Orthopedics - Oleksa A.P. 2006

Congenital and acquired deformities of the lower limb
Orthopedic foot deformities
Flat-valgus foot

The occurrence of acquired Flatfoot with a valgus deviation of the FOOT in 80% of cases is caused by static disorders. Initially, Muscle equilibrium is preserved, but over time, the balance of static force directions is disturbed; this serves as the primary cause of flatfoot, and subsequently of acquired flat-valgus foot deformity (Fig. 206).

For a certain period, compensatory mechanisms delay the progression of the deformity; however, under METABOLISM/18.html">The Influence of loads, the talus displaces medially and downwards, resting its HEAD on the calcaneonavicular ligament.

Abduction of the distal foot causes a valgus position of the foot. M. tibialis posterior stretches and loses its ability to correct this deformity.

The pronated position of the foot shifts the load-bearing onto its medial border, which diminishes or eliminates the normal longitudinal medial arch.

If the foot deformity progresses, the talar head will displace even further medially and descend all the way to the floor, resulting in bone deformation and secondary Changes in the JOINTS OF THE foot, particularly in articulatio talonavicularae, as well as alterations in the ligamentous apparatus and Muscles.

Makarova M.S. and Konyukhov M.P. (1990) note that in examined children aged one to ten years with flat-valgus feet, a decrease in muscle tone and increased joint mobility of the feet were observed. At rest, the feet maintained a normal shape, with a radiologically normal height of the longitudinal arch (143.8+1.3°) and bone positioning without deviations from the norm. Under load, the feet assumed a flat-valgus position, and the arch became undefined. In severe cases, a bulge on the medial side of the foot in the arch area and abduction of its distal part were revealed.

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Fig. 205. Determination of the foot arch height from a radiograph (schematic drawing).

Fig. 206. Flat-valgus feet: a - view from the medial side, b - from the lateral side, c - from the rear.

X-ray Examination of children in a standing position reveals a 12-15° decrease in the height of the longitudinal arch, a pronated position of the calcaneus, and a subluxation in the subtalar joint.

Congenital flat-valgus feet are detected at birth in 2.8-18% of cases.

Clinical Features. The initial signs of a flat-valgus foot can be detected when the patient is in a standing position, i.e., under foot load. Inspection reveals valgus deviation of the heel, a diminished medial longitudinal arch, slight abduction of the distal foot, a medially protruding talar head visible from the front and slightly below the medial malleolus, and Skin callosities in this area.

Upon examination, movements in the ankle joint are normal, but there is limited supination in the subtalar joint when the patient is standing, although this may not be apparent without foot load in a compensated state.

Pain is localized in the areas of the bone-Ligamentous apparatus of the foot, its muscles and tendons, and even in the ankle joint. The pain is caused by the improper positioning of the talus, navicular, and calcaneus bones during weight-bearing, the stretching of ligaments—especially ligamentum calcaneonaviculare, against which the talar head abuts—as well as improper loading of the metatarsal heads.

It should be emphasized that valgus deviation of the foot alters the static conditions of the lower extremity, which may later lead to functional Disorders of the knee and even the hip joint.

Features of flat-valgus foot deformity in children. Flatfoot is quite frequently detected in children and is considered physiological up to the age of three, as thick subcutaneous adipose tissue conceals the normal foot arch.

During the first year of life, before the child begins to walk, the foot is shaped under the influence of muscle tension, and later—As a result of weight-bearing when static factors come into play.

When the child starts walking, the yet undeveloped coordination of foot Muscle Function fails to provide proper load distribution on the foot and its formation. This is why flatfoot in children should not be considered a pathological deformity—it completely disappears by four to five years of age.

However, the presence of valgus foot deviation with weight-bearing on its medial border should alert the physician, as the deformity may progress. Flat-valgus foot deformity in children does not cause them anxiety or pain, nor does it lead to transverse flatfoot.

Nevertheless, there are cases where children aged 10-14 exhibit limited pronation and supination Movements of the foot with normal ankle joint mobility. The restriction of these movements may be congenital due to a bony bridge between the calcaneus and navicular bones or their fibrous connection. The direct cause of acquired deformity is contracture of the peroneal muscle group, which blocks movement in articulatio talocalcanea; at this age, this is caused by accelerated bone growth relative to lagging muscle growth.

Clinically, this manifests as flatfoot with a lowered medial longitudinal arch of the foot. The heel and distal foot are abducted, sometimes with pronation, and tense tendons of the peroneal muscles are visible beneath the skin. Additionally, m. tibialis posterior sometimes reflexively contracts, which collectively severely limits supination and pronation of the foot.

It should be noted that under anesthesia, muscles relax, making it possible to detect a full range of motion. If this restriction of movement persists under anesthesia, one can suspect structural congenital or acquired secondary foot defects.

Flat-valgus foot in adults. Flat-valgus foot in adults exhibits all the typical clinical signs mentioned above.

Two Types of this foot deformity should be distinguished.

The late form of flat-valgus foot remains asymptomatic and painless for a long time. The main clinical sign is a slow, progressive increase in the valgus deviation of the foot, which eventually deforms footwear. The cause of this progressive deformation is sometimes difficult to establish. Occasionally, it is triggered by weight gain, reduced endurance of the ligamentous-muscular apparatus of the foot in older individuals, occupational static loads, or diminished physical strength resulting from chronic illness. Patient Complaints of foot fatigue and pain usually appear quite late.

