The fourth generation Delta ceramic, in which zirconia is incorporated into the alumina matrix, was developed to provide improved fracture toughness and wear characteristics. The purpose of this study was to evaluate the minimum 5-year outcomes and bearing-specific complications in a single surgeon series of Delta ceramic-on-ceramic total hip arthroplasties (THAs). We retrospectively analysed 667 patients (749 hips) who underwent cementless THAs using Delta ceramic-on-ceramic bearings by a single surgeon. There were 315 men and 352 women with mean age of 55 years (range, 16 to 88 years) at the time of index surgery. Acetabular and femoral components were cementless in all hips. A 36 mm head was used in 472 hips and a 32 mm head was used in 227 hips. The mean duration of follow-up was 6.3 years (range, 5 to 8 years).

The mean Harris hip score improved from 47.6 points preoperatively to 91.1 points at the time of final follow-up. All but one acetabular components were well-fixed, and all but one femoral components were well-fixed. No radiographic evidence of osteolysis was identified at the time of final follow-up. There were 2 (0.27%) ceramic liner fractures and no ceramic head fracture. A total of 48 hips (6.4%) exhibited an audible noise (29 clickings and 19 squeakings), but no patient required revision. Kaplan-Meier survivorship with an end point of revision for any reason was 98.7% at 6.3 years.

Delta ceramic-on-ceramic THAs provide excellent clinical outcomes without osteolysis at the minimum 5-year follow-up. However, we also found 0.27% ceramic liner fractures and 6.4% audible noises associated with the use of Delta ceramic-on-ceramic bearings.