Congenital cavus foot

　　The etiology of high-arched feet is still unclear. Research has found that the main causes of this disease may include the following several types:

　　1. Bentzon believed that the cause was weakness of the tibialis anterior muscle, while the peroneal muscle was strong, pulling the first metatarsal bone to make the foot pronate. To compensate for the function of the tibialis anterior muscle, the extensor muscles contract, causing the metatarsophalangeal joints to extend, and then the flexor muscles contract, causing the interphalangeal joints to flex. Some scholars believe that the imbalance between the strong peroneal muscle and the weak tibialis anterior muscle leads to the occurrence of high-arched feet, but most patients with high-arched feet in clinical practice do not have the phenomenon of tibialis anterior muscle atrophy.

　　2. Duchenne believed that the loss of function of the intrinsic muscles of the foot (interosseous muscles and lumbricals) led to contracture of the extensor and flexor muscles, resulting in claw toe deformity. It is most common in patients with poliomyelitis, where both the intrinsic and extrinsic muscles are initially paralyzed, and then the extrinsic muscles gradually recover, while the intrinsic muscles atrophy and fibrotize. Although the支配function of the nerves is restored, the intrinsic muscles lose function due to contracture, leading to the formation of high-arched feet.

　　3. When the gastrocnemius muscle is paralyzed, the function is compensated by the flexor muscles of the sole of the foot when walking, causing the interphalangeal joints to flex and the anterior foot to drop, forming a high-arched foot.

　　4. Muscles may become fibrotic and contractile due to certain reasons, which can also lead to claw toe deformity.

　　5. Some high-arched feet of unknown cause often have a family history of disease, so it is believed that genetic factors are involved in the pathogenesis, but there is a lack of genetic evidence.

　　In summary, the etiology of high-arched feet is still unclear. Some cases of anterior foot drop are primary deformities, sometimes claw toes occur first, and occasionally there are cases of concurrent foot inversion. Therefore, each patient should be examined in detail to understand the cause of the disease.

　　The skin on the head of the metatarsal bone on the sole of patients with congenital high-arched feet may form calluses,Occasionally, there may be foot inversion.. “Calluses” are commonly known as “foot pads”, which are abnormal hardening and thickening of the skin, also known as corns. It is a local hyperkeratosis of the skin on the hands and feet caused by long-term compression and friction.

　　Patients with congenital high-arched feet may show symptoms and signs of varying degrees of severity due to the different degrees of deformity:

　　1. The typical deformity is characterized by a high longitudinal arch of the foot and a shortened foot length. The metatarsophalangeal joint can be seen in extension, and the interphalangeal joints in plantar flexion. The skin on the head of the metatarsal bone on the sole may form calluses, and even necrosis may occur.Occasionally, claw toes may occur..

　　2. Most patients cannot walk for a long time, the feet are easily tired, and there is a feeling of soreness.

　　3. The foot has no elasticity, and the ankle dorsiflexion is limited.

　　4. The area of contact between the sole of the foot and the ground decreases. However, in cases with mild deformity, the deformity may be reduced or even disappear when standing and bearing weight, and the footprint will show a normal shape.

　　The etiology of this disease is complex, therefore, it is extremely difficult to prevent. The diagnosis of this disease should focus on identifying the cause, distinguishing whether it is secondary or primary, in order to adopt the correct treatment. After children develop some neuromuscular diseases, it is important to actively check and prevent the occurrence of this disease.

　　The X-ray manifestations of patients with congenital high-arch feet show that the X-ray lateral view of the foot when standing is taken, and the high-arch foot deformity is most typical. The joint surfaces at the anterior and posterior ends of the first cuneiform bone of the normal foot are almost parallel. In the case of high-arch feet, because the apex of the forefoot drop is mostly located on the first cuneiform bone, the bone is wide at the top and narrow at the bottom, and the joint surfaces at the anterior and posterior ends lose parallelism, forming an angle towards the plantar surface. In rare cases, the apex of the forefoot drop is located on the navicular bone, and there is often a hard bony prominence on the back of the foot. Secondly, the axis of the talus bone and the first metatarsal bone of the normal foot are on a straight line, while in high-arch feet, they form an angle.

　　Patients with congenital high-arch feet should have a light diet, eat more vegetables, nuts, seeds, grains, and other beneficial foods, and pay attention to a reasonable diet. Avoid smoking, alcohol, spicy, and fried and roasted foods. Avoid excessive drinking. Because excessive alcohol consumption can cause significant liver damage, reduce the body's immunity, and have a serious impact on disease recovery.

　　The treatment goal of congenital high-arch feet in Western medicine is to alleviate symptoms, improve foot walking function, correct and prevent the progression of deformities. For those with mild deformities and good foot elasticity, the high-arch deformity can be reduced or disappear when standing and bearing weight, and low-heel orthopedic shoes can be worn, with metatarsal pads for those with calluses. For moderate and severe deformities, surgical treatment is required.

　　1. Plantar Fasciotomy:Applicable to spastic high-arch feet and can be performed after the age of 1. Generally, the anterior aspect of the medial malleolus is chosen, and the plantar fascia is cut at the most tense point when the forefoot is extended. The postoperative cast is fixed for 4 to 6 weeks.

　　2. Long Extensor Tendon Transfer Surgery:Applicable to paralytic high-arch feet. The method is to move the insertion point of the long extensor muscle posteriorly to the back of the first metatarsal bone, making it a dynamic tendinous structure to prevent the forefoot from dropping. If necessary, the extensor digitorum muscle tendons can also be moved posteriorly, and the contracted soft tissues on the sole can be released. The postoperative cast is fixed for 3 months.

　　3. Tarsometatarsal Joint Osteotomy and Triple Arthrodesis:Applicable to larger children or adult patients with obvious deformities.