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The fracture rate of third-generation ceramic liners is greatly reduced compared with first- and second-generation liners because of improvement in the design and manufacturing process. The ABC (alumina-bearing couple) ceramic liner is one such design, and fracture of this type of liner has not been reported. We report three cases of fracture of an ABC ceramic liner occurring within 3 years of implantation. The liner was broken into multiple pieces in two patients, whereas in one patient it was broken only in its periphery. These patients were treated with débridement and cementation of the metal-inlay polyethylene liner into the retained acetabular shell.

Implantation of a cementless press-fit acetabular cup during hip arthroplasty alters stress transfer to the periacetabular bone, resulting in stress shielding of cancellous bone and enhanced load transfer to cortical bone. Theoretically, the thicker, stiffer and larger acetabular cup of a hip resurfacing may increase periacetabular bone stress shielding. We attempted to assess the matter (at a minimum of 2 years after surgery) by measuring any difference in supra acetabular bone mineral density (BMD) between the side implanted with a thick monoblock cobalt-chromium (Co-Cr) acetabular component during hip resurfacing (HR) and the opposite non-operated side. We retrospectively recruited 44 patients who had undergone metal-on-metal hybrid hip resurfacing for unilateral osteoarthritis of the hip joint . BMD of the supra acetabular bone of both hips was measured using a dual energy X-ray absorptiometry (DEXA) scan. The BMD measured in Zone 2 was not different on the operated side (1.69 g/cm2 ± 0.48) compared with the non-operated side (1.70 g/cm2 ±0.49) (p=0.904). Contrary to our expectations, implantation of a monoblock Co-Cr acetabular component during HR did not cause significant stress-shielding of supra acetabular cancellous bone.