High-flexion mobile-bearing knees: impact on patellofemoral outcomes in 159 patients

Ethnic cultural demands of the patient have encouraged surgeons to use high-flexion designs. It has been speculated that these high-flexion designs may produce higher incidence of patellofemoral complications over conventional designs. We wish to report 5- to 7-year follow-up of this design with special emphasis on patellofemoral outcomes. We performed a prospective study involving 159 patients who underwent computer-assisted simultaneous bilateral total knee arthroplasty (TKA) with high-flexion design. Patients were evaluated clinically using Knee Society score (KSS), Western Ontario and McMaster University Osteoarthritis (WOMAC) score, and Hospital for Special Surgery patella score with a minimum follow-up period of 5 years. At last follow-up, mean scores were KSS (88.7), WOMAC (48.5), and HSS (86.7). All the scores improved postoperatively. Average preoperative range of motion was 108 degrees, which improved to 132 degrees postoperatively. There was no evidence of loosening or spin out in our study. Our study shows that TKA done using high-flexion rotating platform design results in near normal patellofemoral tracking patterns with improvement in function. The level of evidence of the study is IV.