Lateral retinacular release combined with MPFL reconstruction makes a meaningful role in the treatment of Recurrent Patellar Dislocation: by a digital tensiometer test

Abstract

Purpose: Medial patellofemoral ligament (MPFL) reconstruction combined with lateral retinacular release (LRR) has become a common treatment for recurrent patellar dislocation, but it has not been feasible to find a reliable and definitive figure to compare the change in soft tissue tension on both sides of the patella before and after LRR. The aim of this study was to verify the change in graft tension by means of a digital tensiometer. Methods: Fifty patients, aged 18-40 years, were included in this study, treated with MPFL reconstruction simplely and no other osteopathic surgery. After the graft had passed through the femoral tunnel, graft tension was measured by connecting a digital tensiometer, and the change in graft tension was analysed before and after LRR, together with pre- and post-operative knee function scores ( Lysholm score and kujala score) and radiographic angle (patellar congruence angle,PCA;PTA patellar tilt angle,PTA). RESULTS: All 50 patients (52 knees) underwent MPFL reconstruction combined with LRR, with statistically significant differences in graft tension from 35.61±4.25N to 24.00±4.23N before and after LRR as measured by a digital tensiometer, and Kujala score and Lysholm score from 51.40±14.39 to 92.23± 4.74 and from 48.17±9.52 to 91.88±5.07, respectively, and PCA and PTA from 16.51±5.97° to 2.34±3.37° and from 25.43±4.53° to 11.62±2.54°, respectively, with statistically significant differences.There were no significant post-operative complications, with the exception of three patients who experienced slight discomfort at the patellar end when the weather became colder.At a mean follow-up of 53 months, there were 7 (14%) complications and no postoperative redislocations were observed.94% of the patients were satisfied with the results of the operation. CONCLUSION: LRR is meaningful for patients with recurrent patellar dislocation and is effective in reducing tension on reconstruction grafts.