Objective To observe the curative effect of knee arthroscopic medial patellofemoral ligament (MPFL) reconstruction and open medial retinaculum plication on adolescents with recurrent patellar dislocation, and analyze the complications. Methods A total of 58 patients with recurrent patellar dislocation admitted to the hospital were enrolled as the research objects from September 2020 to January 2022 were retrospectively analyzed. According to different treatment methods, they were divided into retinaculum plication group (n=31, open medial retinaculum plication) and ligament reconstruction group (n=27, knee arthroscopic MPFL reconstruction). The results of patellar fear test and imaging examinations ［patellar mobility, lateral patellofemoral angle, congruence angle, patellar tilt angle］, scores of pain ［visual analogue scale (VAS)］, knee function ［Lysholm knee scoring scale (LKSS)］ and Kujala patellofemoral function ［Kujala performance scale (KPS)］, and complications in the two groups were analyzed and compared. Results After treatment, patellar mobility, lateral patellofemoral angle, congruence angle and patellar tilt angle were decreased in both groups, which were lower in ligament reconstruction group than retinaculum plication group (P＜0.05). At the last follow-up, there was no significant difference in positive rate of patellar fear test between ligament reconstruction group and retinaculum plication group (0.00% vs 9.68%, P＞0.05). At 3d after treatment, VAS scores in both groups were increased, which were lower in ligament reconstruction group than retinaculum plication group (P＜0.05). After treatment, Lysholm and Kujala scores were increased in both groups, which were higher in ligament reconstruction group than retinaculum plication group (P＜0.05). After treatment, incidence of complications in ligament reconstruction group was lower than that in retinaculum plication group (7.41% vs 29.03%,P＜0.05).Conclusion The curative effect of knee arthroscopic MPFL reconstruction is good on adolescents with recurrent patellar dislocation, which can promote the recovery of knee function, relieve postoperative pain and reduce the incidence of complications