Cavus Foot Deformity
Now that it’s summer, we spend more time at the beach or swimming pool enjoying the warm weather. As an orthopedic surgeon that specializes in conditions of the foot and ankle, I tend to notice wet footprints across the pool deck or in the sand and cannot help but analyze the health of the individual’s feet. One of the conditions that I notice is the high arched foot, medically termed pes cavus. This is noticeable by a footprint that is pronounced in the heel and forefoot, with very minimal or even absent impression in the middle part of the foot.
Causes of Cavus Foot Deformity
Pes Cavus is caused by muscle imbalances in the lower leg and foot that draws the front of the foot, or sometimes draws the heel downward, making the arch higher than normal. It usually begins during childhood and may be associated with neurological conditions such as muscular dystrophy or spina bifida, but not always. In many cases the muscles of the feet become tighter or weaker for unknown reasons. As with many medical conditions, genetics play a role in who will become afflicted with high arches.
Symptoms of Cavus Foot Deformity
High arches can cause a number of symptoms, ranging from mild to severe. Pain in the forefoot is a common occurrence due to increased weight bearing in this area. Excessive callus buildup at the ball of the foot behind the great toe as well as just behind the fifth toe is common, as these become high-pressure areas during standing and walking. Tightness in the calf muscles is often present, and the individual may also suffer from recurring ankle sprains due to the inwardly rolled ankles associated with the deformity.
Diagnosis of Cavus Foot Deformity
Identifying pes cavus is a straightforward process. The high arched foot is noticeable to anyone, but an orthopedic surgeon should evaluate the individual in order to identify some of the nuances of the condition. Diagnosing which muscles are tight or weak and assessing their potential to be stretched or strengthened is important for initiating an effective treatment plan.
Also, the cavus foot causes increased body weight to be distributed through areas of the foot that are not designed for this purpose. Evaluation by the surgeon will aid in a proper prescription of orthotics, if deemed necessary.
Treatment of Cavus Foot Deformity
Conservative intervention is generally the rule when starting to treat high arches. Often times if the feet have become painful, orthotic inserts are prescribed. As opposed to pes planus (flat feet), which is often a flexible disorder of the foot that we try to correct with orthotics (i.e., push back into the correct position), pes cavus is usually a rigid deformity,meaning that the shape of the foot cannot be changed.
In this case, the goal of orthotics is to accommodate the shape of the foot and to redistribute body weight over a larger area. Because of the rigidity, the cavus foot is not able to flex and absorb impact as the individual walks. For this reason, orthotics are usually constructed of softer materials to act as a shock absorber.
Physical therapy may also be prescribed to stretch and strengthen the muscles of the lower leg. Tight calf muscles and weak muscles along the outside of the lower leg (peroneal muscles) are often present in pes cavus. While therapy cannot change the shape of the foot, it may be able to help with pain control and function. Because the foot is usually rolled inward along with the high arch, the individual is susceptible to chronic ankle sprains and some reactive muscle strengthening may be beneficial, along with ankle bracing.
If conservative treatment fails to achieve the desired result, then surgical correction maybe necessary. There are many types or surgeries that the physician can perform based on individual need:
- Tendon lengthening: This procedure involves making precision cuts in the tight tendons of the lower leg to allow better alignment of the foot. Following surgery,there is a period of immobilization for several weeks to allow the tendons to heal.
- Osteotomy (bone cut/realignment): If the condition has been present since childhood and the bony structure of the foot has grown abnormally, then small sections of bone may need to be removed in order to restore proper position of the foot. The first metatarsal, located in the midfoot behind the great toe, is often treated with an osteotomy. The metatarsal often is positioned at a downward angle that is greater than normal, which in turn rolls the ankle toward the outside of the foot as the person bears weight.
The osteotomy procedure seeks to normalize that angle and place the foot in a neutral position that is perpendicular to the ground. Many times, this osteotomy is performed in conjunction with soft tissue surgery such as tendon lengthening. Also, the calcaneus (heel bone) tends to be oriented toward the midline in pes cavus, as opposed to away from the midline in the normal foot, and sometimes an osteotomy is required to correct this.
- Arthrodesis: Also known as a joint fusion, this procedure permanently locks the affected joint into a fixed position. It is a last resort option, but sometimes necessary when the cavus foot deformity is severe or when arthritis is present.
