Hallux valgus (crooked toe)

Hallux valgus is an anatomical malposition of the big toe. This results in a crooked position of the big toe, whereby it is bent towards the outside of the foot from the base of the big toe joint. This misalignment favors the development of pressure points as well as painful inflammations in the joint, which can be caused by the pressure of the shoe shaft on the foot.

Women are primarily affected by hallux valgus. The deformity develops over the course of several years, with the incidence increasing with age.

The main cause is the use of the wrong footwear. Wearing high-heeled and pointed shoes imposes an unnatural posture on the foot, which can lead to the development of deformities over time. Hallux valgus is particularly widespread in countries with western-style footwear. A comparison with countries in which women wear no shoes or only flat and open shoes shows that hallux valgus occurs much less frequently in these regions.

Hallux valgus is often the result of western shoe fashion, which promotes the development of foot malpositions due to the unnatural foot position (for example with high-heeled or pointed shoes).

In the case of splayfoot, the sinking of the front transverse arch of the foot leads to a widening of the ball of the foot and thus to a crooked position of the big toes. Splayfoot is mainly caused by congenital weak ligaments and weak connective tissue as well as by insufficient training of the inner foot muscles due to infrequent barefoot walking. In the case of a congenital splayfoot, the development of a hallux valgus is also strongly promoted by unsuitable footwear with only little space in the front area of the foot.

The anatomical malpositioning of the foot also leads to changes in the direction in which the tendons are pulled, which impairs their function. This means, for example, that it is no longer possible to spread the big toe.

In most cases, hallux valgus causes little discomfort. The deformity is considered more of a cosmetic problem by those affected. If there is any discomfort, it usually occurs at the metatarsophalangeal joint of the big toe. With hallux valgus, the first metatarsal bone protrudes prominently here, giving the foot additional width at its widest point. As a result, the skin at this point can become very irritated mechanically if the shoes are too narrow, which leads to pressure points and subsequently to inflammation.

If the inflammation persists, the protective bursa of the metatarsophalangeal joint of the big toe will enlarge over time, causing the foot to become even wider at this point and further increasing the pressure caused by shoes that are too narrow. This leads to a cycle of pressure points, swelling, inflammation and pain.

The metatarsophalangeal joint of the big toe can develop arthrosis (wear and tear of the joint beyond the normal age). In very severe cases, the foot can become so deformed that the big toe overlaps the second and third toes. This severe deformation prevents the foot from walking naturally and results in pressure points and pain on the foot.

Due to the easily recognizable malposition of the big toes and the characteristic complaints, a hallux valgus can usually be confirmed by the doctor as a visual diagnosis. For further clarification, an X-ray of both feet is taken while standing. In this way, other foot malpositions such as splayfoot or arthrosis of the metatarsophalangeal joint of the big toe can be detected.

Since it is practically impossible to reverse a foot malposition once it has been established in adulthood, in the case of severe complaints an improvement can often only be achieved by surgical correction. Shoe inserts, splints and bandages can partially contribute to a reduction in pain, but the foot deformity cannot be corrected.

There are about 150 different surgical methods for correcting hallux valgus, of which about 10 are commonly used in German-speaking countries. Most operations are performed on an outpatient basis under local anesthesia. The surgeon makes a small incision in the skin of the big toe and tries to restore the original joint conditions as far as possible. Which surgical method is used depends primarily on factors such as the degree of foot deformity as well as the extent of the arthritis. The following methods are frequently used:

• If there is only a small angle of bend between the first and second toes and no severe osteoarthritis, the surgical procedure first involves cutting through the first metatarsal bone slightly below the metatarsophalangeal joint of the big toe. Then, a small piece of bone is removed and the toe-side portion of the metatarsal is pushed back into its original position at the second metatarsal. The bones are fixed with wires or screws if necessary, and the big toe is straightened with sturdy sutures. The toe muscles are tightened again by relocating the tendons. This procedure can correct the majority of foot deformities caused by hallux valgus.

• If there is a severe angle of bend between the first and second toes and there is no severe arthritis, the metatarsal bone is not cut below the metatarsophalangeal joint of the big toe, but at the base of the bone and straightened. Sometimes it is necessary for the bone to be additionally cut just below the metatarsophalangeal joint of the big toe and straightened.

• In cases of severe osteoarthritis, not only must the angle of the big toe be straightened, but the wear and tear on the joint must also be treated. To do this, a piece of the metatarsophalangeal joint of the big toe as well as the bony prominence on the medial side of the metatarsal bone are removed, the bones are brought into the correct position and straightened with wire pins. The disadvantage of this method is that it shortens the big toe, which some patients find visually disturbing. Depending on the degree of arthrosis, it may be advisable to perform an arthrodesis - in which the metatarsophalangeal joint of the big toe is fixed with plates or screws. This method achieves good long-term results and it is extremely rare for hallux valgus to recur. Although the joint is stiffened by the fixation, this does not lead to any impairment when walking.

In the period after the operation, a relief shoe must be worn for at least three to four weeks. This is a special shoe in which the foot cannot roll, which ensures that the foot is protected. In some cases, immobilization in a plaster cast is necessary. After this time, normal, comfortable shoes with special insoles can be worn again. After the surgical treatment, professional physiotherapy (physical therapy) should be carried out for about six weeks to improve healing and strengthen the inner muscles of the foot. Sporting activities and long distances on foot should be avoided for the first three months after the operation.

The long-term prognosis for the surgical treatment of hallux valgus is extremely good. As with any operation, there is a risk of bleeding, infection, damage to nerves or thrombosis. Rarely, the big toe may be shortened after surgery and the function of the metatarsophalangeal joint of the big toe may be impaired. If the same unsuitable footwear is worn again after the surgical correction and the training of the foot muscles is neglected, a hallux valgus may develop again.

As long as the hallux valgus has not yet led to severe arthrosis of the metatarsophalangeal joint of the big toe, the results after surgery are usually very good and patients live free of complaints. In the period directly after the operation, a supporting splint should be worn at night. From now on, regular barefoot walking, training of the inner foot muscles through certain exercises and wide, healthy shoes should be observed.

Since hallux valgus is usually caused by wearing shoes that are too tight, high-heeled or pointed, the foot deformity can be effectively prevented by paying attention to your footwear. The shoes should also be changed more often in order to stress and strengthen the foot muscles in different ways. In addition, the risk of developing hallux valgus can be greatly reduced by regularly walking barefoot, hiking on uneven terrain and doing exercises to strengthen the inner muscles of the foot. If the orthopaedist prescribes insoles, they should be worn daily.