Hollow foot is an abnormal increase in the height of the arched arch of the foot. It is the opposite of flat feet, in which the arch is lowered and flattened. Occurs after foot injuries and in some diseases of the neuromuscular system, less often has a hereditary character. It is manifested by external deformation, pain and fatigue when walking. The diagnosis is made taking into account the examination data, the results of plantography and radiography. Treatment is more often conservative (physiotherapy, exercise therapy, orthopedic shoes), with progressive deformation, surgical intervention is indicated.
Hollow foot – excessive enlargement of the arch of the foot. It is observed in a number of diseases of the nervous and muscular system. It can develop after foot injuries (crushing, severe fractures of the bones of the tarsus), especially those suffered in childhood. Sometimes it is inherited. It is accompanied by rapid fatigue and pain when walking. It causes the formation of calluses and the development of finger deformities. In some cases, it proceeds without any functional disorders.
The reason for going to the doctor is usually intense pain in the feet and the inability to pick up shoes “on the foot”. With a slightly and moderately pronounced hollow foot, conservative therapy is performed. With progressive deformity, surgical intervention is indicated. Traumatologists-orthopedists are engaged in treatment. If the cause of the pathology is diseases of the nervous system, neurologists simultaneously carry out therapy of the underlying disease.
At present, the exact mechanism of the formation of the hollow foot has not been clarified. It is assumed that this pathology usually occurs due to a violation of muscle balance as a result of hypertonicity or paretic weakening of individual muscle groups of the lower leg and foot. At the same time, experts note that in some cases, when examining patients with a hollow foot, it is not possible to confirm a noticeable increase or decrease in muscle tone.
A hollow foot can be formed with a number of diseases and malformations of the neuromuscular apparatus, including polio, muscular dystrophy, spinal dysraphy (incomplete growth of the median suture of the spine), Charcot-Marie-Tooth disease (hereditary sensorimotor neuropathy), polyneuropathy, syringomyelia, cerebral palsy, Friedreich’s ataxia (hereditary ataxia due to damage to the spinal cord and cerebellum), meningoencephalitis, meningitis, malignant and benign tumors of the spinal cord. Less often, pathology develops due to burns of the foot or improperly fused fractures of the calcaneus and talus bone. In about 20% of cases, the factors that provoked the formation of deformation remain unexplained.
The foot is a complex anatomical formation consisting of many elements: bones, muscles, ligaments, etc. All this complex of tissues acts as a single whole, providing support and motor function. Violation of the normal relations between the individual elements of the foot leads to a “failure” of the mechanisms of standing and movement. The load is incorrectly distributed between different departments, the foot gets tired quickly, starts to hurt and deforms even more.
With a hollow foot, the curvature of the longitudinal part of the arch is increased, the first metatarsal bone at the base of the thumb is lowered, and the heel is slightly turned inward. Thus, there is a “twisting” of the foot. Depending on the localization of the most deformed department in traumatology and orthopedics, there are 3 types of hollow foot. In the posterior type, due to the insufficiency of the triceps muscle of the lower leg, the posterior mouth of the plantar arch is deformed. Due to the traction of the flexors of the ankle joint, the foot “goes” into the flexion position, the heel falls below the anterior sections. The posterior type of hollow foot is often accompanied by a valgus deformity resulting from contracture of the fibular muscles and a long extensor of the fingers.
The intermediate type is observed quite rarely and is formed with contractures of the plantar muscles due to shortening of the plantar aponeurosis (with Lederose disease) or wearing shoes with excessively rigid soles. With the anterior type, there is a forced extension of the foot with support only on the fingertips. The anterior arch of the foot is lowered, the heel is located above the anterior parts of the foot. Violation of the relationship between the posterior and anterior divisions is partially eliminated under the weight of the body.
Due to the increase in the height of the arch with all types of hollow foot, the load is redistributed to various departments of this anatomical formation: the middle part is not loaded enough, and the heel hillock and the heads of the metatarsal bones, on the contrary, suffer from constant overload. The fingers are gradually deformed, taking a claw-like or hammer-like shape, the main phalanges are raised up, and the nail ones are strongly bent. Painful corns form at the base of the fingers.
However, an increase in the arch of the foot does not always entail the above consequences. In some cases, a very high arched vault is detected in perfectly healthy people. As a rule, in such cases, the shape of the foot is inherited, is a distinctive family trait, does not cause functional disorders and secondary deformities. In such cases, a change in the shape of the foot is considered as a variant of the norm, no treatment is required.
