Bunions are one of the most common foot disorders seen in podiatry. A bunion is a “bony lump” found near the base of the big toe, which is usually an adaptation of the positional change of the big toe. Hallux abducto valgus (HAV) is a medical term, which describes the position of the hallux (big toe) with respect to the connecting bone of the mid foot (metatarsal). In this foot disorder, the hallux moves towards the second toe and the metatarsal shaft moves towards the middle of the foot.
- Foot type
- Hereditary factors
- Footwear habits
- Biomechanical factors (pronation)
- Neuromuscular dysfunction
- Ligament Dysfunction (laxity)
With the positional change of the hallux, pain is a common occurrence. As the foot goes through the gait cycle, the hallux plays an integral role as the body’s weight transmits through it during propulsion. The big toe is the rigid lever that supports toe off. Mechanically the change in the hallus joint would cause joint narrowing and early degeneration of the articular cartilage. In addition, two small bones (sesamoids) found underneath just behind the joint will start placing extra pressure on the metatarsal. Along with bony changes, there are additional soft tissue changes as the hallux and metatarsal reposition. This causes added strain to other bony structures and can accelerate the problem.
It is important to understand what is causing the abnormality, and at what level the degeneration has reached. HAV has four significant stages which may take many years to progress from one stage to another and each stage gives an indication to what level of degeneration is present. A comprehensive history is required, along with establishing what may be causing HAV and be possibly accelerating it. Depending on the stage of the deformity, it is imperative to determine the degree of mobility available to the patient with such a deformity.
There are two ways to treat this pathological foot condition, conservatively or surgically. Conservative treatment is the first line of treatment. Orthotic care can be used to reduce the causative factors. Realigning the foot with the aid of an orthotic helps prevent further degeneration and / or reduce symptoms of HAV in any stage of its deformity. Along with orthotic care, patients may require conservative debridement of corns and calluses produced due to extra forces on the foot. Orthotics will also help the function of the big toe joint as it allows it to bend in the correct position.
Footwear advice is essential in the conservative care of HAV. There may be a need to change footwear to accomodate the orthotic as well as the bunion. Surgical correction of HAV is an option, however should only be considered when conservative care has failed to reduce the onset of HAV. It is only considered if there is a clear sign that it will improve the quality of life for the patient.