Abstract
Purpose
The fourth generation ceramic, in which zirconia is incorporated into the alumina matrix, was developed to reduce the risk of ceramic fractures. The purpose of this study was to evaluate the survivorship, clinical and radiographic results, and bearing-related failures associated with total hip arthroplasty using zirconia-toughened alumina ceramic-on-ceramic bearings over a minimum follow-up of 5 years.
Materials and methods
We retrospectively analysed 135 patients (151 hips) who underwent cementless total hip arthroplasty using zirconia-toughened alumina ceramic-on-ceramic bearings. There were 58 men and 77 women with mean age of 55.9 years (range, 20 to 82 years) at index surgery. Acetabular and femoral components were cementless in all hips. A 36 mm head was used in 81 of 151 hips and a 32 mm head was used in 70 hips with smaller acetabular shells. The mean duration of follow-up was 6.1 years (range, 5 to 6.8 years).
Results
Kaplan-Meier survival analysis with an end point of revision for any reason was 100% at 6.8 years. All acetabular and femoral components showed bony ingrowth. No radiographic evidence of osteolysis was identified. No ceramic fracture occurred. There were 4 (2.6%) noisy hips (1 squeaking and 3 clickings), but no patient could reproduce the noise and required revision. Other complications included one iliopsoas tendonitis and one dislocation.
Conclusions
The minimum 5-year results of total hip arthroplasties performed using 32 mm or 36 mm zirconia-toughened alumina ceramic-on-ceramic bearings were encouraging with excellent survivorship. However, it was also found that the risk of noise development remains even for the newest generation of ceramics.
