Effect of Patellar Resurfacing on Patellofemoral Crepitus in Posterior-Stabilized Total Knee Arthroplasty.

BACKGROUND

Patellofemoral crepitus (PC) is a complication of total knee arthroplasty (TKA). Although patellar resurfacing (PR) directly influences the kinematics of the patellofemoral joint, the influence of PR on PC is unclear. The purpose of this study was to investigate the influence of PR on the incidence of PC.

METHODS

This study included 84 knees from 69 patients who underwent TKA using the Vanguard Complete Total Knee System, with or without PR (n = 42 each). Clinical evaluation of the incidence of PC; Knee Society Score; and radiographic measurements of patellar tilt, patellar distance, patellar shift, Insall-Salvati ratio, patellar flexion, femorotibial angle; and rotation of the femoral component was performed. Parameters were evaluated preoperatively and at postoperative months 2, 6, 12, and 24. Logistic regression analysis was conducted to investigate the effect of PR on the risk of PC.

RESULTS

The incidence of PC was significantly higher in the non-PR group than the PR group (33.3% vs 4.8%). The knees of the PR group displayed a significantly increased patellar tilt, medially shifted patella, and decreased patella flexion angle compared with those of the non-PR group. There were no significant differences in the other radiographic parameters or Knee Society Score. The absence of PR was associated with a much higher risk of PC (odds ratio, 10.37; 95% confidence interval, 2.18-10.37).

CONCLUSION

PR may decrease the incidence of PC by increasing the patellar tilt and medial shift and positioning the patella more closely parallel to the femur. PR is recommended during TKA with this prosthesis.