Estudo anatômico e tomográfico do posicionamento dos túneis femoral e tibial na reconstrução do ligamento cruzado anterior do joelho por meio das técnicas transportal e transtibial

Abstract

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction surgery aims to reestablish joint stability and improve knee function. Knowledge about ACL insertion-sites and ACL anatomy is crucial while positioning femoral and tibial tunnels. An anatomical landmark that represents a central position of femoral and tibial footprints has been studied. OBJECTIVES: Describe tomographic coordinates that represent a central position of femoral and tibial ACL footprints. Indeed, compare two ACL reconstruction techniques and their ability in achieving this central point in both sides (femur and tibia). METHODS: Eight cadaveric knees were dissected, and the central point of ACL femoral and tibial footprints were marked and analyzed using three-dimensional computed tomography. Moreover, 23 patients who presented with a reconstructed ACL 14 patients with transportal technique and 9 patients with transtibial technique were evaluated by the same method. RESULTS: In the cadaveric study, the means (and standard deviation) of ACL femoral footprint dimensions were in the ventraldorsal axis and in the cranialcaudal axis 9.4 ± 0.8 and 15.6 ± 0.9 mm, respectively. In the tibial side, the means of ACL footprint dimensions were in the anteriorposterior and in the mediallateral axis 18.5% ± 1.9% and 15.5% ± 1.0% mm, respectively. In the tomographic analyses, the means of femoral central location coordinates in the ventraldorsal and in the cranialcaudal axes were 35.3% ± 4.5% and 30.0% ± 1.6%, respectively. The means of tibial central location coordinates were in the anterior posterior and in the mediallateral axes, respectively: 40.5% ± 5.3% and 50.2% ± 1.3%, respectively. Regarding evaluation of transportal and transtibial groups, the following femoral central tunnel location (as mean) were found: 30.9% ± 5.9% and 33.2% ± 4.6% in the cranial-caudal axis, and 30% ± 6.5% and 4.2% ± 6.4% in the ventral-dorsal axis. Values in the tibial side were, respectively: 38% ± 6.5% and 46.0% ± 6.8% in anterior-posterior axis; and 47.2% ± 2.5% and 46.9% ± 2.1% in the medial-lateral axis. CONCLUSION: In the anatomical study, coordinates that represent the central location of femoral and tibial ACL footprints were defined, moreover, in the clinical study, transportal group attained coordinates that better resembled that location.