Joint, Ligament and Muscle Disorders

Bunions

Anatomy

Nearly one-fourth of all bones in the human body are in the feet. The foot is a complex, flexible structure that contains bones, joints, and more than 100 muscles, tendons and ligaments, all working together to enable movement and balance. The foot is divided into three sections, the forefoot, midfoot and hindfoot. The forefoot has five toes (14 phalanges) and five longer bones (metatarsals). One phalanx of each of the five toes connects to one of the five metatarsals.

The big toe, or great toe (hallux), is made up of two joints. The metatarsophalangeal joint (MTP) is the largest of these, and the closest to the base of the toe, where the first long bone of the foot (metatarsal) meets the first bone of the toe (phalanx). In the MTP joint, as in any joint, the ends of the bones, where they touch, are covered by articular cartilage, a smooth substance that protects the bones and enables them to move easily.

Description

A bunion is a bump on the MTP joint, on the inner border of the foot. Bunions are made of bone and soft tissue, covered by skin that may be red and tender.

Symptoms

A bunion may be sore and swollen. If you have a bunion, it may hurt to wear any type of shoe. The MTP joint flexes with each step, so as the bunion becomes larger, walking becomes increasingly painful and bursitis may also set in. A bunion may cause the big toe to angle toward the second toe, or possibly move all the way under it. Pressure from the big toe may force the second toe out of alignment, sometimes causing it to overlap the third toe. Skin on the bottom of the foot may thicken and become painful. An advanced bunion can make the foot look grotesque and if it becomes too severe, walking may be difficult. Pain may become chronic and you may develop arthritis.

Causes

Prolonged wearing of poorly fitting shoes is by far the most common cause of bunions, especially styles that feature a narrow, pointed toe box that squeezes the toes into an unnatural position. Bunions also have a strong genetic component, and they can develop as a result of hallux valgus, a foot deformity. "Hallux valgus" is a Latin term that means a turning outward (valgus) of the big toe (hallux).

Nonsurgical Treatment

Prevention is best, so minimize your chances of developing a bunion by never forcing your feet into shoes that fit improperly, are short, tight, sharply pointed, or have heels higher than 2 1/4 inches. Instead, choose shoes with wide insteps, broad toes and soft soles that conform to the natural shape of the feet.

If you already have a bunion and it is not too severe, it may be treatable without surgery. Wearing shoes that are roomy enough to not put pressure on the bunion should help relieve pain. Protective pads can be used to cushion the painful area, and you may also want to consider having your shoes stretched professionally. If the bunion causes difficulty walking or produces pain despite wearing accommodating shoes, you may need surgery.

Surgery

Orthopaedic surgeons use various surgical procedures to treat bunions, but the common goal for them all is to realign the joint, relieve pain, and correct deformity. Your orthopaedic surgeon will choose the procedure that is best suited to your condition.

• Repair tendons and ligaments around the big toe—Tendons and ligaments may be too tight on one side and too loose on the other, creating an imbalance that causes the big toe to drift toward the others. Often combined with an osteotomy (see below), this procedure restores balance by shortening loose tissues and lengthening those that are tight.
• Arthrodesis—Damaged joint surfaces are removed, and screws, wires or plates are inserted to hold surfaces together during the healing process. This is typically used for patients with severe bunions, severe arthritis, and when other procedures have failed.
• Exostectomy—The bump on the toe joint is removed. Appropriate only for an enlargement of the bone with no drifting of the big toe, this procedure is seldom used because it rarely corrects the cause of the bunion.
• Resection arthroplasty—The damaged portion of the joint is removed. This procedure creates a flexible "scar" joint. It is used mainly for patients who are older, have had previous bunion surgery, or have severe arthritis.
• Osteotomy—This is the surgical cutting and realignment of the joint.

With any surgery there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. Your orthopaedic surgeon will speak to you prior to surgery to explain any potential risks and complications that may be associated with your procedure.