Cavovarus Deformity of Foot: Causes, Symptoms, Treatment
What is Cavovarus Deformity of Foot?
Cavovarus Deformity of Foot is the name given to a condition in which an individual has both high arches in the feet as well as a heel which is turned inwards.1 Cavovarus Deformity of Foot is not a common condition and is found very rarely but majority of cases of Cavovarus Deformity of Foot are found in patient with a history of Charcot-Marie-Tooth Disease which is a hereditary condition involving motor and sensory nerves with motor and sensory neuropathy.
Cavovarus Deformity of Foot leads to ankle instability. In some cases, stress reactions and fracture of the lateral bones of the foot and ankle may also occur as a result of cavovarus deformity of foot. Anatomically speaking, the foot gets its stability and balance because of three major structures which are the calcaneus, the first metatarsal head and the fifth metatarsal head.
People with Cavovarus Deformity of Foot tend to have their heel move inwards which shifts the weight of the entire hindfoot inwards. This may lead to the individual having a hyper plantarflexed first metatarsal. This ultimately results in a decrease in the ability of the foot to take the stress and strain of everyday routine and excess stress on the peroneal tendons.
Additionally, Cavovarus Deformity of Foot does not allow the foot to be flat while ambulating resulting in problems with ambulating due to Cavovarus Deformity of Foot.
What Causes Cavovarus Deformity of Foot?
As stated above, Charcot-Marie-Tooth Disease is a major contributor towards development of Cavovarus Deformity of Foot.2 Apart from this, there are other genetic causes which lead to abnormal bone morphology leading to development of Cavovarus Deformity of Foot. Additionally, literature shows that people with increased tendency for stress fractures of the foot are also at risk for developing Cavovarus Deformity of Foot.
What are the Symptoms of Cavovarus Deformity of Foot?
The clinical presentation for Cavovarus Deformity of Foot is people with this deformity will have very unstable ankles causing frequent ankle instability events. Such individuals may also complain of increased incidences of ankle sprains and weakness as well.
Individuals will also be prone to stress fractures due to Cavovarus Deformity of Foot and may complain of lateral foot pain after a change in footwear or after doing some running activity. Also, people who have had a prior surgery to the foot or ankle may complain of painful ambulation and recurrent instability events due to an unrecognized Cavovarus Deformity of Foot.
How is Cavovarus Deformity of Foot Diagnosed?
The best way to diagnose Cavovarus Deformity of Foot is by doing a test called as Coleman Block test.3 This test is done by putting a block of wood or a wedge under the lateral portion of the foot and observing if the hindfoot corrects itself and comes out of varus.
Testing for excessive stress on the peroneal tendon is also done to confirmatively diagnose Cavovarus Deformity of Foot. Other tests to check for instability and peroneal tendon subluxation are also done to confirm the diagnosis of Cavovarus Deformity of Foot.
Treatment of Cavovarus Deformity of Foot
Cavovarus Deformity of Foot can be treated both conservatively and surgically. Nonsurgical treatments for Cavovarus Deformity of Foot involve aggressive physical therapy with calf and plantar fascial stretching. The stability of the ankle can be increased with proprioception exercises at the therapy. The use of Orthotics is also extremely beneficial for treatment of Cavovarus Deformity of Foot. The orthotic of choice is the Coleman orthotic which has shown to be quite effective in the treatment of Cavovarus Deformity of Foot.
Surgical procedures are only recommended for patients who do not respond to conservative treatments for Cavovarus Deformity of Foot and continue to have poor function of foot and ankle region. Surgery is usually recommended for people with Charcot-Marie-Tooth Disease as patients with this disease may not respond favorably to conservative treatments. The lateral ankle instability in individuals with this disease may be treated with a Brostrom procedure which utilized intramedullary nailing.
The defective peroneal tendon may be repaired during this procedure to treat Cavovarus Deformity of Foot.
Another surgical procedure called the first metatarsal osteotomy is also quite an effective procedure to treat Cavovarus Deformity of Foot.
In cases where there is a lack of dorsiflexion of the foot due to the deformity, a tarsometatarsal fusion can be done to get the dorsiflexion back. It is important here to understand that when a surgical procedure is done both the deformity as well as the underlying cause of it needs to be treated together so as to effectively treat Cavovarus Deformity of Foot.