Ceramic liner fracture after cementless alumina-on-alumina total hip arthroplasty.

Advances in technology have reduced the risk of fracture of ceramic total hip arthroplasty implants, but concerns remain about fracture of both components. We retrospectively reviewed 133 patients (157 hips) who had cementless alumina-on-alumina total hip arthroplasties with a sandwich-type acetabular component. Six patients (seven hips) died and five patients (six hips) were interviewed by telephone (95% followup). The 122 patients (144 hips) examined had a minimum followup of 36 months (average, 45 months; range, 36-68 months). All acetabular cups and femoral stems were radiographically stable at the last followup. Five hips in five patients (3.5%) were revised because of ceramic liner fractures. Ceramic liner fractures occurred at a mean of 35 months (range, 24-48 months) postoperatively. Acetabular cups in the fracture group (n = 5) were more anteverted than those in the nonfracture group (n = 139). In three patients the fracture apparently occurred during squatting, resulting in hyperflexion and wide hip abduction. Early ceramic liner fracture was associated with impingement associated with excessive anteversion of the acetabular cup in Korean patients who habitually squat.