Anterolateral impingement of the ankle

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Anterolateral ankle impingement is one of the impingement syndromes of the ankle and can occur as a posttraumatic sequel of an inversion injury .

Terminology

Anterolateral ankle impingement has been known under the term anterolateral 'meniscoid lesion', which is the result of synovitis in the anterolateral gutter.

Epidemiology

It is an uncommon cause of chronic lateral ankle pain , typically seen in athletes . It is associated with a previous ankle sprain or anterior talofibular ligament injury in leading to this condition in 2-3% .

Clinical presentation

Patients usually present with anterolateral ankle pain, limiting the range of motion during internal and/or external rotation and dorsiflexion and swelling with clinical examination being a pretty good predictor .

Pathology

Anterolateral capsular thickening, hypertrophic scarring or a synovial meniscoid lesion will result in anterolateral ankle impingement . This can happen as a sequel to different causes .

Etiology

a rare sequel of an anterior talofibular ligament tear with hemarthrosis and subsequent synovitis
thickening of the accessory anterior inferior tibiofibular ligament or Bassett's ligament
anterior tibiofibular syndesmosis injury
repetitive microtrauma with subsequent instability
anterolateral tibial plafond osteophytes

Radiographic features

Anterolateral ankle impingement is characterized by a soft tissue thickening and distortion of the anterolateral recess of the ankle joint .

Plain radiograph/CT

Useful to evaluate bony proliferations and/or osteophytic spurs at the anterolateral tibial plafond or osseous bodies projecting on the anterolateral gutter.

US

Hypoechoic, on color Doppler hyperemic soft tissue mass and capsular nodules within the anterolateral gutter .

MRI

Soft tissue thickening, obstruction and distortion of the anterolateral gutter sometimes with avulsed fragments or osseous bodies within the can be seen. Thickening of the accessory anterior inferior tibiofibular ligament or abnormalities such as thickening of the anterior talofibular ligament can be identified.

The actual role of MRI, however, is to exclude important differential diagnosis e.g. chondral or osteochondral lesions of the lateral talar dome.

Signal characteristics

Refers to typical signal characteristics of a 'meniscoid lesion':

T1: intermediate to low signal intensity

T2/PD: intermediate to low signal intensity

STIR/PDFS: intermediate intensity

T1 C+: avid enhancement of the synovia

CT/MR arthrography

Nodular thickening oft he anterolateral recess .

Treatment and prognosis

Initial treatment is usually conservative with rest, physical therapy, taping, shoe modifications, nonsteroidal anti-inflammatory drugs and local corticosteroid injections, in conservative treatment failure management is usually arthroscopically .