The rotating-platform, posterior-stabilized knee was designed to decrease polyethylene wear and to address challenges associated with Low Contact Stress mobile-bearing knees. The purpose of the present prospective study was to investigate the long-term clinical and radiographic results and the survival rate for this implant.
From January 2000 to October 2001, 117 consecutive patients (138 knees) underwent rotating-platform posterior-stabilized total knee arthroplasty with cement. All patients were followed prospectively. At a mean of 10 ± 0.4 years (range, 9.5 to eleven years) of follow-up, twenty patients had died and eight had been lost to follow-up, leaving eighty-nine patients (106 knees) for analysis.
A good to excellent result according to the Knee Society pain score, which improved from an average of 44 to 94 points, was achieved in 96% (eighty-five) of the eighty-nine patients in the final cohort. The mean knee motion improved from 111° to 119°. The prevalence of postoperative pain was 14%. The prevalence of asymptomatic crepitation was 9.4%, and the prevalence of painful crepitation requiring scar excision was 3.8%. Radiographic analysis revealed no malalignment, aseptic loosening, or osteolysis. There were three revisions: one for the treatment of infection and two for the treatment of traumatic supracondylar fractures. Kaplan-Meier analysis revealed that the ten-year survival rate was 100% with revision due to mechanical failure as the end point, 97.7% with revision for any reason as the end point, and 95% with any reoperation as the end point.
The ten-year follow-up of the rotating-platform, posterior-stabilized total knee arthroplasty demonstrated excellent clinical results and survival rates with no failures due to osteolysis or loosening.
Level of Evidence:
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.