Optimal suture anchor direction in arthroscopic lateral ankle ligament repair

In this study, the distance between the insertion point of the suture anchors and posterior surface of the fibula during arthroscopic lateral ankle ligament repair was investigated on computed tomography (CT) images. The hypothesis of this study was that there is an optimal insertional direction of the suture anchor to avoid anchor-related complications. One hundred eleven ankles of 98 patients who had undergone three-dimensional CT scans for foot or ankle disorders without deformity of the fibula were assessed (59 males, 52 females; median age 25.5 years; age range 12-78 years). The shortest distance from the insertion point of the suture anchor to the deepest point of the fossa/top of the convex aspect of the fibula was measured on the axial plane, tilting from the longitudinal axis of the fibula at 90A degrees, 75A degrees, 60A degrees, and 45A degrees. The distance from the insertion point of the suture anchor to the posterior surface of the fibula was also measured in a direction parallel to the sagittal plane of the lateral surface of the talus on the axial plane, tilting from the longitudinal axis of the fibula at 90A degrees, 75A degrees, 60A degrees, and 45A degrees. The posterior fossa was observed in all cases on the 90A degrees and 75A degrees images. The distance from the insertion point to the posterior surface of the fibula in the parallel direction was 15.0 +/- 3.4 mm at 90A degrees, 17.5 +/- 3.2 mm at 75A degrees, 21.7 +/- 3.3 mm at 60A degrees, and 25.7 +/- 3.6 mm at 45A degrees. The posterior points in the parallel direction were located on the posterior fossa in 36.0% of cases at 90A degrees, in 12.6% at 75A degrees, and in 0.0% at 60A degrees and 45A degrees. The suture anchor should be directed from anterior to posterior at an angle of < 45A degrees to the longitudinal axis of the fibula, parallel to the lateral surface of the talus, to avoid passing through the fibula. Cohort study, Level III.