ORIGINAL ARTICLE Anatomical review of the lateral collateral ligaments of the ankle: a cadaveric study Omer A. Raheem • Moira O’Brien Received: 24 February 2011 / Accepted: 22 April 2011 / Published online: 15 May 2011 Ó Japanese Association of Anatomists 2011 Abstract Arrangements of the lateral collateral ligaments of the ankle are complex. Injuries to these ligaments can occur in the inverted planter flexed position of the ankle. Traditionally, the anterior talofibular ligament (ATFL) is the first ligament involved in such ankle injuries. We reviewed the anatomical arrangements of the lateral ankle. Twenty ankles from ten Caucasian cadavers were carefully dissected. Length and width of each ligament were mea- sured in neutral, dorsiflexion and plantar flexion. The angle between the ATFL and other ligaments was also recorded. ATFL was present in 95% of ankles dissected. Five ankles showed two slip configuration of the ATFL. One ATFL was noted as being significantly thicker and another one was significantly narrow. Mean length of the ATFL in neutral was 15.5 mm (range 10–21 mm), which increased in plantar flexion to 18 mm (range 11–25 mm) and decreased slightly in dorsiflexion to 14.5 mm (range 10–19 mm). The calcaneofibular ligament was present in all dissections and had a mean measurement of 18.5 mm in neutral (range 14–23 mm) decreasing to 17 mm in planter flexion and 15.5 mm in dorsiflexion. Treating ligamentous ankle injuries can be very costly, thus creating a large economic burden to both patients and health institutions. Understanding the anatomical characteristics of the lateral collateral ligament complex of the ankle provides the basic foundation for understanding injuries and helps to clini- cally manage such injuries appropriately. Keywords Anatomy Á Lateral collateral ligaments Á Ankle Introduction The ankle, or talocrural joint, is a uni-axial modified synovial hinge joint with its articular surfaces covered with hyaline cartilage. The ankle joint is surrounded by a fibrous capsule, which is attached just beyond the articular margins except anteriorly and inferiorly, where it attached to the neck of the talus. The capsule is a thin, weak structure in front and behind to allow dosiflexion and plantarflexion, but is strengthened medially and laterally by collateral ligaments (Taser et al. 2006). Ankle stability is based, in part, on both its position and the surrounding ligamentous structures. When the ankle is dorsiflexed, the wider portion lies between the malleoli—this is the closepack or stable position of the ankle. During plantar flexion, the narrow posterior area is in the mortise, permitting some side-to-side movement of the joint, thus increasing its instability. The lateral collateral ligament (LCL) complex of the ankle attaches the lateral malleolus to the talus and calcaneus. The lateral ligament consists of three distinct parts: the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL) and the posterior talofibular ligament (PTFL) (Taser et al. 2006). Sprains of the LCLs account for 85% of all ankle inju- ries that present to the emergency department. Tradition- ally these ligaments are injured in sports where the participants land on a plantar-flexed inverted foot. The ATFL alone, is the most common ligament involved, accounting for up to 80% of LCL injuries; ATFL and CFL injuries together account for approximately 20% of injuries O. A. Raheem (&) Á M. O’Brien Department of Anatomy and Sports Medicine, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland e-mail: omerham@hotmail.com 123 Anat Sci Int (2011) 86:189–193 DOI 10.1007/s12565-011-0109-7