The dynamic reconstruction of the medial patellofemoral ligament shows good subjective outcomes but high rates of recurrent instability: a systematic review and meta-analysis.

Purpose: The surgical reconstruction of the medial patellofemoral ligament (MPFL) is a commonly used treatment for recurrent patellar dislocations. A surgical method which is frequently used is the dynamic reconstruction of the MPFL (dMPFLr), which involves attaching the released end of a hamstring muscle to the medial patella using a pulley. The aim of this systematic review and meta-analysis is to evaluate the evidence of this method in terms of patient-reported outcomes, the rate of recurrent instabilities, and other complications. Methods: MEDLINE® and Web of Science™ were used to identify eligible studies. We used a random-effects meta-analysis to estimate the pooled rates of the Kujala scores, rates of recurrent instabilities, and complication rates. Results: A total of 1,087 studies were screened for eligibility. Six studies, comprising a total of 267 treated knees, met the inclusion criteria and were included. All the publications included were retrospective analyses (level of evidence III). The random-effects model showed an overall mean postoperative Kujala score of 86.74 (95% CI: 79.37-94.11; heterogeneity: I 2 = 94%), a recurrent instability rate of 13% (95% CI: 9-18%; heterogeneity: I 2 = 0%), and additional complications mentioned at a rate of 9% (95% CI: 5-16%; heterogeneity: I 2 = 0%). Conclusion: Although good results are achieved with regard to the patient-reported outcomes and complication rates, there is a high rate of recurrent instabilities. Despite these results, dMPFLr can be considered an option for the treatment of skeletally immature patients, as it avoids the need for intraoperative fluoroscopy and the risk of epiphyseal joint injury due to femoral fixation.