Osteolysis after unidirectional and multidirectional mobile-bearing total knee arthroplasty in young patients.

We questioned whether a difference exists between multidirectional and unidirectional mobile-bearing total knee arthroplasties in terms of clinical results and the prevalence of polyethylene wear and periprosthetic osteolysis. We studied 62 patients who underwent simultaneous bilateral total knee arthroplasties, with a unidirectional prosthesis implanted in 1 knee and a multidirectional one in the other. Of the patients, 9 were men and 53 were women, with a mean age of 57.6 years (35-60 years). The minimum follow-up was 11 years (mean, 11.8 years; range, 11-13 years). Preoperative and postoperative knee and functional scores were not different between the 2 groups. No knee in either group had detectable tibial polyethylene liner wear or osteolysis on radiographs or on computed tomography scans. Two (3%) knees in each group were revised.