Abstract
We report a case of the trochanteric fracture of the femur with the subluxation caused by the proximal migration of a pin after the Ender's method in a female aged 78 years. The penetration of a pin occurred within one week after the operation. This pin grinded the antero-lateral part of the acetabulum, and the hip joint became subluxated. The friction between the femoral head with subluxation and destroyed acetabulum grinded the postero-medial portion of the femoral head. This case was treated by the acetabular plasty with bone graft and cartilage bone graft.