Comparison of anterior-posterior-glide and rotating-platform low contact stress mobile-bearing total knee arthroplasties.

BACKGROUND: The anterior-posterior-glide Low Contact Stress mobile-bearing knee prosthesis was developed to approximate the natural kinematics of the knee more closely than the rotating-platform Low Contact Stress mobile-bearing knee prosthesis does. The purpose of the present study was to compare the results associated with these two prostheses in patients managed with simultaneous bilateral total knee replacement.

METHODS: One hundred and ninety patients received an anterior-posterior-glide Low Contact Stress mobile-bearing prosthesis in one knee and a rotating-platform Low Contact Stress mobile-bearing prosthesis in the contralateral knee. The mean age of the patients at the time of the index procedure was sixty-four years. Eleven patients were men, and 179 patients were women. The mean duration of follow-up was 6.4 years (range, five to seven years). The patients were followed clinically and radiographically with use of the knee-rating systems of the Knee Society and the Hospital for Special Surgery.

RESULTS: The mean postoperative Hospital for Special Surgery knee score was 89.4 points for the knees treated with the anterior-posterior-glide mobile-bearing prosthesis and 88.6 points for those treated with the rotating-platform mobile-bearing prosthesis. Three knees in each group had a poor result. Two knees in each group had persistent moderate pain. One knee with an anterior-posterior-glide prosthesis had permanent tibial and deep peroneal nerve palsies, and one knee with a rotating-platform prosthesis had a permanent deep peroneal nerve palsy. No knee had aseptic loosening, revision, measurable wear of the tibial or patellar polyethylene bearing, or osteolysis.

CONCLUSIONS: After a minimum duration of follow-up of five years, the results associated with the anterior-posterior-glide and rotating-platform Low Contact Stress mobile-bearing total knee replacements were favorable and comparable.