High ankle sprains.

A) Anatomy:

 Anterior (left) and posterior (right) 3D renderings of the syndesmotic ligaments at the ankle demonstrate the anterior inferior tiobiofibular ligament (AITFL), the posterior inferior tibiofibular ligament (PITFL), transverse tibiofibular ligament (TrTFL) and the interosseous membrane (IM).

 Contiguous axial fast spin-echo T2-weighted images from the same patient.  (6a) The TrTFL is partly visualized as a thick hypointense band posterior to the talar dome (arrow).  (6b) The AITFL (arrow) and PITFL (arrowhead) are both visible on an axial image through the tibiotalar joint.

 Axial fast spin-echo T2-weighted image approximately 2 cm above the tibial plafond. The interosseous ligament, which is the lower margin of the interosseous membrane, is visible as a thin linear hypointense band extending from the tibia to the fibula (arrow).

Contiguous coronal fat suppressed fast spin-echo images in the same patient.  (10a) The PITFL is visible as a striated, triangular structure which is relatively narrow at its fibular insertion(arrowhead) and wider at the tibial attachment (arrows).  (10b) Just anterior to image 10a, a small amount of joint fluid protrudes superiorly into the normal interosseous synovial recess (arrow). The interosseous ligament is the lower margin of the interosseous membrane, and is visible as a transverse bandlike structure at the upper margin of the synovial recess (arrowheads).

Coronal fat suppressed T2-weighted image in a patient with a tibiotalar effusion. Joint fluid separates the PITFL (arrows) from the more inferior TrTFL (arrowheads). In many patients, these two ligaments are not well delineated from each other due to their proximity.



B) Pathology:

Complete tear of the AITFL with interosseous ligament sprain in a 22 year old male after wakeboarding injury.  (12a) Axial fast spin-echo T2-weighted image demonstrates complete AITFL tear. The torn ligament fibers are clumped into a round hypointense object with irregular margins (arrow).  (12b) Coronal fat suppressed fast spin-echo proton density-weighted image in the same patient shows edema extending craniad into the interosseous ligament and interosseous membrane (arrows), indicating sprain.

Football injury 2 weeks ago in a 26 year old male.  (13a) Axial fast spin-echo T2-weighted image through the tibial plafond demonstrates complete tear of the AITFL (arrow) and partial tear of the PITFL (arrowhead).  (13b) Coronal fat suppressed fast spin-echo proton density-weighted image through the interosseous ligament shows complete tear of the ligament with edema extending superiorly in the interosseous space (arrows). (13c) Coronal fat suppressed fast spin-echo proton density-weighted image through the PITFL again demonstrates high grade partial tear of the ligament at the tibial insertion (arrows).

Axial T1-weighted image showing ossification of the anterior and posterior syndesmotic ligaments (arrows) in a 31 year old male after previous left ankle syndesmosis injury several years ago.


Reference