Patient-based outcomes after medial patellofemoral ligament reconstruction

The purpose of this study was to evaluate subjective outcomes after medial patellofemoral ligament (MPFL) reconstructions.

Fifty-four knees of 46 patients who received MPFL reconstruction for recurrent patellar dislocations were examined with a minimum follow-up of two years. To assess patient-based outcomes, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Kujala score were assessed.

The mean Kujala score was significantly improved from 64.6 ± 22.1 pre-operatively to 84.7 ± 11.8 post-operatively (P < 0.001). The mean KOOS was also significantly improved post-operatively in all five subscales. Further, the mean scores of 41 out of the 42 questions for the KOOS were significantly improved after surgery, except those of the question about "grinding and clicking". When the KOOS was assessed individually, the scores on one or more subscales out of the five were worsened post-operatively in eight patients, and seven of the eight patients had decreased post-operative pain subscale scores. Furthermore, those eight patients (worse group) were compared with patients without any worsened scores on any of the subscales (better group). The mean pre-operative pain and sports/recreation function subscale scores were significantly higher in the worse group whereas the mean post-operative pain and symptoms subscale scores were significantly lower in the worse group than in the better group.

Overall, satisfactory patient-based outcomes were obtained after MPFL reconstruction in most of the patients. However, patients who only have mild pain pre-operatively tend to have worse subjective outcomes, and a caution may be needed when performing MPFL reconstruction on these patients.