Bunion or Hallux valgus
A bunion or hallux valgus is a prominence on the inner border of the foot effecting the big toe and at the level of the 1st metatarso-phalangeal (MTP) joint. The bunion prominence which is seen and felt on the inner border of the foot is not due to any growth of bone but is due to the 1st metatarsal bone. With a bunion this has become more prominent than normal because the 1st metatarsal has moved away from its immediate neighbour the 2nd metatarsal. This widens the forefoot thus producing the bunion.
An inevitability of the splaying of the foot which occurs with a bunion or hallux valgus is that the great toe itself is then pulled across in the opposite direction (towards the second toe) by the still normally located tendons of the big toe.
A bunion or hallux valgus is commonly confused with hallux interphalangeus (where the deformity lies more distally and which tends to be less problematic). Here there is no increase in the space between the metatarsals, and the deformity lies in the shape of the phalynx bone.
How does a bunion or hallux valgus occur?
A true bunion or hallux valgus results from a drifting inwards of the big toe metatarsal from its normal position closer to the second metatarsal. The bunion is the head of this first metatarsal which produces the prominence on the inner side of the now wider foot. Tendons run circumferentially around the metatarsal and toe. They both move and stabilise the toe under normal circumstances. In a bunion or hallux valgus, with the shift/displacement of the first metatarsal these tendons no longer lie in the correct axis and in fact act as a deforming force, contributing to the bunion condition.
Where will I get bunion or hallux valgus pain?
Where and why has bunion or hallux valgus pain occurred?
Bunions or hallux valgus tend to give pain predominantly from the metatarsal head on the inner border of the foot. The bunion tends to be painful mainly when in enclosed shoes and so is often more symptomatic in winter. As the front part of the foot splays and the great toe moves across towards the 2nd toe a bunion can also produce pain from the 2nd toe itself. The pain which a bunion produces on the 2nd toe is either due to direct rubbing between the great toe and the 2nd toe, a hammer toe type deformity produced due to crowding of the 2nd toe by the bunion and the 3rd toe.The hammer toe will either be painful from its top aspect where it rubs directly on shoe wear or its under surface in the area of the 2nd metatarsal head. This is made prominent and pushed to the sole of the foot by the 2nd toe rising upwards and driving the metatarsal head downwards.
It is unusual to have much bunion or hallux valgus pain when out of shoe wear or at rest. There are exceptions to this and in particular if symptoms have been ignored during the day and the bunion has become very painful during the day then some symptoms may be present at night. The pain from the region of the great toe at rest or at night is however more often a symptom of an arthritic big toe (hallux rigidus) rather than a straightforward bunion. To confuse matters these two conditions can sometimes coexist.
Bunion or hallux valgus pain is most often present when walking in enclosed shoes. There may be little bunion pain in sandals or barefoot. It is unusual to have much bunion pain when not putting weight on the foot or at night. If there is bunion pain at rest or at night then there may also be arthritic change within the toe.
Why do bunions or hallux valgus occur?
The causes of bunions are "multifactorial". In other words generally many things contribute to their occurence. Shoewear per se is a contributory factor but it isn't possible to say that the type of shoewear is necessairily relevant. Often there is a hereditary component with other family members also suffering with the same condition.
Do bunions or hallux valgus get worse?
The best thing to say about the natural history of bunions is that they are unpredictable. This is both in terms of whether the bunion deformity will progress, and also whether the bunion will become painful (if it is not already painful). It would probably however be true to say that once a previously painfree bunion has started to become painful it is not common for the bunion to go back to being entirely pain-free.
What treatments are available for a bunion or hallux valgus?
The choice of treatment for a bunion lies between non-operative (conservative) and operative treatment. Conservative treatment for a bunion means either wearing wider fitting shoes or shoes with softer leather or using some form of a spacer between the big toe and 2nd toe (or alternatively some form of splint to keep the great toe away from the 2nd toe). The spacers or splintage may apparently straighten the bunion but they make no difference to the width of the foot, and the splaying of the 1st and 2nd metatarsals which occur with a bunion deformity. Therefore this type of treatment will not improve the main pain in a bunion which occurs due to the width of the forefoot. An arch type support orthotic may be useful if a bunion is associated with a flatter foot. If you have a bunion this is however just one other thing to get into a shoe with an already wide foot.
If I have a bunion or hallux valgus, is the best treatment surgery?
The decision on bunion operative treatment is usually made on the basis of the level of pain and inconvenience caused by the bunion or second toe. There is no correct answer to the question, bunion pain and inconvenience are both highly subjective. An inability to get into a formal shoe may be a major problem for a business woman or man but no problem at all for someone wearing trainers every day. However in general if a bunion is free of pain then the recommendation would not be for surgery. That said, this is not an absolute. Once a patient has read this section and appreciated what surgery and the recovery entails the patient will be in a better position to discuss the possibility of bunion surgery for their symptoms.
Bunion or hallux valgus surgery – when and what?
If your bunion is symptomatic and causing you persisting and troublesome symptoms then surgery should be considered. There is no correct amount of pain or inconvenience which a bunion may cause which warrants surgery. Symptoms which a bunion causes are generally subjective, and what is a problem in one person’s view will not be a problem in another's.
For bunion surgery to be successful (correcting the deformity and losing the symptoms) the mechanical factors driving the deformity should be overcome. Bunion surgery should replace the 1st metatarsal closer to the 2nd thus reducing the width of the foot, and also realigning the tendons and reducing their deforming forces. These principals of bunion surgery are well demonstrated by the following x-rays which shows how a Scarf osteotomy has achieved this aim.