Changes in patellar tracking after total knee arthroplasty: 10-year follow-up of Miller-Galante I knees.

Changes in patellar tilt angle and patellar displacement were evaluated in 18 knees with the Miller-Galante I knee arthroplasty system (Zimmer, Warsaw, Ind). Mean follow-up was 10 years. Patellar tilt angle at final follow-up (5.7 degrees) was significantly larger than at 1 year postoperatively (2.8 degrees). Patellar displacement at final follow-up (5.1 mm) was significantly larger than at 1 year postoperatively (3.4 mm). Preoperatively, patellar tilt angle showed a statistically significant correlation with the change in tilting angle during follow-up. These results suggest patellar tracking can worsen during the long-term postoperative period.