What is an equinus foot and ankle deformity?

An equinus foot and ankle deformity is a condition of the foot and ankle where the foot is held in a downward position; it becomes difficult to pull the ankle and foot up.There is a loss of the upward range of motion of the ankle and foot joint (also called dorsiflexion). In this deformity, an alteration in walking (gait) may occur; a patient may also have difficulty climbing stairs, dressing and getting in and out of cars. With difficulty in lifting the foot up , a patient may need to lift the leg on the affected side up higher, to “step over” the foot as they cannot pull the foot up. This may make it difficult to walk and place stresses on the foot in abnormal places, as well as cause knee, hip or back pain.

What causes an equinus foot and ankle deformity?

There are many causes of an equinus deformity. It is often due to tightening of the Achilles tendon or the two major calf muscles (gastrocnemius and soleus) in the leg. If these muscles are abnormally tight, individuals may be obligated to toe walk. This deformity is sometimes present at birth, and in that case, it is called a congenital equinus deformity.

If it develops later into childhood or as an adult, then it is called an acquired deformity. In regard to the skeleton, excess bone in the anterior ankle or a fracture of the ankle can cause an equinus deformity. Prolonged positioning in equinus, as can happen after a stroke or immobilization, can also lead to rigid deformity.

Nerve damage, particularly of the peroneal or sciatic nerve, can lead to a foot drop, which if not corrected, may develop into a deformity. Trauma, surgery or other neurologic disease may also lead to this condition.

Limb length discripancy is often the underlying cause of unilateral equinus deformity and requires specialized treatment.

How is an equinus foot and ankle deformity diagnosed?

Diagnosis of equinus foot is a clinical diagnosis.

Physical examination of the patient with the knee both flexed (bent) and extended (straight) will allow doctor to determine which muscles are contributing to the problem.

Additionally, X-rays may be ordered to determine if there are bone issues that might be contributing to the condition.

How is an equinus foot and ankle deformity treated?

Depending on the severity of the deformity, treatment may varies :

Conservative Treatment (non-surgical)

Physical therapy entails specific exercises that are used to stretch muscles and achieve better range of motion of the ankle, as well as working on gait training. Often, the calf muscles are a focus of stretching.

Splinting or orthotics may also be recommended. A splint may be worn at night to help stretch the ankle and foot into a more neutral position. Dynamic splinting (a splint with a tension spring) may also be used for correction.

Surgical Treatment

Depending on the cause of the deformity, a surgeon may recommend an Achilles tendon lengthening or a gastrocnemius recession to help with the stretching of the tendons and muscles of the calf. Bone spurs or other bone blocking range of motion may be removed in order to help flex the ankle.