Cavus foot syndrome (lat. pes cavus) is characterized by an excessively high longitudinal arch of the foot. People with this condition place too much stress on the heel and toe when walking and/or standing.
The spectrum of deformities associated with pes cavus includes torsion (especially the big toe), hindfoot deformity (characterized by an increased heel angle), and contracture of the plantar fascia. They lead to an excessively high load on the heads of the metatarsal bones, which can result in calluses and metatarsalgia.
Etiology
The occurrence of cavus foot may be associated with pathological processes in the brain and spinal cord, in peripheral nerves, or with structural problems of the foot. If a muscle imbalance occurs in the foot before the final formation of the skeleton, significant changes in the morphology of its constituent bones can be observed. If the deformation occurred after reaching skeletal maturity, then usually the morphology remains the same or undergoes minor changes. Two thirds of adult patients acquire cavus foot due to neurological diseases such as peroneal muscular amyotrophy (Charcot-Marie-Tooth disease), spinal dysraphism, polyneuritis, intraspinal tumors, poliomyelitis, syringomyelia, Friedreich's hereditary ataxia, cerebral palsy and spinal tumors that can cause muscle imbalance leading to an enlarged arch. A patient with a newly diagnosed unilateral foot deformity who has not had a history of trauma should be evaluated for the presence of spinal tumors.
Hollow foot: what to do, how to treat?
The first thing to do when you discover a cavum foot in yourself or your child is to seek qualified medical help. It is best to make an appointment with an orthopedist right away. In Moscow, a free consultation with this specialist can be obtained at our manual therapy clinic.
After an examination and an accurate diagnosis, an individual course of treatment is developed. Most often, treatment of cavus foot is carried out using conservative methods. Surgery may be required only in advanced cases or with rapid progression of the pathology.
In our manual therapy clinic, treatment of cavus foot is carried out on adult patients and children over the age of 5 years. For this we use the following methods:
- therapeutic exercises and kinesiotherapy - allow you to strengthen the muscles that are antagonists of the muscles of the longitudinal arch of the foot and thereby compensate for their excessive tension;
- physiotherapy stimulates restoration processes in damaged tissues;
- osteopathy and massage restore normal microcirculation of blood and lymphatic fluid in the affected areas;
- laser exposure may be required when identifying foci of destruction in the area of small joints of the foot;
- electromyostimulation allows you to quickly eliminate excessive tension in certain muscle groups and increase the tone of weakened myocytes;
- Reflexology is used to launch regenerative processes in the human body.
The course of treatment is always developed individually. Therefore, we recommend that you make a free appointment with a doctor and receive individual recommendations for complex therapy.
Forms of cavus foot syndrome
Three main types of foot cavus syndrome have been described in the literature: pescavovarus, pescalcaneocavus, and true pescavovarus. These three types can be distinguished by their etiology, clinical signs, and radiological findings.
- Pes cavovarus or adducted foot, the most common form of pes cavus, is seen primarily in neuromuscular disorders such as CMT and, in cases where the etiology cannot be determined, is usually termed “idiopathic.” Pes cavovarus is characterized by an externally rotated calcaneus, plantar flexion of the first metatarsal, and curled toes. Radiological examination performed for pes cavus caused by CMT usually shows a plantar flexed position of the toe relative to the heel.
- Pes calcaneocavus or pes calcaneocavus usually occurs with triceps surae paralysis caused by polio. This case is characterized by a dorsally bent calcaneus and a plantarly bent toe. Radiological images demonstrate a large talocalcaneal angle.
- “True” pes cavus is characterized by a lack of dorsal flexion or outward rotation of the calcaneus, as well as an excessively high longitudinal arch due to plantar flexion of the toe relative to the heel. The combination of any of these features forms the so-called “combined” cavus foot, which then either retains mobility or loses it.
In addition, there are four types of cavus foot syndrome in accordance with the position of the highest point of the longitudinal arch: anterior (toe), metatarsal, posterior and combined.
Symptoms of the disease
At the beginning of the pathology, a person complains of weakness and pain during movements and at rest. It also becomes difficult to find comfortable shoes.
Calluses and corns appear in the area of the fifth toe and at the base of the big toe, causing pain, and restrictions in the movement of the foot are noted.
Cavus foot in combination with polio disease has a unilateral disorder with decreased muscle tone. With cerebral damage, muscle tone is increased along with tendon reflexes.
Pathogenesis
A large number of theories have been proposed to describe the pathogenesis of pes cavus syndrome. Duchenne and co-workers linked the occurrence of high arches to intrinsic muscle imbalances. Other theories focus on the extrinsic muscles and the combined action of the intrinsic and extrinsic muscles to cause imbalance.
