Ceramic Head Fracture in Ceramic-on-Polyethylene Total Hip Arthroplasty
A 72-year-old woman underwent THA for idiopathic osteonecrosis of left femoral head in February, 2000. In 2012, she visited our emergency room for left hip pain with clunk sounds after squatting position 3 days ago. She had no problems in gait before the accident of squatting position. She has obese appearance; her height was 164 cm, weight was 90 kg, and bone mass index was 33.5 kg/m2. There was no evidence of infection including redness or heating sensation around left hip.\nPlain radiographs showed ceramic head fractures with multiple fragments around the joint. The former arthroplasties included the cementless cup (Trilogy® acetabular system, Zimmer, Warsaw, IN, USA), cementless stem (Versys® hip system, Zimmer, Warsaw, IN, USA), polyethylene liner (Trilogy® acetabular system, UHMWPE, Zimmer, Warsaw, IN, USA), and ceramic head (Versys® hip system, 28 mm diameter, short neck length, zirconium oxide ceramic). The inclination of acetabular cup was 43 degree, and anteversion was 10 degree, which were within acceptable range ().\nRevision operation was done. Posterolateral approach was used, similar to previous operation. After capsulectomy thorough posterolateral approach, various sizes of ceramic particles were observed. Intraoperatively, ceramic fragments were meticulously removed, and extensive capsulectomy was performed. Inner surface of polyethylene liner and metal neck taper junction of the femoral components were severely scratched to retain (). There were concerns about refracture of ceramic head and galvanic corrosion of metal head because of the scratched femoral neck. Thus, femoral stem was removed. In addition, the acetabular cup that was loosened because of osteolysis was also removed. After the removal of all components, massive irrigation and extensive synovectomy were done to remove microscopic ceramic fragments.\nFor revision, new cementless acetabular cup (Delta-PF Cup, Lima, Udine, Italy), full-coated modular cementless stem (Revision hip uncemented stem-Lima, Udine, Italy) were used. And, the 4th generation ceramic liner (Neutral liner, 36 mm I.D., Biolox Delta, CeramTec, Plochingen, Germany) was implanted for revision surgery. Full-coated modular cementless stem (Revision hip uncemented stem-diameter 16 mm, length 140 mm, Neck with screw-height 60 mm, Lima, Udine, Italy) was inserted with allogenic bone graft around proximal femur. Finally, the 4th generation ceramic head (Femoral head, 36 mm short taper 12/14, Biolox Delta, CeramTec, Plochingen, Germany) was applied. Intraoperative testing of the stability of the revised implants was advisable. The cup position was checked with 42 degree of abduction, and 31 degree of anteversion in postoperative plain radiographs ().\nAt her 6 months follow-up, she could return to her previous level of activity, and had Harris hip score of 82. In radiographs, the implant showed stable fixation without sign of osteolysis or loosening.