The bunion or hallux valgus is the main deformation observed in the forefoot. This is a deviation of the big toe going outward.
Inflammation, or redness of the joint of the big toe, is the first painful manifestation, called bursitis.
Hallux valgus is thus the most common deformation encountered at the level of the feet:
The first metatarsal bone, the long bone upstream of the big toe is moved inwardly (varus), and the big toe (hallux) outwardly (valgus).
In a schematic way, the first metatarsal leaves inwards, which weakens the joint capsule of the big toe internally. The extensor tendon of the big toe, the one that raises the big toe upwards, will have a “Bowstring effect” by twisting. This will bring the big toe outward. This means that once formed, the deformation can stabilize at best, but cannot improve spontaneously.
The exostosis (or bony bulge), located at the inner edge of the foot (and being the top of the deformation angle), or “bunion” is born and aggravated by conflict with the shoe (bursitis). This exostosis is born from the absence of good joint congruence, which generates bone growth instead.
First stage or (hallux valgus beginning).
Pain (only with shoes wearing) appears either around the age of 15-20 in the case of congenital hallux valgus (33%), or around the age of 40-50 in degenerative hallux valgus cases.
It manifests itself, at first, on the exostosis, with contact with fine shoes or after a prolonged walk. It is a simple inflammation (hot, red, swollen, painful appearance) with sometimes a bursitis (collection filled with liquid) which can become infected. This first stage can be very painful even in case of minimal deformation. Conversely, a major deformation may not hurt.
The X-ray shows that this exostosis is located at the top of the angle formed by the big toe offset outside and its metatarsal offset inside.
Each step will therefore produce an effect of «bowstring» (due to the extensor tendon of the big toe) that makes the deformation irreversible until the metatarsal has been straightened, which can only be done by surgery.
Second stage of the hallux valgus:
Two possible evolutions:
- Painful outbreaks follow and increase in intensity leading to the intervention.
- Flare-ups are fading and there is a lull that can last several years.
This lull period is misleading because deformation, in general, continues to evolve, even slowly. This results in deformations of the other toes starting with the 2nd toe.
This allows the big toe to pass under or above this second toe. This results in support disorders with callus build-up, and displacement of pain. This pain under the second toe can then mask the pain associated with the big toe.
The natural evolution of the deformation is therefore the constitution of claw toes (hammer shape). These claws over time will become irreducible, with surgical necessity, thus complexifying down the operative action. The irreducibility is characterized by the fact that by pulling on it, we cannot put back the right toe.
Then there is a difficulty with the shoes’s wearing. When the wardrobe is renewed, it will be necessary to choose shoes with rounded toe boots in winter, and sandals with «rigid soles» in summer. We’ll lower the heels, and we’ll choose stiff shoes underneath, and soft shoes above.
Pre-operative x-rays are essential to study the lateral toes, to evaluate the harmony of the forefoot’s arch. These make it possible to anticipate a possible transfer of post-chirurgical load that could lead to pain. Finally, they make it possible to choose the surgical procedure most suited to the patient.