Flatfoot (flatfoot deformity)

Flat-valgus foot deformity is accompanied by flattening of the longitudinal arch, valgus position of the posterior section, and abduction-pronation position of the anterior section.

ICD 10 code

• M.21.0 Flat-valgus deformity of the feet.
• M.21.4 Flat feet.
• Q 66.5 Congenital flat feet.

Epidemiology of flat feet

Flat feet are a fairly common deformity, accounting, according to various authors, for 31.8 to 70% of all foot deformities. The percentage of flat feet is especially high in preschool and primary school children.

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Causes of flat valgus foot deformity

One of the reasons for the occurrence of flat and flat-valgus feet at this age is considered to be the general weakness of the tendon-muscle apparatus of the lower extremities, as well as dysplastic changes in the skeleton of the foot.

There are a number of theories explaining the etiopathogenetic mechanisms of flatfoot formation:

• static-mechanical theory;
• vestimentary theory;
• anatomical theory;
• theory of constitutional weakness of connective tissue;
• theory of hereditary muscle weakness.

Classification of flat feet

From an etiological point of view, there are five types of flat feet:

• congenital:
• traumatic:
• rachitic;
• paralytic;
• static.

Congenital flatfoot can have varying degrees of severity (mild, moderate and severe). The most severe degree of congenital flatfoot, the so-called rocker foot, occurs in 2.8-11.9% of cases and is detected immediately at birth. The etiopathogenesis of this deformation has not yet been fully studied. The most likely cause of the deformation is considered to be a developmental defect of the rudiment, a delay in its development at a certain stage of embryonic formation. This deformation is considered a congenital deformity.

Acquired flat feet can be:

• traumatic;
• paralytic;
• static.

In recent years, the view on the genesis of static flatfoot has undergone changes and currently has a broader interpretation. Among the examined children with static flat-valgus foot deformity, dysplastic changes in the foot skeleton, combined with neurological symptoms or metabolic disorders of connective tissue, were detected in 78%.

Paralytic flatfoot is a consequence of paralysis of the muscles that form and support the arch of the foot. Traumatic flatfoot is caused by the consequences of an ankle and foot injury, as well as damage to soft tissues and the tendon-ligament apparatus.

There are mild, moderate and severe flat feet. Normally, the angle formed by the lines drawn along the lower contour of the calcaneus and first metatarsal bone with the apex in the navicular bone area is 125°, the height of the longitudinal arch is 39-40 mm, the angle of inclination of the calcaneus to the plane of support is 20-25°, the valgus position of the rear foot is 5-7°. In preschool children, the height of the longitudinal arch of the foot can normally vary from 19 to 24 mm.

In mild flat feet, there is a decrease in the height of the longitudinal arch of the foot to 15-20 mm, a decrease in the angle of the height of the arch to 140°, the angle of inclination of the calcaneus to 15°, a valgus position of the posterior section - up to 10° and abduction of the forefoot within 8-10°.

The average degree of flat feet is characterized by a decrease in the arch of the foot to 10 mm, a decrease in the height of the arch to 150-160°, with an angle of inclination of the calcaneus of up to 10°, a valgus position of the posterior section and abduction of the anterior section of up to 15°.

Severe flatfoot is accompanied by a decrease in the arch of the foot to 0-5 mm, a decrease in the angle of the height of the arch of the foot to 160-180 °, an angle of inclination of the calcaneus of 5-0 °, a valgus position of the posterior section and abduction of the anterior section of more than 20 °. In severe cases, the deformation is rigid, does not respond to correction, and constant pain syndrome is noted in the area of the Chopart joint.

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Conservative treatment of flat feet

Parents usually complain about flat feet in their child when the child begins to walk independently. It is necessary to distinguish between physiological flattening of the arch of the foot of a child who has not yet reached the age of three and flat-valgus deformity, which requires observation by an orthopedist.

If the axis of the heel bone is located along the midline, moderate flattening of the arch of the feet is observed under load in young children, it is possible to limit oneself to massage of the muscles of the lower limbs and wearing shoes with a rigid back. If the child has a valgus deviation of the posterior part and flattening of the arch of the feet, it is necessary to use complex restorative treatment.

