Excellent Results of Isolated MPFL Reconstruction in Patients with and without High Grade Trochlea Dysplasia - Abstract
Introduction: Medial patellofemoral ligament (MPFL) reconstruction has become a well-established surgical technique to treat recurrent patellar dislocation. However, no golden
standard exists so far to treat a patellofemoral instability. An additive tracheoplasty is recommended for patients with a high-grade trochlear dysplasia, that means a lateral
trochlear inclination (LTI) of less than 11°.The following study was to ascertain if an isolated MPFL reconstruction results in comparable results in patients with and without trochlea dysplasia.
Methods: The study included 43 patients who underwent an MPFL reconstruction with a median age of 25.6 years and a median follow-up of 37.1 months. Patients were assessed by the International Knee Documentation Committee (IKDC), Tegner Activity, Lysholm and the visual analog scale (VAS) scores. On magnetic resonance imaging (MRI) LTI, Caton-Deschamps Index, tibial tuberosity to trochlear groove (TT-TG) distance and tibial tubercle-posterior cruciate ligament (TT-PCL) distance were measured. According to the LTI patients were divided into groups, group 1 with an LTI less than 11° and group 2 above 10°.
Results: The mean LTI of group 1 was 6,1 and 14,4 in group 2. The mean IKDC subjective score was 82 in group 1 and 81.6 in group 2. The mean Lysholm score was 84 in group 1 and 86 in group 2. Comparing the level of activity before and after the operation with the Tegner score showed that it was the same or even higher in 89% of all patients in group 1 and 92% in group 2. The mean VAS score was 2 (range 0-7) in group 1 and 1.6 (range 0-5) in group 2.77.8 % in group 1 were satisfied or very satisfied, whereas 92% in group 2 were satisfied or very satisfied. One patient in group 1 had a recurrent dislocation and one patient in group 2 had a subluxation postoperatively.
Conclusion: Patients with patellofemoral instability and a trochlea dysplasia achieved excellent results after an isolated MPFL reconstruction comparable to those without trochlea dysplasia. Thus, it seems that the MPFL can partially compensate the dysplasia. Therefore, the indication for a tracheoplasty should not just be according to radiological
measures.