Foot fusion surgery is an operation that fuses one or more joints in the foot into a fixed position. This eliminates joint motion that may cause pain for people with certain conditions, such as arthritis.

Sometimes, foot fusion surgery also improves the position of the foot or ankle.

During the procedure, a surgeon removes the joint surfaces and reshapes them if necessary. The next step involves putting the surfaces back together and affixing with a screw, pin, or plate.

Keep reading to learn more about foot fusion surgery, including its uses, the procedure, recovery, postoperative exercises, complications, and whether it is worth undergoing.

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Foot fusion surgery, or foot arthrodesis, is a procedure that joins two or more bones together. After the surgery, the joint is in a fixed position and can no longer move.

There are two main types of foot fusion surgery: midfoot and hindfoot.

Midfoot

The midfoot refers to the middle of the foot, which includes the arch and the associated bones, tendons, and ligaments. It connects the front part of the foot — the forefoot — to the back of the foot, or hindfoot.

Hindfoot

The hindfoot includes the heel and the joints that sit below the ankle. Hindfoot fusion surgery entails joining one, two, or three joints together, notes an older 2016 study.

The fusion of three joints, called triple arthrodesis, actually affects joints in both the midfoot and hindfoot. It has the disadvantage of resulting in a loss of range of motion, since it fuses three joints rather than one or two.

For this reason, less extensive foot surgeries are a better choice when possible. However, triple arthrodesis can help many people with significant structural problems in the foot to have a pain-free gait.

According to a 2021 review, doctors may recommend foot fusion for people with:

  • degenerative arthritis
  • bunions, which are a painful malformation involving the big toe
  • flat feet, which is when the arch of the foot falls or is flat
  • fractures
  • ligament injury
  • a Lisfranc injury, which involves damage to the bones or ligaments in the midfoot
  • neuroarthropathy, which is a condition involving the joints and nerves

Doctors may use triple arthrodesis when less extensive procedures are not the best choice. They may recommend this procedure to people with:

  • degenerative or post-traumatic arthritis
  • severe flat feet
  • canvas foot, which involves a high arch
  • clubfoot, or a severe turning inward of the bottom of the foot
  • neurological conditions that result in a forward-propelling gait, such as:
    • cerebral palsy, which affects movement due to brain damage before birth
    • spina bifida, which is when the spine does not completely develop during pregnancy
    • Charcot-Marie-Tooth, which is a group of inherited conditions that cause nerve damage

During foot fusion surgery, health professionals will:

  1. Administer local or general anesthetic. Local anesthetic only numbs a certain area while a person remains awake. General anesthetic makes a person sleep during the surgery.
  2. Make one or more incisions in the foot to access the joints.
  3. Open up each joint that requires fusion, removing the surfaces of the joints. If necessary, a surgeon may also reshape the joints to correct structural problems.
  4. Move the joint surfaces into the correct position and affix them with plates, screws, or staples.
  5. Insert extra bone tissue into the joint if necessary. Surgeons may do this using some of the bone they removed, or if there is not enough, they may take a bone graft from the top of the shin, below the knee.

A complete recovery from foot fusion surgery can take up to 6 months, depending on the type of fusion surgery.

Immediately after the procedure, people may spend 2 to 3 days in the hospital. The foot will swell up, requiring a person to rest with the foot raised.

When the initial swelling lessens, health professionals will apply a cast to keep the foot still as the bones fuse together over time. They may do this before a person goes home or a few days later.

At home, it is essential to rest as much as possible during the first 2 weeks. A person will need to use crutches when getting up to avoid putting weight on the foot.

People will need to wear the cast for around 8 to 12 weeks. At around 6 weeks, they may return to a hospital or clinic to have the cast removed and receive follow-up X-rays. If healing is going well, a doctor will replace the cast with a removable boot, which a person can begin putting some weight on.

If the joints have not fused enough for this to be safe, a person may need a new cast and to delay putting weight on the foot for longer. Walking on the foot too soon will impede recovery.

Foot exercises can help keep muscles strong as a person heals from fusion surgery. A doctor will tell a person when it is safe to begin these.

A physical therapist will provide a tailored set of instructions depending on the type of surgery a person had, but some examples of exercises the physical therapist may recommend include:

  • moving the non-operated ankle up and down.
  • gently moving the toes of both feet up and down
  • lying down with straight legs, lifting one up, and then gently releasing back down
  • sitting in a chair or on the edge of a bed and straightening one leg, holding, and releasing

Following the removal of the cast, an individual can increase activities such as walking or cycling, as long as a doctor approves this. They can progress to more vigorous activity as flexibility and comfort improve.

Potential complications of this procedure include:

  • swelling in the foot, which can take many months to completely disappear
  • adverse reactions to anesthesia
  • incomplete healing, which may require further surgery
  • slow healing, which necessitates extra dressing changes and monitoring
  • minor infections in the wound
  • more serious infections in the bones, which only happen in 1% of cases
  • loosening of screws or pins in the joint, which requires minor surgery for removal
  • chronic, or long-term pain
  • formation of a blood clot in the leg or lungs

Foot fusion seems to have favorable results for most people.

A 2021 study indicates that midfoot fusion can successfully achieve and maintain structural corrections. The rate of bone fusion among the 62 participants was 94%. When excluding people who smoked or who had neuroarthropathy, the rate was 100%.

People can promote healing and recovery after the surgery by:

  • stopping smoking beforehand, if applicable
  • following wound care instructions
  • not putting weight on the foot until a doctor approves it
  • monitoring for any signs of complications and reporting them early

Signs that the foot may not be healing as it should following surgery include:

  • pus, drainage, or warmth around the wound
  • fever
  • clammy skin
  • pain that keeps getting worse or does not respond to medication
  • feeling generally unwell
  • a wound that will not heal

Foot fusion surgery puts one or more joints in a fixed position in the midfoot, hindfoot, or both. Doctors use it to correct structural problems in the feet and promote pain-free walking in people with a variety of conditions, including arthritis.

Foot fusion involves a short hospital stay. After that, a person will need to wear a cast for several months. In the postoperative period, someone can do gentle exercises to increase range of motion and muscle strength.

While foot fusion surgery is usually successful, there are some risks and complications that can occur. A doctor will help a person weigh the benefits and risks of the procedure for each situation.