Avascular necrosis of the foot and ankle

What happens

Bone is living tissue with its own blood supply. When that supply is interrupted, parts of the bone die and can gradually collapse, damaging the joint surface and eventually causing arthritis. The talus is vulnerable because much of it is covered in cartilage, leaving little room for blood vessels, which is why a displaced fracture of the talus carries a particular risk of AVN.^[1]

Other bones in the foot can be affected too, including the navicular in the midfoot and the heads of the metatarsals.

Symptoms

AVN can be silent early on. As it progresses it causes deep, aching ankle or foot pain, worse with standing and walking, swelling, stiffness and, later, the grinding and deformity of arthritis.

How we evaluate it

We review your history, especially any past injury, steroid use and medical conditions, and examine the foot and ankle. X-rays at the practice show later changes such as increased density or collapse; MRI detects AVN earlier and shows how much bone is involved, which guides treatment.^[1]

Treatment

Early stages. Protecting the bone is the priority: a period of limited or protected weight-bearing in a boot or brace, while the blood supply recovers. A systematic review found that prolonged protected weight-bearing gave the most favorable outcomes in early talar AVN, possibly combined with shockwave therapy.^[2] See shockwave therapy.

If symptoms persist or the bone is at risk of collapse, surgical options include:

• Core decompression, drilling into the affected bone to relieve pressure and encourage new blood vessels to grow in.^[2,1]
• Bone grafting, sometimes with a graft that brings its own blood supply.^[1]
• Biologic adjuncts such as bone marrow aspirate concentrate, prepared in the operating room, used alongside other procedures; clinical evidence in the foot and ankle is still limited.^[3]
• Fusion of the affected joints for advanced collapse, which relieves pain by stopping motion.^[2]
• Total talus replacement with a custom implant made from your CT scan, a newer option for selected patients whose evidence is still emerging.^[1]

Not every option suits every ankle, and some are best done at a specialized center. We explain which make sense for you, and refer you when that is the better route.

Common questions

Can the bone recover?

In the early stages, it can. Keeping weight off the talus for a prolonged period while the blood supply returns gave the most favorable results for early AVN in a systematic review, and shockwave therapy may help alongside it.^[2] The earlier AVN is found, the more options there are.

How long will I need to protect the ankle?

Usually months rather than weeks, with regular MRI or X-ray checks to see how the bone is responding. We plan it around your work and daily life, and adjust it as the bone heals.

Why can’t you tell me which treatment works best?

Because the studies are small and uncontrolled: a systematic review rated the quality of all the evidence on talar AVN as very low.^[2] That is why we tailor treatment to the stage of the disease, your symptoms and your goals, and explain the trade-offs of each option.

When to seek care