Reconstruction of the Medial Patellofemoral Ligament Using a Synthetic Graft With Arthroscopic Control of Patellofemoral Congruence

Purpose To compare the results of reconstruction of the medial patellofemoral ligament (MPFL) using a synthetic graft (Poly-Tape) between knee joints in which the patella was reduced to the strict center and those in which it was slightly lateral to the center of the trochlea to determine whether patellar position within this range affects the results. Methods Forty-six knee joints in 46 patients were examined retrospectively with a minimum follow-up of 2 years. The position of the patellar central ridge in the trochlea on arthroscopy immediately after reconstruction of the MPFL was measured. The joints were classified into group 1 (6 male and 12 female patients), in which the patella was reduced to the strict center of the trochlea, and group 2 (10 male and 18 female patients), in which the patella was reduced slightly lateral to the center. The mean age was 20.7 years in group 1 and 20.3 years in group 2. Knee joints were assessed using the Kujala score and the International Knee Documentation Committee (IKDC) subjective evaluation score. Results The mean Kujala and IKDC scores improved significantly in both groups after surgery (both P < .001). There was no significant difference between the groups for any assessment before surgery or in the Kujala score after surgery ( P = .075). However, the IKDC score after surgery was significantly better in group 2 (91.3 ± 9.1) than in group 1 (82.8 ± 13.1) ( P = .012). Conclusions When recurrent dislocation of the patella was treated with MPFL reconstruction using a synthetic graft, subjective evaluations were better in knee joints in which the patella was repositioned slightly lateral to the center of the trochlea than in those in which the patella was reduced to the strict center, although there was no significant difference in knee function between them. Level of Evidence Level III, retrospective comparative study.