Abstract
We assessed polyethylene wear and osteolysis in 15 patients (30 hips) undergoing staged bilateral total hip arthroplasty, who had a cemented hip arthroplasty on one side and a hybrid arthroplasty on the other. All factors apart from mode of acetabular component fixation were matched. Wear was measured radiographically using Livermore’s technique.
The mean clinical and radiological follow-up was 11.2 years for the cemented arthroplasties and 10.7 years for the hybrid arthroplasties. Mean annual linear wear rate for the cemented cups was 0.09mm/year, and 0.14mm/year for the uncemented cups. This difference was statistically significant (p=0.03), confirming previous reports that polyethylene wear in uncemented cups is greater than in cemented cups. Polyethylene wear in the uncemented cup exceeded wear in the cemented cup by more than > 0.1mm/year in 5 patients, 4 of whom had a BMI of greater than 30.
No periacetabular osteolysis was noted. Femoral osteolysis was present in 5 hybrid arthroplasties and 2 cemented arthroplasties. Zone 7 femoral osteolysis occurred in 3 patients on the side of the hybrid arthroplasty, multifocal femoral osteolysis not involving zone 7 was seen in 2 patients in both hips.
Correspondence should be addressed to Editorial Secretary Mr ML Costa or Assistant Editorial Secretary Mr B.J. Ollivere at BOA, 35–43 Lincoln’s Inn Fields, London WC2A 3PE, England; Email: mattcosta@hotmail.com or ben@ollivere.co.uk
