Hallux valgus: Definition, causes, evolutions and complications

Hallux valgus is the most common pathology of the foot. Why is it formed? What are the possible developments and complications?

Dr. Lopez, who has been an expert in hallux valgus surgery for several years, explains in detail everything you need to know about hallux valgus before your procedure.

What is hallux valgus of the foot?

Hallux valgus of the foot (or bunion) is an outward deflection of the big toe. This deviation causes the bone called the "first metatarsal" to move inward in the foot. All of these movements will cause a lump on the inner edge of the forefoot. This bump is in fact the joint between the metatarsal and the first phalanx of the big toe which has become very prominent due to the various deviations. It is this lump that is called hallux valgus or "bunion."

The bump may appear on one foot or on both feet at the same time. In the latter case, we speak of bilateral deformation. Hallux valgus are often more troublesome and more painful.

Hallux valgus bunion

The different stages of hallux valgus

  • Mild hallux valgus: mild hallux valgus corresponds to a deviation of the big toe of less than 20°. At this stage, the phalanx of the big toe and the metatarsal are still properly fitted.
  • Moderate hallux valgus: when we talk about moderate hallux valgus, we mean a deviation between 20° and 40°. At this point, the phalanx is no longer in the same axis as the metatarsus and the two no longer fit together properly. The big toe will then come into conflict with the 2nd toe.
  • Severe hallux valgus (or bunion): this type of hallux valgus corresponds to a deviation greater than 40°. Here the big toe goes above or below the 2nd toe.

The factors behind the bunion of the foot

There are several factors that can cause bunions on the foot.

A genetic predisposition

You are more likely to suffer from hallux valgus as an adult if one of your parents already has this condition.

An anatomical deformation

Anatomy is one of the factors that has a significant influence on the onset of hallux valgus. Among the possible deformities we can cite: flat feet, the orientation and anatomy of the facet joints between the 1st metatarsal and its 1st phalanx, or a muscular cause.

Gender, weight and age

Whether you are a man or a woman, the predisposing factors for hallux valgus are not the same. In women, footwear and a low Body Mass Index can promote the development of hallux valgus. In men, a high BMI and a flat foot favor the development of a foot valgus.


Some shoes force the foot to bend to fit inside. Narrow, pointed and high-heeled shoes have a real impact on the development of hallux valgus.

The shape of the foot

There are 3 main forms of feet.

  • “Greek feet”: when the 2nd toe is longer than the 1st.
  • The "Egyptian feet": which have a decreasing size of the toes.
  • The "square feet": characterized by an identical length of the first two toes.

People with "Egyptian feet" are more predisposed to hallux valgus because the longer toe is more exposed to stress.

Hallux valgus pain, changes and complications

For hallux valgus pain, it may be completely painless. However, it is essential to act quickly in order to limit possible complications and the appearance of other pathologies. Hallux valgus-related foot problems are numerous.

Possible developments and complications of hallux valgus

  • The deformed and protruding area called the “bunion” rubs against the shoe, which can cause the development of calluses (hard thickenings of the skin).
  • Rubbing can also create bursitis, which is the inflammation of the lining of the metatarsophalangeal joint. The hallux valgus then becomes red, hot, and painful. It is then complicated to put on shoes.
  • Over time, the foot deformity and hallux valgus worsen and become more prominent. This can cause a transfer of pressure to the other toes. The bursitis then enlarges and causes a deformation of the entire foot.
Hallux valgus pain

In particular, calluses are found on the sole of the foot and corns on the lateral toes. The deviation of the big toe drives out the lateral toes which curl up and form "claws".

In the event of little painful hallux valgus, it can be tempting to leave it lying around and not treat the condition. Yet it is important to act quickly and prematurely. Over time, the initial pain may go away. This is not necessarily a good sign and very often indicates a rupture of the joint capsule.

Possible treatments

There really isn't a nonsurgical treatment for hallux valgus. The only way to really get rid of it is to have surgery. Dr. Lopez has all the knowledge and expertise to help you before, during and after your procedure. Thanks to minimally invasive surgery, complications and post-operative pain will be reduced.