A previously unknown variant of the calcaneofibular ligament.

The lateral ankle joint is composed of three ligaments: the anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL) and calcaneofibular ligament (CFL). The ATFL and CFL demonstrate morphological variation, especially regarding their shape and number of bands. During standard anatomical dissection, an unusual type of triple CFL was observed: the CFL was composed of two bands originating on the lateral malleolus, and the presence of a lateral talocalcaneal ligament (LTC) originating on the talus bone. The insertion point of each band was located on the calcaneal bone. An understanding of these anatomical patterns provides a clearer view of ankle joint biomechanics, and improved the planning and performance of surgical treatment.