Perhaps the most challenging of all foot deformities facing the surgeon today is hallux abducto valgus. It is not surprising that dozens of bunionectomy procedures have been developed during the last 100 years. These procedures are directed at the correction of deformities of the small first metatarsophalangeal joint. This joint supports 125% of the weight of a walking person during the propulsive phase of gait and must perform this function hundreds, if not thousands, of times a day, month after month, year after year.

The Reverdin-Isham bunionectomy procedure presented in this article has proven to be highly effective in a wide range of bunion deformities. The definition, cause, and classification of hallux abducto valgus, the Reverdin-Isham procedure with its preoperative criteria, the techniques of operation, postoperative management, the advantages and disadvantages, and the results of a 5-year blind study are presented.

Hallux Abducto Valgus is a combination of a transverse and frontal plane deformity of the hallux on the first metatarsophalangeal head. In this deformity, the hallux is laterally deviated toward the lesser digits and rotated with its dorsal surface more medially. Most bunion deformities— mild, moderate, or severe—contain some combination of these deformities. These deformities contain both soft-tissue and osseous components called positional and structural deformities.

The primary cause of hallux abducto valgus is the abnormal foot structure that, as dictated by genetic code, is exposed to abnormal pronatory forces resulting in hypermobility of the osseous structures and an overdependence on soft-tissue structures for stability during weight bearing and, in particular, during the last phase of the propulsive stage of gait. The severity of hallux abducto valgus is proportionate to the severity of the abnormal pronatory forces present.

Other causes of hallux abducto valgus deformities are systemic disease, such as gouty or rheumatoid arthritis, neurologic disorders, and trauma causing permanent osseous or soft-tissue damage to the first metatarsophalangeal joint.

The podiatric surgeon can expect the progression and severity of hallux abducto valgus to increase when more than one cause is present.

Footwear, although not a primary cause, can aggravate the symptoms of the deformity.