Syndesmosis Injury and Instability, continued [1] [2] [3]

Syndesmosis injuries are liable to be missed unless the clinician is alert to the signs that may present in the patient’s history, the physical exam and the radiographic studies.

In the history be alert to an external rotation injury that is distinct from the usual inversion ankle sprain, either hyperdorsiflexion, pronation eversion, or supination eversion. The athlete may give a history of pain with internally rotating the body over a planted foot, or may have been stepped on or hit while down prone on the turf. Injuries in ski racing, as well as football, soccer and other turf sports more frequently involve the syndesmosis.

On the exam, there may pain directly over the syndesmosis, or a positive squeeze test, which is pain in the syndesmosis with compression of the fibula at mid-calf. The external rotation stress test is performed with the patient seated with the knee flexed and an external rotation force applied to the foot, or with the patient standing with the injured ankle planted and then rotating the body internally. This test is thought to be the most reliable clinical sign.

On the xrays, a Weber C type or Lauge-Hansen PER or SER injury, or a high fibula fracture (Maisonneuve) may be seen. If there is no major fracture, look for avulsion of the inferior lateral tibia or the anterior inferior fibula. Several measurements can be made on the AP and mortise view xrays to evaluate the relationship between the tibia and fibula. These include the medial clear space (MCS), the tibiofibular clear space (TFCS), the tibiofibular overlap (TFO) and the talocrural angle (TCA). Normal findings are shown in the table on the next page.
more>>
this topic [1] [2] [3]