Foot & Ankle

Cavovarus Foot Deformity

Anatomy

Nearly one-fourth of all bones in the human body are in the feet. The foot is a complex, flexible structure that contains bones, joints, and more than 100 muscles, tendons and ligaments, all working together to enable movement and balance. The foot is divided into three sections:

• Forefoot—Has five toes (14 phalanges) and five longer bones (metatarsals). One phalanx of each of the five toes connects to one of the five metatarsals.
• Midfoot—Contains a pyramid-like group of bones, strengthened by tendons, muscles and ligaments to form three curves, or arches (medial, lateral and fundamental longitudinal), at the bottom of the foot. The midfoot includes three cuneiform bones, the cuboid bone, and the navicular bone on top of the midfoot.
• Hindfoot—Includes the heel (calcaneus), which is the largest bone in the foot, and the ankle. The ankle joint contains a small, irregular-shaped bone (talus) located between the heel, lower leg (fibula) and shinbone (tibia). The talus forms a connection between the leg and foot. The Achilles tendon connects the heel and calf muscle, allowing movement such as running, jumping, and standing on the toes.

Difficulties with foot position and function can lead to more serious problems, not only for the feet, but also for other areas, including the spine. In some cases, these problems may be caused by footwear that fits improperly, does not accommodate normal foot alignment, or that interferes with natural movement and balance of the body.

Description

The term "cavovarus" refers to a foot with an arch that is higher than normal, and that turns in at the heel. This is a deformity that tends to worsen gradually over time. Depending on the age of the patient and the degree of deformity and stiffness, treatment options may range from supportive care with bracing, to surgical treatment for soft tissue releases, tendon transfers, and possibly reshaping or fusion of the bones and joints.

Symptoms

As the deformity worsens, there can be increasing pain at the ankle due to recurrent sprains, painful calluses at the side of the foot or base of the toes, or difficulty with shoe wear.

Causes

Weakness in the peroneal muscles and sometimes the small muscles in the foot are often the cause of a cavovarus foot deformity.

Diagnosis

Initially, a careful investigation is needed to rule out any neurological condition that may be causing the foot's high arch. Your doctor will examine your foot and gait, observing as you walk and stand to determine the shape of the arch and heel position. Mobility of the heel will be checked with an exam called The Coleman Block Test, and X-rays may be needed to allow your physician to review the shape of the bones. Often, the bones and joints appear normal other than alignment with the high arch and inward rotation of the heel.

Nonsurgical Treatment

Treatment will depend on what, if anything, is causing pain. Generally, treatment of the foot deformity can involve several options. In mild cases, foot pain can be addressed with orthotics or custom shoes to support and protect the foot and relieve pressure areas. Corns and calluses, if present, can be treated with a regular skin care routine. If appropriate, a foot and ankle conditioning program may be recommended.

Surgery

In severe cases, especially if pain is present and the height of the arch is progressively increasing, surgical treatment may be recommended. This can involve release of contracted soft tissues, tendon transfers to rebalance the foot, osteotomies to reshape the foot, and possibly joint fusions to realign and hold the foot in a corrected position.

With any surgery there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. Your orthopaedic surgeon will speak to you prior to surgery to explain any potential risks and complications that may be associated with your procedure.