Non-concentric Reduction Due to Entrapped Loose Bone Piece During a Single-stage Bilateral Total Hip Arthroplasty.

Total hip arthroplasty (THA) is the treatment of choice for Grade IV avascular necrosis of the femoral head. Dislocation following THA, although rare, is a known complication. Common causes of unsuccessful reduction include interposition of soft tissue, component loosening, malalignment, and inadequate muscle relaxation following anaesthesia. Here, we encountered a rare complication during a single-stage bilateral THA that resulted in a non-concentric reduction on the left side. The pathology was a loose bone piece, which possibly was an osteophyte that was broken.