Summary

MPFL reconstruction might be the simples answer.

Abstract

Introduction

Medial patellofemoral ligament (MPFL) reconstruction has become a popular surgery for the treatment of patellofemoral instability. Patients report satisfaction and lower dislocation rate, with good results at mid-term. In literature, there are no studies reporting the long-term outcomes after MPFL reconstruction.

Matherials: A retrospective study was designed including all patients submitted to MPFL reconstruction between 2008 and 2013. Demographic and clinical data were collected, namely age, gender, number of dislocations, and revision surgery. Pre-operative patellofemoral (PF) relations measurements were assessed through computed tomography scan. After a minimum of ten-year follow-up period, patients were evaluated by magnetic resonance image, in which the PF indexes, chondral injuries, and trochlear dysplasia (according to Dejour classification) were assessed. Functional evaluation was also performed according to Kujala and Tegner Lysholm score.

Results

Data from 23 patients was gathered. The median follow-up time was 12 and a half years. At the time of surgery, the mean age was 18 ± 5 years and most of the patients were female.
An increase in the distance from the anterior tubercle of the tibia to the trochlear groove (TT-GT) was identified after reconstruction (16.20 [IQR 13.75-18.3] VS 20 [IQR 18-21] mm). Analysis of the patellar tilt showed a significant improvement at 0º extension (24 IQR 15-29.5º VS 15 IQR 6-5-26.75º; p=0.025) as well as with contraction (32 IQR 26-41º VS 22.5 IQR 9.25-37.5º; p=0.081) after surgery. In cases where Ficat surgery was performed (40%), we found a significant reduction in post-operative tilt values. 2 patients had a new episode of dislocation, requiring revision surgery in one case, with additional osteotomy. More than half of the patients had type III and IV chondral lesions, mainly on the lateral facet of the rotula. A correlation was identified between higher patellar tilt values (p<0.05) in these cases. The median Kujala score was 89 IQR 81.25-96.75 and the median Lysholm score was 86 IQR 76.75-94.75.

Conclusion

According to our data, MPFL reconstruction appears to have good clinical long-term results. Furthermore, it seems that the desired restrain effect remains effective. However, this procedure seems insufficient to correct maltracking alignment. In addition, a significant reduction in patellar tilt was observed, which, in theory, can contribute positively to the prevention of chondropathy in the lateral facet of the patella Our re-dislocation rate was around 8%, which is slightly superior to what is reported in literature, considering that this can be related to the sample size.