Clinical Results of Genesis-I Total Knee Arthroplasty for Patientswith Knee Osteoarthritis: A Five-year Longitudinal Study

Ten patients (17 knees) with knee osteoarthritis (OA) treated with the Genesis-I Total Knee Arthroplasty (TKA) System were clinically and radiographically evaluated after more than five years. The average Japanese Orthopaedic Association Knee Rating Score (JOA score) was 37 points (range, 25 to 40) before surgery, increasing to 84 points (range, 75 to 90) at the most recent observation. In the JOA score parameters (pain at walking, pain at stairs, range of motion, swelling), pain at walking was most improved. Range of motion (ROM) increased 8.4±19.3 degrees postoperatively, but the flexion angle decreased from 105.4±20 degrees to 99.4±15.0 degrees. No complications were seen in this study. Radiographic evaluation showed no evidence of loosening. The femoral component angle at the follow-up observation was 96.9±2.7 degrees in the anteroposterior (AP) view and 5.1±2.8 degrees in the lateral view. Tibial component angle was 88.8±2.4 degrees in the AP view and 85.8±3.5 degrees in the lateral view. Three of six knees with less than 3 degrees of posterior slope of tibial component had decreased knee flexion after TKA. In the patellofemoral joint, the non-resurfaced patella tilted laterally, but showed no subluxation, dislocation, or articular deformity. From this study, we believe that Genesis-I TKA is a successful surgical treatment for a patient with OA knee, and that the patella can remain unresurfaced.