Abstract
This report documents insidious subcapital fracture of the femur with alcaptonuria in a 56-year-old-man. He had undergone total hip arthroplasty (THA) in the right side at the age of 53 years, and tenorraphy after Achilles tendon rupture in the right side at 56 years. On his first visit to our hospital, black pigmentation in the auricle and eye ball, and black urine were noted. He revisited our hospital for granual aggravation of left hip pain. Radiographs of the left hip showed displaced subcapital fracture of the femur. During THA, the femoral head and acetabulum were blackish. Histological examination demonstrated brownish pigmentation in the whole femoral head with scattering pieces of the cartilage. In addition to sharing force, accumulation of homogentisic acid in the bone and cartilage in the proximal femur were thought to have caused the subcapital fracture in this case.
