Lateral Ankle Ligament Injury
What is it: The lateral ankle ligamentous complex is made up of three major ligaments, the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), and the posterior talofibular ligament. An injury can involve a sprain or full tear of any of these ligaments. The most commonly injured ligament on the lateral ankle is the ATFL, then the CFL.
How does it present: Patient have usually sustained some type of ankle twisting injury, usually inversion injury. They may have difficulty with walking and have pain and swelling and bruising along the lateral ankle.
Common exam findings: Lateral ankle injuries are graded based on the degree of injury to the ligaments. A minimal ankle sprain may only have pain and tenderness along the lateral ankle. A more severe partial tear of the ATFL or CFL may show tenderness, swelling and some ankle instability. A complete tear of the ATFL may also have a positive Anterior Drawer Sign Test and a complete tear of the ATFL and CFL may have a positive drawer sign and Talar Tilt Test. Associated syndosmosis sprains should be evaluated for with the Calcaneal Squeeze Test and Kleiger’s Test.
Tests and treatment: Ankle x-rays may be needed to evaluated for bony injury. In the acute setting, the Ottawa ankle rules may help determine if x-rays are needed. According to the Ottawa ankle rules, x-rays are only required if there is any pain in the malleolar or midfoot area, and any one of the following: bony tenderness along the distal 6 cm of the tibia or fibula, tenderness at the base of the fifth metatarsal or navivular and an inability to bear weight immediately after the injury and during evaluation. Pain of the fifth metatarsal or navicular should prompt foot x-rays in addition to ankle films. Treatment for more mild sprains is conservative with a period of bracing support followed by functional rehabilitation. Complete tears of the ligaments may require surgical intervention.