Patellofemoral complications following total knee arthroplasty. Correlation with implant design and patient risk factors.

Results of 211 total knee arthroplasty operations were retrospectively evaluated to identify patients with knees at greatest risk for the development of patellofemoral complications and to determine the incidence and type of patellofemoral complications associated with different patellar implants. Patellofemoral complications occurred in 27 knees (12.8%). Osteoarthritis and obesity were associated with an increased incidence of patellofemoral problems. Significantly higher rates of patellofemoral complications were noted with metal-backed patellar implants and with patellar components implanted without cement. The loosening rate with cementless fixation was 13.5%. The lowest rate of patellofemoral complications following total knee arthroplasty was obtained with all-polyethylene domed patellar components implanted with cement.