Comparison of knees after patellofemoral stabilisation with asymptomatic contralateral knees

Patellofemoral instability (PFI) can significantly hinder and limit knee function. A widely accepted treatment of PFI is the medial patellofemoral ligament reconstruction (MPFLR), with or without additional procedures. This study aimed to evaluate postoperative functional outcomes in patients undergoing MPFLR by comparing the operated knee to the contralateral, asymptomatic knee using validated patient-reported outcome measures (PROMs).

From a prospective database, 71 adult patients (18 years or older) treated for chronic unilateral PFI between 2012 and 2019 were enrolled in a retrospective cohort study. Patients undergoing MPFLR, either in isolation or with TTT, with an asymptomatic contralateral knee were included. Pre- and postoperative comparisons of Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale, and EQ-5D-3L were conducted. Statistical significance was set at p < 0.05.

Seventy-one patients were included; median follow-up was 3.8 years. Postoperatively, significant improvements were observed in all KOOS subscales (p < 0.001), EQ-5D-3L-TTO (Δ0.11, p = 0.002), and EQ-5D-VAS (Δ13, p < 0.000), alongside increased Tegner Activity Scale scores (Δ1, p = 0.002). Despite these gains, operated knees demonstrated persistent functional deficits compared to contralateral asymptomatic knees across all KOOS subscales (p < 0.001). EQ-5D-3L-TTO showed significant inter-limb differences; small nonsignificant differences were noticed in the EQ-5D-VAS and Tegner Activity Scale score.

MPFLR significantly improves knee function, pain, and quality of life, yet does not fully restore function to the level of the asymptomatic contralateral knee. Persistent deficits highlight the need for further refinement in surgical techniques to optimize long-term outcomes.

level III.