Equinus Deformity

Original Editor - Aya Alhindi

Top Contributors - Aya Alhindi, Aminat Abolade and Kirenga Bamurange Liliane

Introduction

Pes Equinus is a condition in which the upward bending motion of the ankle joint (dorsiflexion) is limited. It's also known as tight calf and is typically associated condition of a primary diagnosis of a bunion( Hallux valgus) and most commonly seen in flat foot or pes cavus.In this deformity, an alteration in gait may occur; a patient may also have difficulty climbing stairs, dressing and in lifting the foot up so a patient may need to lift the leg on the affected side up higher, to “step over” the foot.

Classification

Equinus can be classified in multiple ways according to etiology, apex of equinus, spastic and non-spastic forms in addition to soft tissue causes of joint restriction.

Etiology/Causes

Equinus is frequently caused by tightness in the calf muscles (the soleus and/or gastrocnemius muscles) or the Achilles tendon. Some people may have this feature congenitally (existing at birth) or inherited it. Others develop this tightness as a result of wearing high-heeled shoes frequently, being in a cast or using crutches. Other contributing factors include diabetes or having a shorter leg than other. The patient may develop equinus if a bone or bone fragment restricts movement of the ankle (for instance, after an ankle injury). Rarely, calf muscular spasms can induce equinus and may be a symptom of an underlying neurologic condition.Equinus.

Foot Problems Related to Equinus

A number of foot problems can arise depending on how a patient compensates  for their inability to bend appropriately at the ankle, including:

• Plantar fasciitis (arch/heel pain)
• Calf cramping
• Tendonitis (inflammation in the Achilles tendon)
• Metatarsalgia (pain and/or callusing on the ball of the foot)
• Flatfoot
• Arthritis of the midfoot (middle area of the foot)
• Pressure sores on the ball of the foot or the arch
• Bunions and hammertoes
• Ankle pain
• Shin splints

Diagnosis

When people initially contact the doctor, the majority of those with equinus are not aware they have this condition. Instead, they come seeking relief for equinus-related foot issues.

Key diagnostic factors:

• positive family history.
• equinus deformity.
• hind foot in varus and adduction.
• adduction of forefoot.

Other diagnostic factors:

• male sex.
• hip dysplasia.
• neurologic or chromosomal abnormalities.
• smaller lower extremity.

Investigations:

• anteroposterior and lateral radiographs of foot.
• dynamic hip ultrasound.
• pelvic radiographs.
• CT foot.

Special test:

The Silfverskiöld test can be used to differentiate gastrocnemius tightness from an achilles tendon contracture by evaluating ankle dorsiflexion with the knee extended and then flexed.

Non-surgical Treatment

Non surgical treatment strategies are aimed at relieving the symptoms and conditions associated with equinus rather than correcting the deformity itself. Some examples include:

• Night splint
• Heel lifts
• Arch supports or orthotic devices:

Ankle-foot orthoses (AFO) are regarded as an efficient conservative treatment for slowing the progression of equinus deformities because they serve to restrict ankle plantar flexion and offer passive stretching for the tight soft tissues.

• Physical therapy:

Therapeutic interventions such as stretching and active movement of calf muscles are recommended To help remedy muscle tightness.

Surgery

If a bone or tight tendon is restricting the motion of the ankle, surgery may occasionally be required to treat the underlying condition that is causing equinus. There are some risks that are associated with all surgeries, and they differ from patient to patient. Most complications are small, manageable, and unlikely to have an impact on patients.