Stabilizing lateral ankle instability by suture tape – a cadaver study

BACKGROUND: Suture tape is a recent development to augment a Brostrom repair at least during the healing phase of the native tissues used for stabilization of the lateral ankle ligaments. The purpose of this study was to evaluate whether suture tape is an effective mechanical stabilizer against anterior talar drawer in a cadaver experiment when tested with a validated arthrometer. METHODS: Different stability conditions were created in 14 cadaveric foot and leg specimens. Following anterior talofibular ligament (ATFL) dissection, isolated suture tape ATFL reconstruction was compared to the unaltered specimens, to the condition with ATFL cut, to the ATFL plus calcaneofibular ligament (CFL) cut conditions, and to the ATFL, CFL, and posterior talofibular ligament transected specimens. Three-dimensional bone-to-bone movement between fibula and calcaneus were simultaneously recorded using bone pin markers. Anterior translation was analysed between 20 and 40 N anterior talar drawer load, applied by an ankle arthrometer. Test conditions were compared using non-parametric statistics. RESULTS: Dissection of ATFL increased anterior talar drawer in arthrometer and bone pin marker analyses (p = 0.003 and 0.004, respectively). When the CFL was additionally cut, no further increase of the anterior instability could statistically be documented (p = 0.810 and 0.626, respectively). Following suture tape reconstruction of the ATFL, stability was not different from the unaltered ankle (p = 0.173). CONCLUSIONS: Suture tape augmentation of the ATFL effectively protects the unstable anterolateral ankle in the sagittal plane. The CFL does not seem to stabilize against the anterior talar drawer load.