Reconstruction of the medical patellofemoral ligament through a double-bundle and suspension fixation of the adductor muscle tendon combined with semi-patellar ligament displacement for treating recurrent patellar dislocation in adolescents with unclosed epiphysis: a retrospective study.

Background: Reconstruction of the medial patellofemoral ligament is the core of the treatment of recurrent patellar dislocation (RPD). For adolescents with unclosed epiphysis, the surgical method is the key to the postoperative efficacy. And our study aimed to evaluate the clinical efficacy and imaging results of double-bundle and suspension fixation of the adductor muscle tendon combined with semi-patellar ligament displacement in the treatment of RPD in adolescents with tuberosity-trochlear groove (TT-TG) distance > 15 mm and unclosed epiphysis.

Methods: A total of 27 patients (13 males, 14 females, 27 knees) with recurrent patellar dislocation were included according to the relevant criteria. The patients were treated with double-bundle suspension fixation of the quadriceps femoris tendon and adductor muscle tendon combined with semi-patellar ligament displacement. International Knee Documentation Committee (IKDC) score, Tegner score, Lysholm score and Kujala score were used to evaluate knee function before and after the operation. TT-TG, lateral patella displacement (LPD) and patellar tilt angle (PTA) were measured by CT scan to evaluate patellar stability.

Results: All 27 patients were followed up for 30-45 months (mean 36.44 ± 4.34 months). At the last follow-up, the IKDC score, Tegner score, Lysholm score and Kujala score of the 27 patients were 89.00 ± 2.76, 3.89 ± 0.64,92.56 ± 2.03 and 91.07 ± 2.37, respectively. Compared with preoperative, the differences were statistically significant (p < 0.001). At the last follow-up, the TT-TG distance, LPD and PTA of 27 patients were 11.25 ± 0.89, 6.25 ± 0.57 mm and 9.89 ± 0.95°, respectively; compared with preoperative, the differences were statistically significant (p < 0.001). No related complications occurred in 27 patients.

Conclusion: Reconstruction of the medical patellofemoral ligament through a double-bundle and suspension fixation of the adductor muscle tendon combined with semi-patellar ligament displacement for treating recurrent patella dislocation in adolescents with unclosed epiphysis reached a satisfactory mid-term efficacy, the long-term efficacy still needs to be further explored.