Technique tip: a radiographic projection for an avulsion fracture of the talar attachment of the anterior talofibular ligament.

摘要

Ankle sprain is the most common injury in sports and daily activities. Approximately 5000 and 27 000 cases of ankle sprain are reported in the UK and USA, respectively, per day. Of the anterior talofibular ligament (ATFL), calcane-oflbular ligament, and posterior talofibular ligament, which maintain lateral ankle stability, the ATFL is injured first in the case of an ankle sprain. This injury may be a soft tissue rupture or an avulsion fracture at the ATFL's attachment to the fibula or talus. Although orthopedic surgeons agree that an avulsion fracture is more common at the fibular attachment than at the talar attachment,cadaveric research on ankle sprains has shown a greater likelihood of avulsion at the talar attachment. We believe that one important reason for this discrepancy is that an avulsion fracture at the talar attachment is difficult to diagnose, because an anteroposterior and lateral radiographic view of the ankle cannot reveal the avulsion fragment from the talar attachment clearly; on theother hand, an avulsion fracture at the fibular attachment is easily diagnosed using a routine anteroposterior radiographic view of the ankle. Whether the injury is an avulsion at the talar or fibular attachment including an avulsion fracture or midsubstance rupture, conservative treatment such as cast immobilization, nonweightbearing and the application of a functional brace is usually chosen for an acute injury. However, if conservative treatment fails and there is functional instability of the ankle, surgical treatment is indicated. In the case of avulsion fracture at the fibular or talar attachment, fixation of the avulsion fragment to its origin is performed if possible, but if fixation is impossible because the fragment is too small, resection of the fragment and suture of the avulsion side of ATFL is indicated.