Weightbearing Cone-Beam Computed Tomography of Acute Ankle Syndesmosis Injuries

Abstract Syndesmotic injuries are common, but only a subset of these injuries are unstable. A noninvasive tool for identifying instability would aid in the selection of patients for surgery. Weightbearing computed tomography (CT) data have been reported for healthy patients, but there are limited data on unstable syndesmoses. We evaluated the syndesmotic area of arthroscopically proven unstable ankles after acute injury. This is a prospective comparative study of consecutive patients recruited to a weightbearing CT database. Thirty-nine patients were included for analysis with arthroscopically proven unstable syndesmoses and an uninjured contralateral ankle. The syndesmosis area was measured for both ankles, in non-weightbearing and weightbearing positions, and compared. Syndesmosis area of the unstable ankle was significantly greater than the uninjured ankle of the same patient, by a mean of 22.9 ± 10.5 mm2. This was a significantly greater difference than that observed with non-weightbearing CT (9.8 ± 10.2 mm2, p