Surgical and Anatomic Parameters Influencing Femoropatellar Pain in Total Knee Arthroplasty

Background: Femoropatellar pain occurs in up to 27% of patients after total knee arthroplasty. This complication may at least be partly related to postoperative malalignment and anatomic variations. Patients and Methods: In this study, 44 patients (eight male, 36 female) with an unconstrained knee arthroplasty (Genesis) without retropatellar resurfacing were evaluated over a follow-up of 40 (7-71) months. The patients' mean age at surgery was 69.3 (24-86) years. The Turba score was used for evaluation of the outcome. This score had been especially designed for femoropatellar knee pain. The type of patella (Wiberb), the patella shift, the patella tilt (Laurin et al), the patella height, the congruence angle (Merchant et al), and the lateral angle between femur and tibia were evaluated by X-ray examination. Results: Pain was found to correlate significantly with the subjective part of the Turba score. This result has to be expected as pain itself is a subjective criterion. But pain is not always accompanied by poor results in the objective part of the score. Contrary to the literature, the result of this study could not confirm that the parameters patela shift, congruence angle, patella height, lateral patella tilt, lateral femorotibial angle, patella type, and range of motion significantly correlate with anterior knee pain. Conclusion: For none of the investigated anatomic and surgical parameter, a connection with anterior knee pain after knee arthroplasty could be confirmed.