Catastrophic ceramic failure in total hip arthroplasty: the role of microseparation

In May 2008, a left total hip arthroplasty was undertaken for the treatment of end-stage osteoarthritis in a 77-year-old man with a body mass index of 25 kg/m. A cementless total hip arthroplasty prosthesis was implanted through a transgluteal approach. A combination of a ceramic acetabular liner with a 36 mm ceramic femoral head was chosen. During the procedure, a low femoral neck cut resulted in a fracture of the greater trochanter, which was subsequently fixed with two partially threaded screws. Immediate postoperative radiographs revealed satisfactory orientation of the components and a fixed greater trochanter. The patient made an uneventful recovery and was discharged on the seventh postoperative day with instructions to walk with the use of crutches, partially weight-bearing for six weeks. At six weeks the previously fixed greater trochanter was found to be avulsed (Figure 1). The patient had no symptoms and was therefore allowed to mobilize fully weight-bearing. At the six-month follow-up the prosthesis was considered to be functioning well on the basis of satisfactory pain relief as reported by the patient. He was able to walk unaided, with a normal gait. The hip had an excellent range of movement with no tenderness over the greater trochanter and there was no limb length discrepancy. At 15 months postoperatively the patient reported the sudden onset of pain-free squeaking with no history of trauma. Radiographs revealed a fracture of the ceramic acetabular liner (Figure 2) and seven days later revision surgery was undertaken. The fractured liner and the partially threaded screws were removed and thorough debridement of multiple small fragments of ceramic was undertaken. The femoral head exhibited macroscopic signs of wear and was removed as well (Figure 3). Having checked the stability of both prosthetic components, revision consisted of the exchange of the acetabular liner and the femoral head with ceramic implants of the same size as the originals. During the procedure, the greater trochanter was found enveloped in fibrous tissue, partially comminuted. The abductors were found to be atrophic and were reattached with transosseous sutures to the proximal femur. The patient made an uncomplicated recovery and was discharged on the fifth postoperative day. At 24 months following the revision procedure (Figure 4), the patient was pain-free and able to mobilize unaided.