Treatment of flat valgus deformity includes massage of the internal muscle group of the shins and feet, plantar muscles in courses of 15-20 sessions 4 times a year, thermal procedures (ozokerite, paraffin, mud applications), corrective exercises aimed at forming the arch of the feet. It is also necessary to introduce exercises into the child's daily routine aimed at strengthening the arch-supporting muscles. This can be achieved using play therapeutic gymnastics, which involves rolling a cylindrical object, walking on the toes and outer parts of the feet, climbing an inclined board, pedaling a bicycle or exercise bike barefoot, etc. Good results in strengthening the muscular system are achieved with active classes in the pool with an instructor in therapeutic swimming training. If the child responds adequately, electrical stimulation of the arch-supporting muscles of the foot is recommended as an aid.

In cases where the feet retain a valgus position even without load, there is tension in the tendons of the peroneal muscle group and extensors of the foot, it is recommended to perform staged plaster corrections in the position of adduction, varus and supination of the foot for 1-2 months, until the foot is brought to the middle position. Subsequently, during sleep, the fixation of the feet with plaster splints or tutors continues for 3-4 months and the provision of patients with orthopedic shoes.

Proper use of special insoles and orthopedic shoes is of no small importance. In children under three years of age, the use of orthopedic shoes is not always advisable, as it limits movement in the ankle joint and is recommended only for the correction of foot deformities in patients with moderate and severe deformities. In case of mild deformities, regular shoes with a rigid back and an insole with a supinator under the heel and a longitudinal arch pad are used. In patients with moderate and severe deformities, orthopedic shoes provide a rigid outer shin and side, an insole under the back section and a longitudinal arch pad. It is important to remember that wearing orthopedic shoes requires regular exercises to strengthen the muscles of the lower leg and foot.

Treatment of severe congenital flat-valgus foot deformity, the so-called rocker foot, should begin in the first days of a child's life, when the tendon-ligament apparatus is not retracted and can be stretched. The difficulty of correction is that the talus, located almost vertically in the ankle joint fork, is rigidly fixed. Staged manual corrections with fixation with plaster bandages should be carried out in specialized orthopedic centers.

Plaster casts are changed every 7 days to correct the deformation until complete correction. If the deformation is corrected, the limb is fixed in the equino-varus position for another 4-5 months, and only then is the child transferred to specialized orthopedic shoes. During sleep, the child is provided with a removable plaster splint or tutor. Long-term rehabilitation treatment is carried out, aimed at correcting the arch of the foot, massage of the arch-supporting muscles, muscles of the lower limbs and trunk. It is possible to use electrical stimulation and acupuncture of the muscles of the foot and lower leg.

Congenital calcaneal valgus foot deformity in children is considered to be the most easily amenable to conservative treatment. This pathology is characterized by significant tension in the anterior tibialis muscle and extensors of the foot, valgus deviation of the anterior section with severe weakness of the triceps surae muscle. The deformity is caused by the incorrect position of the feet in the womb. This is indicated by the heel position of the feet at the birth of the child. The back of the foot touches the anterior surface of the shin and is fixed in this position.

Conservative treatment is aimed at bringing the foot to the equinus and varus positions by means of correction with staged plaster bandages or by applying a plaster splint in the position of equinus and varus foot deformity and adduction of the forefoot. After bringing the foot to the equinus position at an angle of 100-110°, restorative treatment continues: massage of the muscles along the back and inner surface of the shin, paraffin applications to the shin and foot area, exercise therapy, and fixation of the foot with a plaster splint at an angle of 100° is continued during sleep. Children wear regular shoes. The need for surgical treatment is rare and is aimed at lengthening the extensor muscles of the foot and the peroneal group.

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Surgical treatment of flat feet

Surgical treatment to correct the deformity is rarely performed. The percentage of patients operated on in relation to those under observation is no more than 7%. If necessary, tendon plastic surgery is performed on the inner surface of the foot, supplemented by extra-articular arthrodesis of the subtalar joint according to Grice. In adolescents with painful contracture form of flatfoot, the shape of the foot is formed using three-articular arthrodesis.

The optimal age for surgical treatment of severe congenital flatfoot deformity in cases where conservative treatment is unsuccessful is 5-6 months. The following procedures are performed: lengthening of the tendons of the retracted muscles, release of the joints of the foot on the outer, back, inner and front surfaces, open reduction of the talus into the ankle fork, restoration of the correct relationships in the joints of the middle, front and back sections of the foot by creating a duplicate of the tendon of the posterior tibial muscle.