What is cavus foot?
Cavus foot is a condition in which the foot has an arch that is much higher than normal. As a result of this high arch, a large amount of weight is placed on the ball and heel of the foot when children walk or stand. Their feet become sore at the top and middle and they have trouble finding shoes that fit properly. In addition, the high arches cause children’s ankles to roll outward slightly. This instability can lead to frequent ankle sprains.
What causes cavus foot?
The most frequent cause of cavus foot in children is a nerve or muscle disease. The condition usually is not present at birth but rather develops slowly during the first ten years of life. The most common causes of cavus foot are:
- Charcot-Marie-Tooth disease (CMT)
- Spina bifida
- Muscular dystrophy
- Injuries to the nerves in legs or spinal cord
- Injuries to the leg muscles
Cavus foot also may be an inherited structural abnormality.
Knowing the underlying cause of cavus foot is important because it is likely to get progressively worse when it results from neurological disorders. When cavus foot is not caused by these disorders, it usually does not change in appearance. St. Louis Children’s Hospital’s orthopedic surgeons work closely with pediatric neurologists to discover the cause of a child’s cavus foot in order to treat any underlying disease.
What are the symptoms of cavus foot?
In addition to a visibly high arch in the foot, symptoms of cavus foot include:
- Calluses on the ball, heel or side of the foot
- Bent toes (hammertoes) or claw toes (toes clenched like a fist)
- Pain when standing or walking
- Frequent ankle sprains
How is cavus foot diagnosed?
A diagnosis of cavus foot includes:
- Review of the child’s family history.
- A foot exam to look for a high arch, calluses, hammertoes and claw toes.
- A test of muscle strength in the foot, toes, ankle and leg.
- Observing the child’s walking pattern and coordination.
- Other testing may include electromyogram and nerve conduction velocity (EMG/NCV) studies, blood test for CMT and magnetic resonance imaging (MRI) study of the spine and brain.
How is cavus foot treated?
Cavus foot sometimes may be treated without surgery. These options include:
- Orthotic devices that fit into the shoe to provide stability and cushioning.
- Shoes with high tops to support the ankle and wider heels for stability.
- Bracing to keep the foot and ankle stable.
If these techniques do not help relieve pain and provide stability, two surgeries within the span of two weeks may be needed. During the first surgery, the orthopedic surgeon releases the tightest of the soft tissues in the arch, which causes the rest of the tissues to relax. During the second operation, the surgeon uses a bone graft to reshape at least one bone and moves several tendons to improve muscle balance.