JaniceDickowのブログ

Overview

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.

Causes
Long periods of pressure from a tight-fitting shoe can cause the inflammation and the pain. This often happens when the big toe is forced into a position where it presses inward and overlaps the second toe. The base of the big toe then is pushed beyond normal alignment of the foot, resulting in the prominence typical of a bunion.
SymptomsBunions may or may not cause symptoms. A frequent symptom is foot pain in the involved area when walking or wearing shoes that is relieved by resting. A bunion causes enlargement of the base of the big toe and is usually associated with positioning of the big toe toward the smaller toes. This leads to intermittent or chronic pain at the base of the big toe. Bunions that cause marked pain are often associated with swelling of the soft tissues, redness, and local tenderness. It is important to note that, in post-pubertal men and post-menopausal women, pain at the base of the big toe can be caused by gout and gouty arthritis that is similar to the pain caused by bunions.

Diagnosis
Bunions are readily apparent - the prominence is visible at the base of the big toe or side of the foot. However, to fully evaluate the condition, the foot and ankle surgeon may take x-rays to determine the degree of the deformity and assess the changes that have occurred. Because bunions are progressive, they don?t go away, and will usually get worse over time. But not all cases are alike - some bunions progress more rapidly than others. Once your surgeon has evaluated your bunion, a treatment plan can be developed that is suited to your needs.

Non Surgical Treatment
Long-term treatment of bunions must be directed towards re-balancing the foot, so that we no longer walk with our weight forced on to the inner border of the foot. This is accomplished by controlling and reducing pronation with the use of a high quality arch support or custom made orthotics. These devices comfortably re-balance the feet and overcome pronation. This reduces the abnormal weight forces on the big toe and its metatarsal head, allowing the feet to function normally. As a result, the deformity should not worsen, and the pain should gradually subside. If the foot is not re-balanced, the deformity and pain will become worse.


Surgical Treatment
There are many different surgical procedures that can be performed. The decision to perform one type of surgery or another is based upon the extent and magnitude of the bunion deformity, the presence of arthritis in the big toe joint, and the space between the first and second metatarsals, which is called the intermetatarsal angle. It is very rare that a bunion can be treated by simply shaving down the bump of the bone. Invariably, the deformity will recur and both the bunion and the hallux valgus will return. Therefore, the shaving of the bunion, called an exostectomy, is performed in conjunction with a cut of the first metatarsal bone (which is called an osteotomy).

Prevention
The best way to reduce your chances of developing bunions is to wear shoes that fit properly. Shoes that are too tight or have high heels can force your toes together. Bunions are rare in populations that don?t wear shoes. Make sure your shoes are the correct size and that there's enough room to move your toes freely. It's best to avoid wearing shoes with high heels or pointy toes.