Effect of trochlear morphology over clinical outcomes after medial patellofemoral ligament reconstruction in patients with recurrent patellar dislocation: A retrospective cohort study.

BACKGROUND

Medial patellofemoral ligament reconstruction (MPFLR) is the standard procedure for recurrent lateral patellar dislocation. While low-grade trochlear dysplasia (TD) can be managed conservatively, trochleoplasty is recommended for high-grade TD. However, its indications and efficacy remain debatable. This study evaluates the clinical outcomes of MPFLR without trochleoplasty in patients with TD.

METHODS

57 patients who underwent MPFLR with a minimum follow-up of two years were included. TD was classified as low-grade (Dejour Type A) or high-grade (Types B, C, D). Patient-reported outcome measures (PROMs)-Kujala, Lysholm, and International Knee Documentation Committee scores were assessed pre and postoperatively and correlated with TD grades. Pre- and postoperative PROMs were also correlated with age, gender, patella alta, patellar cartilage defect, preoperative PROMs, and type of surgery.

RESULTS

The mean age at surgery was 26.9 years, and 64.9 % were female. At a mean follow-up of 72 months, no patient experienced a recurrence of dislocation. Postoperative PROMs showed a significant improvement (p < 0.001). Patients with low-grade TD had significantly better PROMs compared to those with high-grade TD (p < 0.05). While increasing age, cartilage lesions, and trochlear dysplasia had a significant correlation with PROMs, regression analysis revealed that preoperative Kujala score and trochlear dysplasia were major determinants of PROMs. Furthermore, there was no effect of gender, patella alta, or type of surgery on PROMs.

CONCLUSION

Isolated MPFLR significantly improves PROMs and prevents recurrence, even in patients with high-grade TD. Among all variables, Trochlear dysplasia is the most influential determinant of PROMs.

LEVEL OF EVIDENCE: III, retrospective cohort study.