Mann et al (1992) in their work described the pathogenesis of pes cavus syndrome caused by CMT. The nature of the deformation, according to their assumption, should be determined by the interaction of agonist and antagonist muscles. With CMT, the tibialis anterior and peroneus muscles weaken. At the same time, the antagonists - the tibialis posterior and peroneus longus muscles - begin to surpass other muscles in strength, pulling the foot towards itself and thereby deforming it. Specifically, the peroneus longus muscle inhibits the action of the tibialis anterior muscle, causing plantar flexion of the first metatarsal and toe valgus. The tibialis posterior muscle dominates the peroneus brevis muscle, promoting toe adduction. Simultaneously with the contractures that arise in the internal muscles, the long extensor of the toes is involved in the process of dorsal flexion of the ankle, which provokes twisting of the toes. Increased stress may be placed on the lateral ankle ligaments if the toe is turned outward and the heel is turned inward, which can subsequently create a risk of loss of balance.
Diagnosis of flat feet
We list the methods that doctors use to make a diagnosis.
X-ray is one of the most accurate ways to determine the type and degree of flat feet. X-rays of both feet are taken in two projections.
Plantography is a technique that can be performed at home. A rich cream is applied to the feet, the person stands on a piece of paper with both feet, and then the print of the feet is examined. Doctors use Lugol instead of cream, which provides a more accurate print.
Friedland's technique is the measurement of the width and length of the foot using a podometric index, which allows one to determine the type and degree of flatfoot.
Clinically Relevant Anatomy
From a clinical point of view, the cavus foot is characterized by an abnormally high height of the longitudinal arch. From a biomechanical point of view, a hollow foot is formed by an inwardly turned toe, a large heel angle, a high midfoot, and plantar flexion of the toe.
When the talocalcaneal angle decreases, the navicular bone is located superior to the cuboid bone, rather than in the middle. This leads to difficulty operating the Chopart joint. The navicular bone connects the foot and ankle. A healthy foot rotates around the navicular bone, in turn, the cuboid bone always moves simultaneously with the heel bone.
Advantages of custom orthotics
Each person’s foot is a unique structure that has individual parameters and relief. A person turns to an orthopedist with various deformities, so it is logical that insoles should be made individually. Such products are created based on a three-dimensional (3D) model of the plantar foot. This distinguishes them from ready-made arch supports, which are most often created according to the principle of “one shape fits all.” Among the disadvantages of custom orthotics is the high cost when compared with factory insoles. You can also quickly buy ready-made insoles at any specialized store, while examining your feet and making individual insoles will take time. But custom-made insoles, made from high-quality and highly durable materials, will last you much longer than ready-made ones - up to 15 years.
Characteristic
During the stance phase of the gait cycle, the heel is in an inverted position and the toe is in a varus position, which leads to insufficient load distribution across the foot. This can lead to metatarsalgia, first metatarsal stress fractures, plantar fasciitis, medial longitudinal arch pain, iliotibial tract syndrome, and loss of balance.
In cavus foot syndrome, the calcaneus rotates internally under the talus, resulting in a small talocalcaneal angle. Because the calcaneus is followed by the cuboid, the latter ends up in a plantar position relative to the scaphoid rather than adjacent to it. This position leads to blocking of the middle part of the foot and overload of its lateral part.
The mobility of the foot can be assessed differently by looking at it from the front and drawing a mental straight line along the foot through the Lisfranc and Chopart joints. The parallelism of this straight surface is a condition for free flexion of the foot. As the angle between the straight line and the surface increases, the mobility of the foot decreases noticeably. In the case of very high longitudinal arches, the load is distributed unevenly along the metatarsal heads and the lateral border of the foot. This can cause pronation of the foot and injury to the heel bone due to excessive pressure, as well as the formation of osteophytes at the junction of the metatarsals and cuneiform bones.
Orthopedic insoles for heel spurs
Orthopedists recommend adhering to the following rules when choosing insoles for patients with heel spur disease:
- The structure must be equipped with an instep support, a rigid frame that will support the foot and distribute the load evenly;
- It is necessary to have a heel shock absorber that compensates for dynamic loads;
- In some cases, an insole with wedges located under the heel is selected (if supination or pronation of the foot is noted).
Symptoms and clinical manifestations
Signs of cavus foot syndrome are patient complaints of pain in the foot (especially in its lateral part due to increased load), loss of balance, problems with movement and wearing shoes. The nature of symptoms may vary depending on the deformity. The main symptoms of pes cavus include disorders such as:
- metatarsalgia;
- pain under the first metatarsal bone;
- plantar fasciitis;
- painful calluses;
- ankle arthritis;
- inflammation of the Achilles tendon.
Other symptoms include:
- keratosis;
- lateral destabilization of the ankle joint;
- varus position of the heel;
- plantar toe flexion;
- stress fractures of the lower extremities;
- knee pain;
- iliotibial tract syndrome;
- backache;
- loss of stability.
