Bunions and Hallux Abducto Valgus (HAV) refer to the bony lump found at first metatarsal phalangeal joint (base of the first toe). Bunions are a progressive condition and in most cases will become painful at some stage depending on the severity of the bunion and the amount of activity of the individual.
There are a number of factors to consider in determining the cause of a bunion which are:
- Biomechanical position of the foot – is the foot position responsible for the bunion?
- Genetics – do mum, dad or grandparents have bunions?
- Footwear – is the footwear shape or instability causing the bunion?
- Activity level – is the activity level too great for this particular foot type?
Usually a bunion forms due to a combination of the above causes with the most common factor being a biomechanical abnormality of the foot causing excessive pronation (rolling in). When the foot over pronates (rolls in) the entire foot everts (twists to the centre). This causes the first-metatarsal-phalangeal joint (MPJ) to twist as the big toe is fixed and planted securely on the ground and the foot in moving inwards. As the foot moves on to the toes for propulsion the 1st mp joint is effectively cross threaded as the first toe tries to extend.
It is this cross threading that causes irritation of the bone and surrounding joint. When bone is irritated it will grow in order to protect its structure. As the joint is irritated the bony growths form on the areas of greatest cross threading. This in turn causes greater irritation as the joint will now jam on the excess bone formation. And the cycle repeats with joint jamming, bone formation which causes greater joint jamming and so on. When this poor mechanical position is coupled with ligamentous laxity (flexibility), high activity, a genetic predisposition for bunions or poor fitting footwear, the bunion is likely to form and cause significant debility.
Treatment for bunions can be handled conservatively (no surgery) or by surgery. Conservative treatment involves correcting the underlying biomechanical factors such as excess pronation. This can be achieved by using a foot orthosis.
The results of the conservative treatment will relieve the discomfort associated with bunions and slow their deformity, however they will not make the first toe straight again. If this is the desired result then surgery is the only option. Bunion surgery will be the most effective way to straighten the toe. Bunion surgery however should not be taken lightly as there will be a lengthy recovery period and considerable discomfort. It is advisable you seek opinion from you podiatrist or surgical podiatrist regarding these options.