Foot and Ankle Reconstruction: From Bunions to Charcot Foot

The foot carries the entire weight of the body with every step. When its shape or alignment changes – through a birth deformity, injury, nerve disease, diabetes or arthritis – walking becomes painful, shoes stop fitting and the skin can break down. This article explains the common problems we treat and how reconstruction works.

How a healthy foot works

The foot is a flexible, arched structure of 26 bones that becomes rigid at push-off. Weight is shared between the heel, the outer border and the ball of the foot. The ankle, the subtalar joint below it and the joints of the midfoot work together so the foot adapts to uneven ground and then becomes a firm lever for walking. Problems arise when this balance is lost: weight concentrates on one area, the skin thickens, and pain or ulcers follow.

Understanding gait and weight-bearing

We examine how you stand and walk, which parts of the foot touch the ground, and how the knee and hip compensate. Many foot problems start higher up (a leg-length difference or knee deformity) or come from muscle imbalance after nerve damage or polio. Treating the foot without understanding the whole limb often leads to recurrence.

Common conditions

Hallux valgus (bunion). The big toe drifts towards the second toe and a painful bump forms. Mild cases improve with wide shoes and padding. Painful, progressive bunions are corrected by realigning the bone (osteotomy) and balancing the soft tissues; severe or arthritic cases may need joint fusion.

Lesser toe deformities and short toes. Hammer and claw toes are corrected with tendon and bone procedures. A congenitally short toe (brachymetatarsia) can be lengthened gradually with a small external fixator, or in one stage with a bone graft, depending on the length needed.

Flatfoot and high-arched foot (cavus). Painful flatfoot in adults often relates to a failing tibialis posterior tendon. High-arched feet are common after nerve conditions and polio. Treatment ranges from insoles and bracing to tendon transfers, bone realignment and, in rigid cases, fusion.

Diabetic foot. Diabetes can damage nerves (loss of protective sensation) and blood supply. Small injuries become ulcers, and ulcers can become infected and reach bone. Care is a team effort: blood-sugar control, offloading, wound care, treatment of infection and, where needed, removal of infected bone and correction of the deformity that caused the pressure.

Charcot foot (neuropathic arthropathy). In people with nerve damage, usually from diabetes, the bones and joints of the foot can weaken and collapse, often after a minor injury the person may not even feel. Early signs are a warm, swollen, red foot with little pain – easily mistaken for infection. Early immobilisation and offloading can prevent collapse. When the foot has already collapsed into a rocker-bottom shape with ulcers, reconstruction – often using an Ilizarov or circular frame, sometimes with internal fixation – can create a stable, plantigrade foot that can be fitted with a shoe or brace.

Post-traumatic and arthritic deformity. Malunited ankle and heel fractures, and arthritis of the ankle or hindfoot, are treated by realignment osteotomy, fusion or, in selected cases, joint replacement.

Neglected clubfoot and other complex deformities. See our dedicated article on adult complex clubfoot.

How we evaluate the foot

• Standing examination, footprint and gait observation
• Nerve and circulation check (essential in diabetes)
• Weight-bearing X-rays of the foot and ankle, and a hindfoot alignment view
• CT scan for complex bone deformity; MRI for tendons, infection or early Charcot changes
• Blood tests including HbA1c and markers of infection where relevant

Treatment options – from simple to complex

1. Footwear modification, custom insoles and braces
2. Offloading casts and walkers (especially for ulcers and early Charcot)
3. Tendon lengthening and tendon transfers to rebalance muscles
4. Osteotomy – cutting and realigning bone
5. Joint fusion (arthrodesis) for unstable or arthritic joints
6. Gradual correction with an Ilizarov or hexapod frame – useful when the skin is poor, the deformity is severe, or infection is present, because the foot can be corrected slowly without large incisions

Recovery

Foot surgery usually needs a period of protected or no weight-bearing, followed by gradual return to walking in a cast, boot or special shoe. Swelling can persist for months. In diabetes, lifelong foot care and appropriate footwear are part of treatment.

When to see a specialist urgently

• A red, hot, swollen foot in a person with diabetes
• An ulcer that is not healing, or any ulcer with discharge or a bad smell
• A foot that is changing shape