Hallux abducto valgus is a deformity involving the first metatarsal phalangeal joint or big toe joint that leads to the displacement of the first metatarsal bone causing a prominent ‘bump’ or bunion deformity and a deviation of the big toe toward the second toe.
The deformity is found in approximately 9 percent of the adult United States population and appears to be more prevalent in women. The underlying cause appears to be linked to genetic factors, which influence the development of joint structure that influence foot motion. Abnormal foot pronation or fallen arches is theorized to be a cause of the development of bunion deformities by changing the normal mechanics of the big toe joint. Shoes have been shown to play an influence also by placing abnormal pressure on the first toe.
Symptoms can very depending on the size of the bunion, types of shoes worn and levels of activity. Generally pain develops at the ‘bump’ site from shoe pressure. Occasionally pressure from the shoe against the metatarsal ‘bump’ can cause an injury to a nerve causing sharp pain over the ‘bump’ and even numbness to the first toe. Aching of the big toe joint from abnormal joint stress placed on the soft tissues surrounding the bunion is also a common complaint.
Conservative treatment is primarily directed at decreasing the shoe pressure against the bunion by making shoe gear changes as well as by controlling the abnormal foot pronation with the use of orthotic devices. Lace style shoes with a wide toe box should typically be used while Loafer, flats or heels should be avoided because by design these shoes are always narrower through the front of the foot. In addition to shoe gear changes occasionally using an orthotic device within the shoe can restore more normal joint motion thus decreasing the achy quality pain that can occur. Other treatments are more supportive but can include the use of padding on the foot as well as the use of anti-inflammatory medications.
If conservative measures fail to decrease pain surgical correction may be considered. Surgical correction must be individualized for each patient and is based upon a thorough clinical exam and x-ray evaluation. X-rays should be taken while putting weight on the foot to determine the true severity of the bunion deformity. The main goal of surgery is to decrease pain by restoring the joint to normal position. This typically involves the surgical release of tight soft tissues surrounding the joint as well as cutting the metatarsal bone to reposition it. The surgical procedure is usually performed in a surgicenter with a local anesthetic and ‘light sedation’ administered by an anesthesiologist. Recovery varies depending on the procedure performed.
For patients with a more severe bunion deformity post operative recovery often involves the use of crutches for a non weight bearing period of four to six weeks. With less severe bunion deformities a post-operative shoe or removable walking brace is used after surgery for a period of three to four weeks. Aggressive early post operative range of motion exercises are performed to restore normal joint motion. Post-operative care may include the use of customized orthotic devices to help restore more normal foot mechanics. This measure as well as the use of adequate shoe gear will help optimize long term surgical results.