching, with a discrete 7 degrees valgus alignment of the femoral component. Both passive and active mobility was painful. X-rays showed cervical fracture of the right femur. The femoral head was attached to the implant, with no metallosis nor loosening of the femoral or acetabular components, but the bone had a fragmented and friable appearance that histopathologically was defined as avascular necrosis. Femoral neck fracture is the main complication after resurfacing hip arthroplasty. The effect of other factors like bone necrosis due to cement is unknown.