The second form of flat-valgus foot in adults is caused by significant structural changes and functional disorders. It typically results from untreated flatfoot during adolescence, which eventually leads to irreversible secondary alterations in the foot.

Clinically, this type of flat-valgus foot manifests as pronounced valgus deviation and flatfoot, the absence of normal medial longitudinal and transverse arches, stiffness in the subtalar joint, and toe deformities (frequently Hallux Valgus). As a rule, painful corns develop in the region of the prominent, medialized, and displaced talar head, as well as on the sole beneath the depressed head of the second metatarsal bone.

Foot function is significantly impaired, and its endurance is reduced. During walking, the push-off phase is absent, resulting in a heavy and labored gait with slightly bent knees. This contributes to The Development of secondary deforming gonarthrosis. Frequently, foot alterations are accompanied by trophic disorders, edema, and varicose Veins.

Flat-valgus foot is frequently observed in patients with Rheumatoid Polyarthritis. Due to inflammatory processes in the Structure/83.html">Structural elements of the foot and a significant decline in the function of m. peroneus longus and m. tibialis posterior, which support the medial longitudinal arch, flatfoot develops initially, followed by pes plano-valgus.

Due to involvement of the metatarsophalangeal joint, the patient attempts to relieve pressure on this painful joint; with a weakened peroneal muscle, they elevate the head of the first metatarsal bone, which flattens the longitudinal arch and supinates the metatarsal region.

The elevated head of the first metatarsal bone deprives the foot of its primary support point. Consequently, to establish support, the patient flexes the first toe, which elongates the foot arch anteriorly or forces it into a valgus position with simultaneous abduction of the Metatarsal Bones—manifesting clinically as a flat-valgus foot.

A similar mechanogenesis of this foot deformity occurs in tenosynovitis of the peroneus longus muscle, which reduces or eliminates the support provided by the head of the first metatarsal bone. Furthermore, decreased Stability of the talonavicular joint on the medial side of the foot is promoted by tenosynovitis of the m. tibialis posterior. The metatarsal bones shift laterally (abduct), while the talar head descends and presses against the calcaneonavicular ligament, creating a typical flat-valgus foot. The foot becomes rigid, inelastic, and inflexible. Restriction of supination and pronation movements causes pain during walking, particularly on uneven terrain.

Treatment. Management of flat-valgus foot depends on the Etiology and mechanogenesis of the deformity.

In static flatfoot, the most crucial measure is strengthening the foot muscles, especially those supporting the medial longitudinal arch. This is achieved through massage and Therapeutic Exercises (PT); children are encouraged to walk barefoot on textured surfaces (on dry ground, indoors, or on a board filled with wheat or rice grains, etc.), and during the summer, along the seashore over fine pebbles. Additionally, arch Supports (orthotics) are prescribed for everyday footwear. It must be emphasized that orthotics alone, without physical exercises, do not improve the functional state of the muscles. Passive support of the longitudinal arch solely via orthotics is largely ineffective and temporary.

In cases of flat-valgus foot with structural alterations, The Use of arch supports is inappropriate.

Depending on the structural changes in the talocalcaneal and talonavicular joints, as well as the Base of the first metatarsal bone, the treatment of flat-valgus foot can be either conservative or surgical.

Conservative treatment is employed in the early Selection/3.html">Stages of development and progression of the deformity. The primary goals are to correct the foot deformity and prevent the progression of recurrence. The complex of conservative measures includes: 1) manual redressement and massage of the leg and foot muscles, which should be performed daily over an extended period; 2) warm saline or coniferous baths, and swimming; 3) physical therapy Procedures (ozokerite-paraffin Applications, UHF therapy); 4) therapeutic exercises; 5) high-top orthopedic shoes that restrict pronation-supination movements of the foot, equipped with an insert custom-molded by a prosthetist to match the existing deformity.

When deformity progresses and conservative treatment proves ineffective, accompanied by pain and impaired static-dynamic function of the foot, Surgical treatment is indicated. In children aged 10–14 years, surgery is performed using the Miller technique: double resection of the Tarsal Bones (Fig. 207).

The simplest surgical Procedure yielding satisfactory functional results is subtalar arthrodesis with relocation of the calcaneus into a normal position.

Surgical Technique. Under general anesthesia using a tourniquet, a lateral Kocher incision is performed, beginning posterior to the lateral malleolus and extending in an arc inferior to it as far as the cuboid bone. After exposing the peroneal tendons located adjacent to the lateral malleolus, they are luxated and retracted upward and anteriorly. The ligaments and Joint Capsule are incised in the PROJECTION OF THE joint space between the talus and calcaneus. Using an osteotome and gradually supinating the foot, the articular surfaces of these bones are sparingly resected, taking into account the normal Böhler angle of the foot. Following resection, the correct position of the foot, the anatomical relationship of the bones, and the adaptation of the resected surfaces are verified once more. Occasionally, the adapted bones are fixed with Kirschner wires inserted percutaneously from the sole. The peroneal tendons are replaced in their anatomical bed, and the fibrous Tissues retaining them are sutured. The wound is closed in layers, and a plaster boot is applied up to the upper third of the leg.

The next day, the wound is dressed, and after its healing, the wires are removed in 2–3 weeks. The plaster boot is discarded once bony ankylosis is achieved.

Fig. 207. Schematic drawing of the Miller procedure for flatfoot: a — before surgery, b — after surgery.