Ankle Impingement

Anatomy

The ankle joint is hinged, or a ginglimus joint. It is an articulation composed of three bonesthe tibia, the fibula, and the talus. The cartilage that covers the surface of the joint allows for painless movement of dorsiflexion and plantarflexion. Dorsiflexion is movement of the foot toward the head, and plantarflexion is movement of the foot toward the floor. The ankle has many ligaments that help enhance the stability of the joint. These include the deltoid ligament complex, anterior talofibular ligament, calcaneofibular ligament, posterior talofibular ligament, and anterior and posterior tibiofibular ligaments. The names indicate the bone from which the ligaments originate and insert. The joint is shaped like a saddle over the talus. The talus is a trapezoid and is wider in the front than in the back. It is because of this shape, that the ankle is more stable when dorsiflexed (moves away from the ground).

Causes

Anterior impingement is often caused by forced dorsiflexion and activities that incorporate that movement such as soccer or ballet. Bone spurs may develop on the anterior tibia and talus, causing subsequent pain.

Anterolateral impingement is caused by repetitive inversion-type ankle sprains. This causes synovitis or a scar that limits ankle motion in that plane. The repetitive sprains cause overgrowth of tissue in the area, which then impinges on the cartilage surfaces, inducing pain.

Posterior impingement results from the posterior tissues becoming impinged following repeated plantarflexion (downward motion of the ankle). This causes repetitive microtrauma, resulting in inflammation and overgrowth of certain tissues. Activities such as dancing, kicking, gymnastics, or downhill running may predispose an athlete to this condition.

Symptoms

The patient will complain of pain as the primary symptom. The pain will be exacerbated by the movement that corresponds with the type of impingement. Anterior impingement will be worsened by [Page 66]forcing the ankle toward the head or lunging forward with the foot flat on the floor. These patients will also complain of stiffness in their ankle. Anterolateral impingement will cause pain along the anterior talofibular ligament and lateral gutter. They will often have a poor sense of where their ankle is in space, and their symptoms will seem worse with cutting activities. Posterior impingement is a more difficult diagnosis to make, but again the complaint will be pain or catching with push-off or forced plantarflexion.

Diagnosis

The diagnosis always begins with a thorough history and physical examination. Important questions to ask are as follows: When did the pain begin? Is it constant, or does it come and go? Is there a specific injury or trauma that occurred? Where specifically is the pain, and is there a movement that exacerbates it? (The athlete should try and localize the pain with a single finger.) Are there any associated catching, clicking, or mechanical-type symptoms? Has any treatment been tried that makes the pain better or resolves it? The physical exam begins with visual inspection for any obvious swelling or deformity. The ankle is palpated for tender areas. Neurovascular status is assessed. This includes palpation of the dorsalis pedis and posterior tibial pulse as well as assessing the sensation over the top and bottom of the foot and the first web space. Movement of the ankle and subtalar joint is assessed. This includes dorsiflexion, plantarflexion, inversion, and eversion. The patient with impingement may complain of pain at the extreme of one of these motions.

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