Unicompartmental and total knee arthroplasty in the same patient

This prospective randomized study compared the clinical and radiographic outcomes of unicompartmental knee arthroplasty versus total knee arthroplasty. The group consisted of 34 patients (19 males and 15 females), who had a mean age of 73 years (range, 49 to 86 years), and who fit the criteria for bilateral unicompartmental knee arthroplasty. Each patient received a unicompartmental prosthesis in one knee and a total knee arthroplasty in the other during a single anesthetic session. At a mean follow-up of 5 years (range, 24 to 89 months), the Knee Society pain and function scores were similar for both groups. There were no radiographic failures. Survivorship of the unicompartmental group was 85% compared with 100% in the total knee group (p = 0.05). All of the prostheses that failed had an all-polyethylene tibial component. These results suggest that unicompartmental knee arthroplasty may not offer similar survivorship when compared with total knee arthroplasty.