HSS Ultrasound of the Month Case 130

Clinical History 32 year old male with right ankle sprain one week prior.

Ultrasound of the Month – Case 130

1

Ultrasound of the Month – Case 130

2

Diagnosis: Acute ATFL Tear The anterior talofibular ligament (ATFL) is one of three ligaments that make up the lateral collateral ligament complex of the ankle; the other two are the calcaneofibular ligament and the posterior talofibular ligament.

The ATFL is the most commonly injured ligament in the ankle. Ankle “sprain” due to inversion and plantar flexion typically results in tear of the ATFL, followed by the calcaneofibular ligament and then the posterior talofibular ligament.

MRI is traditionally used to diagnose ligamentous injuries in the ankle.

The ATFL is also well evaluated on ultrasound.

On ultrasound, an intact ATFL should maintain a homogenous fibrillar appearance between the distal fibula and the talus.

Torn ATFL will manifest as a diffusely thickened and disorganized bundle of fibers or a frankly discontinuous ligament.

In the chronic phase, a torn and deficient ATFL may manifest as an attenuated or absent ligament.

A torn ATFL which results in instability may require surgical reconstruction.

Ultrasound of the Month – Case 130

3