Acute ankle injury and chronic lateral instability in the athlete Benedict F. DiGiovanni, MD * , George Partal, MD, Judith F. Baumhauer, MD Department of Orthopaedics, University Of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA Acute ankle injuries Ankle sprains are the most common injuries in sports and recreational activity, accounting for 40% of all athletic injuries, especially in basketball, soccer, cross- country running, dance, and ballet [1]. Ankle injuries make up 10% of all visits to the emergency room [2]. Ankle sprains account for 53% of injuries in basketball players and 29% of all extremity injuries in soccer players, and account for the most common trauma in modern dance and classical ballet [3,4]. In football, approximately 12% of all time lost to injuries is secondary to ankle injuries [5]. Three quarters of ankle sprains involve the lateral ligament process. Within specific sporting activities, the incidence is equal for males and females [5]. Ankle ligament anatomy and biomechanics Stability of the ankle depends on its passive or ligamentous supports as well as its muscular (peroneals) or active support. The ankle ligaments can be divided into three groups: lateral ligaments, medial ligaments, and the ligaments of the syndesmosis. The most common injuries involve the lateral ligaments. The lateral ligamentous complex consists of the anterior talofibular (ATFL), calcaneofibular (CFL), posterior talofibular (PTFL), and lateral talocalcaneal (LTCL) ligaments. The PTFL and LTCL are less commonly injured during 0278-5919/04/$ – see front matter D 2004 Elsevier Inc. All rights reserved. doi:10.1016/S0278-5919(03)00095-4 * Corresponding author. E-mail address: benedict_digiovanni@urmc.rochester.edu (B.F. DiGiovanni). Clin Sports Med 23 (2004) 1 – 19