Transpatellar Reconstruction of Medial Patellofemoral Ligament by Semitendinous Tendon Autograft

Purpose of the study - to evaluate surgical treatment outcomes of the patients with chronical patella instability who underwent double bundle transpatellar reconstruction of medial patella-femoral ligament (MPFL) by a semitendinous tendon autograft. Material and methods. 26 patients with minimal 12 months follow up were included into the study. In all cases semitendinous tendon autograft was inserted through a vertical tunnel in the patella, formed in a loop, and fixed in femoral tunnel by a biodegradable screw. Preoperative MRIs were used to evaluate trochlear dysplasia type by D. Dejour classification, tibial tubercle to trochlear groove distance (TT-TG) and Insall-Salvati ratio. Postoperative x-rays were used to measure femoral tunnel angle (FTA), postoperative MRIs - to measure diameter of patella tunnel (d_Pat), distance from tunnel to medial border of patella (MPM) and diameter of tunnel in medial femoral condyle (d_Fem). Functional outcomes were evaluated by Kujala Score, Lysholm and IKDC, also the authors assessed the level of sports activity prior to and after the surgery. Results. Age median of the patients at the moment of procedure was 22 years. MRI data prior to surgery reported that the majority of patients suffered from B type of trochlear dysplasia, median TT-TG distance was 14.6 mm, median Insall-Salvati ratio was 1.1 mm. Postoperative x-rays and MRIs demonstrated median FTA of 18 degrees, d_Pat median 5.4 mm, MPM median - 7.0 mm, d_Fem median - 8.2 mm, no implant migrations were observed. Subjective assessment scores demonstrated excellent outcomes: Kujala Score - 96, IKDC - 87.4, Lysholm - 91. No secondary dislocations during follow up were reported, 48% of patients returned to sports on the pre-surgery or higher level, 52% of patients returned to sports with decreased activity. Conclusion. Transpatellar reconstruction of MPFL by semitendinous tendon autograft proved to be the efficient treatment method of chronical patella instability.