The effect of the previous arthroscopic proximal realignment performed in the skeletally immature on the result of the anteromedial tibial tuberosity transfer

Abstract

Purpose: This study aims to evaluate the effect of the previous arthroscopic proximal realignment performed in the skeletally immature on the result of the anteromedial tibial tuberosity transfer(AMTT) by comparison the result of the staged operation which performed the AMTT at skeletally mature after arthroscopic proximal realignment at skeletally immature with the result of the delayed operation which performed the AMTT after the conservative treatment in the patients with recurrent patella dislocation had developed at skeletally immature.Method: We retrospectively reviewed the recorded of 412 patients (436 knees) who had diagnosed with recurrent patella dislocation from March 2001 to April 2009. Patients were categorized into two groups which had the AMTT at the skeletally mature after the previous arthroscopic medial plication and lateral release in the skeletally immature (Group S: 26 knees) and after the conservative management (Group D: 18 knees) to recurrent patella dislocation in the skeletally immature. Functional scores were assessed using the Lysholm score, the Kujala score and Tenger score. Clinical outcomes were determined from the data obtained before surgery and at the last follow-up visit.Result: There were no significant difference between the groups with regard to the demographic evaluation except the average number of dislocations before the AMTT (P<0.01) and the average span from dislocation after the primary management to the AMTT (P<0.01). There was improvement to radiologic indicator (average congruence angle, average of lateral patellofemoral angle, Insall-Salvati ratio, Tibial tuberosity-trochlear groove distance) between the preoperative and the last follow-up in both the groups. There was no significant difference between two groups regarding to radiologic indicator. Substantial improvement in Lysholm, Kujala scores, and Tenger score between the preoperative and the last follow-up were observed in both the groups. There were significant differences in Lysholm score (Group D 80.3 ± 6.0, Group S 85.5 ± 6.5), Kujala score(Group D 86.6 ± 3.9, Group S 86.6 ± 3.9), and Tenger score (Group D 5.7 ± 1.5, Group S 6.7 ± 1.4) between the groups at last follow-up (Lysholm score: P=0.012, Kujala score: P< 0.01, Tenger score: P=0.032).Conclusion: The AMTT after the previous arthroscopic proximal realignment performed in the skeletally immature had better satisfactory clinical results than the AMTT after the conservative management to the recurrent patella dislocation developed at skeletally immature. Sequence of arthroscopic proximal realignment in skeletally immature and the AMTT after closing the physis of the knee might be good option to manage to recurrent patella dislocation in skeletally immature.