The foot is made up of many small bones that sit perfectly together forming many joints. The big toe joint comprises of the first metatarsal and the proximal (close) phalanx of the toe. A bunion forms when base of the toe (first metatarsal) drifts away from the second metatarsal. The 1st metatarsal rotates and drops and so no longer sits in its correct alignment. The tip of the first toe then rotates and drifts inwards. Overtime, under the continuing stress of this altered position of the joint and the irritation that this causes, the joint can become inflamed.
By far the most common cause of bunions is the prolonged wearing of poorly fitting shoes, usually shoes with a narrow, pointed toe box that squeezes the toes into an unnatural position. Bunions also may be caused by arthritis or polio. Heredity often plays a role in bunion formation. But these causes account for only a small percentage of bunions. A study by the American Orthopaedic Foot and Ankle Society found that 88 percent of women in the U.S. wear shoes that are too small and 55 percent have bunions. Not surprisingly, bunions are nine times more common in women than men.
Bunions starts as the big toe begins to deviate, developing a firm bump on the inside edge of the foot, at the base of the big toe. Initially, at this stage the bunion may not be painful. Later as the toes deviate more the bunion can become painful, there may be redness, some swelling, or pain at or near the joint. The pain is most commonly due to two things, it can be from the pressure of the footwear on the bunion or it can be due to an arthritis like pain from the pressure inside the joint. The motion of the joint may be restricted or painful. A hammer toe of the second toe is common with bunions. Corns and calluses can develop on the bunion, the big toe and the second toe due to the alterations in pressure from the footwear. The pressure from the great toe on the other toes can also cause corns to develop on the outside of the little toe or between the toes. The change in pressure on the toe may predispose to an ingrown nail.
Your family doctor or chiropodist /podiatrist can identify a bunion simply by examining your foot. During the exam, your big toe will be moved up and down to determine if your range of motion is limited. You will be examined for signs of redness or swelling and be questioned about your history of pain. A foot x-ray can show an abnormal angle between the big toe and the foot. In some cases, arthritis may also be seen. A X-ray of your foot may help identify the cause of the bunion and rate its severity.
Non Surgical Treatment
Initial treatment of bunions may include wearing comfortable, well-fitting footwear (particularly shoes that conform to the shape of the foot and do not cause pressure areas) or the use of splints and orthotics (special shoe inserts shaped to your feet) to reposition the big toe. For bunions caused by arthritis, medications may help reduce pain and swelling. If nonsurgical treatment fails, your doctor may suggest surgery, which resolves the problem in nearly all persons. The goal of surgery is to relieve pain and correct as much deformity as possible. The surgery is not cosmetic and is not meant to improve the appearance of the foot. Other related procedures that may be used to help diagnose foot disorders include X-rays of the bone and foot.
In 2010, the National Institute for Health and Care Excellence (NICE) published guidance about a minimally invasive surgical procedure to treat bunions. The aim of the procedure is to repair the tilting of the big toe. The technique can be carried out under a local anaesthetic or a general anaesthetic, using X-rays or an endoscope for guidance. The type of endoscope used will be a long, thin, rigid tube with a light source and video camera at one end. One or more incisions will be made near the big toe so that bone-cutting instruments can be inserted. These will be used to remove the bunion and to divide one or more bones located at the front of the foot. Wires, screws or plates will be used to keep the divided bones in place. After the procedure, you may need to wear a plaster cast or dressing to keep your foot in the correct position until the bones have healed. You may be given a special surgical shoe that enables you to walk on your heel. As the procedure is relatively new, there's little in the way of reliable evidence regarding its safety or effectiveness.
If the diagnosis is made early on, such as in preadolescence, bunion development can be slowed and in some cases arrested with the proper supportive shoe gear and custom functional shoe inserts (orthotics). Avoidance of certain athletic activities with improper shoe fit and toe pressure can prevent the symptoms that occur with bunions.