The patient complains of rapid fatigue when walking, pain in the feet and ankle joints. Many patients note that they experience significant difficulties in choosing comfortable shoes. The examination reveals an increase in the height of the inner and outer arch, expansion, flatness and some reduction of the anterior parts of the foot, deformation of the fingers, as well as painful calluses (more often in the area of the little finger and at the base of the I finger). Often there is more or less pronounced stiffness of the foot.
With a hollow foot due to polio, an indistinct unilateral paresis is usually observed in combination with the equinus of the foot. Muscle tone is reduced, the deformation does not progress. In cerebral lesions, on the contrary, there is an increase in muscle tone, spastic phenomena and increased tendon reflexes. The process is also one-sided, not progressive. In congenital malformations, the deformity is bilateral, prone to progression during periods of increased growth (5-7 years and 12-15 years).
In Friedreich’s disease, the pathology is bilateral, progressive. In the family history, cases of the same disease are usually detected. An increase in the arch of the foot is combined with ataxia, severe gait disorders, mild sensitivity disorders and phenomena of damage to the pyramidal pathways (contractures, spasms and pyramidal signs). In Charcot-Marie-Tooth disease, progressive bilateral deformation of the feet is observed in combination with muscle atrophy, which gradually spreads from the bottom up.
To clarify the diagnosis, radiography of the foot and plantography are prescribed. With a weakly pronounced hollow foot on the plantogram, a protrusion along the outer edge and an excessive deepening of the concave arc of the inner edge are determined. With moderate severity of pathology, concavity extends to the outer edge of the foot. With pronounced deformation, the sole print is divided into two parts. In advanced cases, the contours of the fingers disappear from the fingerprint, which is due to their pronounced claw-like deformation.
If a neuromuscular system disease is suspected, the patient is referred to a neurologist for consultation, a detailed neurological examination is performed, spine x-ray, CT and MRI of the spine, electromyography and other studies are performed. In case of long-standing injuries of the bones of the tarsus, in some cases, a CT scan of the foot may be required. For the first time, a hollow foot detected in the absence of diseases of the neuromuscular apparatus and previous injuries is a reason to suspect a spinal cord tumor and refer the patient to an oncologist for examination.
The tactics of treatment of this pathology is determined by the cause of the disease, the age of the patient and the degree of enlargement of the arch of the foot. With mild and moderate deformities, massage, physiotherapy and physical therapy are prescribed. Unfixed forms lend themselves to conservative correction with special shoes with a raised inner edge without laying out the arch. Pronounced fixed hollow foot, especially in adults, is subject to surgical treatment.
Depending on the cause of development and the type of pathology, osteotomy, wedge-shaped or sickle-shaped resection of the tarsal bones, arthrodesis, dissection of the plantar fascia and tendon transplantation can be performed. Various combinations of these operational techniques are often used. Surgical intervention is performed under general anesthesia or conduction anesthesia in a planned manner in the conditions of a traumatology or orthopedic department.
In most cases, the best option is a combined operation for a Bite or for a Chaklin. The Kuslik method involves redressing or open dissection of plantar aponeurosis in combination with wedge-shaped or sickle-shaped resection of the cuboid bone. After removing the resected area, the front parts of the foot are bent to the rear, and the rear ones are bent in the direction of the sole. The wound is sutured and drained, a plaster boot is applied to the leg for 6-7 weeks.
When performing surgery using the Chaklin method, plantar aponeurosis is also dissected or regressed. Then the bones of the tarsus are exposed, the extensor tendons are removed to the sides, a wedge-shaped resection of the head of the talus bone and part of the cuboid bone is performed. The navicular bone is removed completely or partially, depending on the degree of deformation. With a pronounced omission of the I metatarsal bone, its osteotomy is additionally performed. In the presence of equinus, a tenotomy of the Achilles tendon is performed at the final stage. If the position of the foot could not be completely corrected during the operation, a plaster is applied for a period of two weeks, then the bandage is removed, the final correction is made and the plaster is applied for another 4 weeks.
In addition, in some cases, the Albrecht technique is used to correct the hollow foot, which provides for wedge-shaped resection of the neck of the talus bone and the anterior parts of the calcaneus. With pronounced and progressive deformities, the Mitbreit method is sometimes used – triple arthrodesis in combination with Achilles tendon elongation, osteotomy of the First metatarsal bone and muscle transplantation. Then plaster is applied for 6-7 weeks.
In the postoperative period, physiotherapy, antibiotics, painkillers, massage and physical therapy are prescribed. It is mandatory to use special shoes with a raised outer edge in the rear of the foot and a raised inner edge in the front of the foot. In operations involving muscle transplantation, at the initial stages, rigid boots are additionally installed in the shoes, protecting the transplanted muscles from excessive stretching.