231. HARVESTING THE BONE-TENDON-BONE FREE TRANSPLANT BY A MINI-INCISION VERSUS A CLASSICAL INCISION: PROSPECTIVE COMPARISON OF 40 CASES

Abstract

Purpose of the study: Grafting the anterior cruciate ligament with a bone-tendon-bone free transplant injures the harvesting site, causing sensorial disorders by injuring the infrapatellar nerve in 70% of the cases. Mini-invasive techniques can limit these complications. The purpose of this work was to analyse the feasibility of a mini-invasive technique using a single incision.

Material and methods: A prospective comparative study was conducted in our unit to compare a group of “classical” harvesting via an anteromedial incision and a “mini-invasive” technique using a incision centred on the patella with the graft being harvested with a specially designed harvesting instrument. Each group was composed of 20 patients. The patients were reviewed six to eight months postoperatively. Clinical assessment (IKDC, Lillois score, analysis of sensorial impairment) was associated with the radiographic and ultrasound analysis. Radiographic laxity was assessed on the stress views at 15 kg. The ultrasound study analysed the patellar tendon and the peritendon. Significance for statistical tests was set at 0.05 with correlation coefficients (R) determined with a covariance matrix ½ Log([1 + R]/[1−R]).

Results: The grafts harvested by the classical method presented good characteristics in all cases whereas this was true for only 45% of the mini-invasive grafts. Anterior pain was noted in 22% of patients in the classical group and in 33 of the mini-invasive group. There was no correlation between anterior knee pain and knee walking or thickness of the peritendon. A correlation was found between knee walking and asymmetry of the patellar tendon thickness in the mini-invasive group. The subjective IKDC score was the same in the two groups and the IKDC objective score was not significantly different (94% (A or B) in the classic group and 81% (A or B) in the mini-invasive group.

Conclusion: This mini-invasive technique with a single incision respects the infrapatellar branches of the medial saphenous nerve in 95% of the cases. But the quality of the graft is less satisfactory than with the classical harvesting technique. A correlation was found between the form of the anterior tibial tubercle which could be used to better define the ideal indication for this technique which remains a difficult procedure.