Cavus foot surgery: tendon transfers, osteotomies and fusion

When surgery is considered

For background on the condition, see cavus foot. Conservative treatment is always tried first: custom orthotics, footwear with a wider heel and a higher top, and bracing.^[4,1] Surgery is generally considered when:

• pain or instability continues despite those measures
• the ankle repeatedly sprains or gives way, or the peroneal tendons are irritated or torn (see chronic ankle instability and peroneal tendon injuries)
• weakness of the foot or ankle, or foot drop, needs to be compensated for
• the deformity is progressing^[4,3,1]

A nerve or muscle condition, if present, is evaluated first, because it decides how the deformity is likely to change.^[4,5]

The main types of operation

The goal is to correct the muscle imbalance and restore a stable, level foot that carries weight evenly on the heel, the outer edge and the ball of the big toe.^[1,5] The plan usually combines several parts:

• Soft-tissue release. Tight tissue on the sole of the foot, and sometimes tight tendons, are released so the foot can flatten and the bones can be lined up.^[2]
• Tendon transfers. A strong tendon is moved to take over for a weak one, so the muscles pull in balance. Gait examination helps plan which tendons to transfer.^[3,1]
• Osteotomies. Bones are cut and realigned to correct the tilt of the heel and the drop of the first metatarsal. The Coleman block test, done during the examination, helps decide whether the heel or the forefoot needs to be corrected.^[3,2]
• Fusion. In the most severe or stiff deformities, or when joints have worn out, one or more joints are fused.^[1,3] See foot and ankle joint fusion and replacement.
• Treating the consequences. Loose ankle ligaments, peroneal tendon problems and toe deformities are often treated in the same operation. See ankle ligament repair and reconstruction, peroneal tendon surgery and hammertoe surgery.

Because the deformities are complex, surgical plans need to be customized, and they usually involve a combination of soft-tissue and bone procedures.^[2] In progressive neuromuscular disease, the literature emphasizes early attention to tendon balance, because a deformity left to progress can become fixed and difficult to salvage.^[3]

Recovery

Recovery depends on how many procedures were done. A typical plan is a period in a splint or cast with limited or no weight on the foot, then a boot, then a gradual return to walking and physical therapy to restore strength and balance. Bone procedures and fusions need more time to heal than tendon procedures. Your surgeon will give you a timetable, and full recovery generally takes many months. Long-term follow-up and, in some people, ongoing bracing or orthotics help protect the result. See recovery after foot and ankle surgery and preparing for foot and ankle surgery.

Risks

Risks include infection, wound-healing problems, nerve irritation, stiffness, bones that are slow to heal or don’t unite, the deformity coming back, overcorrection, and the general risks of surgery, including blood clots. When a neuromuscular condition is present, the foot can change further over time, and some people need additional treatment later. The chance of these problems depends on the operation, the cause of the deformity and your health, including diabetes and smoking.

Questions to ask before deciding

• What is causing my high arch, and could it change over time?
• Which parts of the foot would you correct, and why?
• Will my ankle ligaments and peroneal tendons need treatment at the same time?
• How long will I be off my foot, and what braces or shoes will I need afterward?

When to seek care