Prevention and treatment of foot deformities and diseases
Treatment for flat feet in children and adults is different. Children's flat feet are completely curable, as the body is still growing. The most important thing is to detect the pathology in time and take action.
The main goal of treating flat feet in adults is to stop the progression of the disease.
Treatment of flat feet in children
When treating flat feet in children, it is taken into account whether the pathology is congenital or acquired.
For congenital foot disease, splints and plaster casts are used.
For acquired flat feet, treatment is aimed at strengthening the musculo-ligamentous system. For this purpose, massage, therapeutic exercises, contrast dousing of the feet, walking on sand, pebbles and special massage mats are prescribed. Wearing orthopedic insoles and shoes is definitely recommended.
Treatment of flat feet in adults
Treatment of foot deformities in adults is aimed at relieving pain and normalizing tone in the foot ligaments and muscles.
To treat flat feet, medications are used that relieve pain in the legs and have an anti-inflammatory effect. Basically, doctors prescribe non-steroidal anti-inflammatory drugs such as diclofenac, ibuprofen, etc.
A good effect is achieved by foot massage, which eliminates swelling in the limbs and increases vitality. Exercise therapy and warm sea salt foot baths may be recommended.
If severe foot deformity is observed, surgical treatment is performed.
Treatment
The treatment of cavus foot syndrome is to return the patient to the ability to move without any problems and pain. The patient must understand that surgery cannot completely correct foot deformity. The main goal of surgical treatment is to increase the contact area between the foot and the surface, as well as to relieve pain. Repeated surgical procedures may be necessary, especially if the foot deformity progresses. Surgical procedures are performed on both soft tissue and bone. Tendon transposition and osteotomy practiced within their framework make it possible to correct the deformity without the need for arthrodesis.
Clinical tests
To assess the mobility of the subtalar joint, the Coleman block test is used. A wooden block 2.5 mm thick is placed under the outer part of the foot, its first metatarsal bone hangs from the block and is plantar bent. If the heel returns to a neutral position from an inward or outward rotation, then the joint is mobile. Otherwise, he turns out to be tough. In addition, the heel angle is also measured as part of the clinical tests.
Physiotherapeutic treatment
Proposed conservative treatment strategies typically include methods to reduce and redistribute plantar loads using foot orthoses and specialized shoes with supportive cushions. The orthosis used must perform the following tasks:
- Increase the contact area of the sole of the foot with the surface. Overloading of the metatarsal heads is the result of little contact between the sole and the surface due to an excessively high arch and limited dorsal flexion of the ankle. Increasing the contact area helps transfer load from the metatarsal heads to the arch of the foot (Level of Evidence: 4).
- Prevent excessive foot supination. Lateral displacement of the ankle and subtalar joint axis is often associated with the formation of pes cavus. This position leads to increased torque of the supinator muscle around the axis of the subtalar joint.
- Counteract underpronation and supination. Destabilization of the heel is caused by a lateral displacement of the axis of the subtalar joint. In the mobile form of pes cavus syndrome, excessive elasticity of the transverse tarsal joint complicates the final stage of the support phase of the gait cycle. The pathological condition of the toe of the foot contributes to supination of the transverse tarsal joint, leading to excessive pronation of the heel. Some patients with pes cavus suffer from both lateral ankle destabilization during the stance phase and heel pronation during the final stance phase. Stretching and strengthening of tight and weak muscles, debridement of plantar calluses, bone mobilization, massage, and chiropractic manipulation of the foot and ankle may be helpful in treatment (Level of Evidence: 5).
- To level a high arch of the foot and prevent rubbing of the toes, it is possible to use various orthopedic devices, in particular, orthopedic shoes with a sole that follows the arch of the foot. In case of varus deformities, it is possible to modify the shoes with an orthopedic wedge. The use of a splint for foot drop or mild deformities may allow the patient to ambulate; however, for patients with reduced foot sensation, the use of foam-lined splints and frequent skin inspection for ulceration are recommended (Level of Evidence: 1b).
Surgery
Surgical methods for combating pes cavus syndrome are mostly based on tendon transposition. They include the following approaches:
- Correction of pes cavovarus.
- Correction of plantar flexion of the first metatarsal through artificial dorsal flexion.
- Correction of varus position of the foot using lateral osteotomy of the calcaneus.
- Arthrodesis of the tarsometatarsal/subtalar joints.
- Arthrodesis of the first tarsometatarsal joint, lateral osteotomy of the calcaneus.
Operations on bones.
If the deformity is elastic (negative Coleman test), a dorsal wedge-shaped osteotomy of the base of the 1st metatarsal bone is performed.
In case of rigid varus deformity of the calcaneus (positive Coleman test), its valgus osteotomy is performed. Always performed in combination with the above soft tissue interventions and osteotomy of the base of the 1st metatarsal bone.
In cases of severe rigid deformity, triple arthrodesis may be required.