CUSTOM MADE JUMBO SOCKET FOR RECONSTRUCTION OF LARGE BONE DEFECT IN REVISION TOTAL HIP ARTHROPLASTY

Abstract

A seventy-one-years old, female, has been treated by hemodialysis from 1977 due to renal failure. In April 19, 1985, she had Charnley Low Friction Arthroplasty for right hip joint. She often felt mild pain on the joint from 2000. Radiograph showed central migration of the socket and huge cystic bone defect of the acetabulum surrounded by thin cortical bone like an egg-shell form. Tear drop (acetabular floor) was diminished due to massive bone destruction or severe osteolysis. CT showed that the diameter of the cavity was approximately 10 cm. In March 1, 2002, the socket was upside down and moving freely in the cavity. The patient could not weight-bear on right lower extremity but walk without two crutches. Hemiarthroplasty for her left hip joint (contra-lateral side) was done in June 26, 2006, due to femoral neck fracture. Because of continuous right hip joint pain and walking disturbance, she underwent revision surgery in May 20, 2008. At the surgery, the cavity was empty except for the socket and fibrous tissue. Impaction grafting by using morselized allograft including porous and solid hydroxyapatite granules (100 g and 40 g each) was done after the socket and the tissue were extracted. A custom made all polyethylene socket (73 × 68 mm in diameter) was fixed by polymethylmetacrylate bone cement. Postoperative course was uneventful. She can walk with one crutch and ride on/off a vehicles without help four months postoperatively.

It is often difficult to reconstruct acetabulum with large bone defect in revision total hip arthroplasty. Especially, almost of support rings with hook cannot be applied in the case that the tear drop is destructive or absorbed. Impaction bone grafting is commonly used for reconstruction of bone defect in revision surgery. However, the extremely thick graft for large bone defect is at risk of collapsing lead to implant migration. The socket used in the case was custom made jumbo type to reduce the thickness of impaction grafting. It seems to be one of resolution to use the custom made jumbo socket for the case with large defect of acetabulum in revision total hip Arthroplasty.