Effect of EndoButton double-bundle reconstruction of medial patellofemoral ligament in the treatment of recurrent patellar dislocation

Objective To investigate the recovery of knee joint function in patients with recurrent patellar dislocation treated by reconstruction of medial patellofemoral ligament with EndoButton double bundles. Methods A retrospective analysis was performed for 26 patients with recurrent patellar islocation who were treated in The Second Hospital of Tangshan from February 2014 to July 2016, with a total of 26 knees, aged 14-29 years.All patients underwent medial patellofemoral ligament reconstruction with autologous semitendinosus muscle.Double tunnel technique was used in medial patella and single tunnel technique was used in femoral side.Twenty-four patients were followed up for 12 to 24 months.The recovery of knee joint function was evaluated by Kujala score, Lysholm score, patellar fitness angle and patellar tilt angle before and after treatment. Results None of the follow-up patients had dislocation again, and the fear test was negative.The preoperative Kujala score and Lysholm score were (59.67±5.28) and (61.75±5.45) respectively.The corresponding scores at the last follow-up were (87.21±4.21) and (90.13±2.47). There were significant differences between the two scores (t=-19.98, -23.24, all P <0.01). The patellar fit angle changed from (23.17±3.63)degrees before operation to (14.17±2.01)degrees after operation.There was significant difference between the two scores.(t=10.62, P<0.01); Patellar tilt angle changed from preoperative (18.33±3.92)degree to postoperative (2.45±1.10)degree, the difference was significant (t=19.10, <0.01). Conclusion EndoButton double-bundle reconstruction of medial patellofemoral ligament is effective in the treatment of patellar dislocation with satisfactory recovery of knee joint function. Key words: Recurrent patellar dislocation; Medial patellofemoral ligament; Reconstruction; Knee joint function