connects the distal tibia and the fibula Excessive external rotation of the ankle when the foot is in dorsiflexion can cause a less common but more severe injury to ankle ligaments known as a high ankle sprain The affected ligaments often include the anterior and/or posterior inferior tibiofibular ligament, the interosseous ligament, and syndesmosis Classification of Ankle Sprains There are many systems of classification for ankle sprains Table 40.4 provides guidelines that can be used in grading injuries to the lateral ligaments FIGURE 40.2 Severe inversion injury FIGURE 40.3 Eversion injury FIGURE 40.4 Juvenile Tillaux fracture or Salter–Harris type III fracture of the distal tibial physis; the medial part of the tibial physis is fused FIGURE 40.5 Anteroposterior and lateral views of three-fragment triplanar fracture L, lateral; M, medial; P, posterior; A, anterior