Tibiotalocalcaneal (TTC) Fusion

A TTC fusion (full name: tibiotalocalcaneal arthrodesis) joins two worn-out joints — the ankle joint and the joint just below it, the subtalar joint — into one solid unit, turning a painful, unstable or badly aligned ankle and heel into a strong, stable foot you can stand and walk on. It is usually recommended when the damage is too severe for simpler treatments. The main benefits are:

• Lasting pain relief. Fusing the joints stops the worn, painful surfaces rubbing, which is often the single biggest change patients notice.
• A stable, straight foot. The operation corrects deformity and sets the foot flat to the ground (surgeons call this a “plantigrade” foot), making standing and walking far easier and safer.
• A solution when other options have failed. It is a reliable choice when there is major bone loss, a failed previous ankle fusion, or a failed total ankle replacement, and when the joint below the ankle is also worn out.
• A limb-saving procedure. In the most severe cases — for example after serious injury, loss of blood supply to the ankle bone, or nerve-related (Charcot) damage — a TTC fusion can be the alternative to amputation.
• A well-proven operation. Published results show most patients heal successfully (union rates of around 90%) with large improvements in pain and day-to-day function.

The main trade-off is that the fused ankle and hindfoot no longer bend up and down. In practice most patients find the pain relief and stability well worth it, and a rounded (“rocker”) sole on the shoe restores a smooth stride.

Good preparation makes recovery smoother. Before your operation you will usually attend a pre-assessment clinic for a health check and blood tests, and any regular medicines (including blood thinners) will be reviewed.

• Stop smoking. Smoking greatly reduces the chance of the bones fusing. Stopping well before surgery is one of the most important things you can do.
• Plan your home. You will be non-weight-bearing at first, so set up a downstairs space if you can, keep everyday items within reach, and arrange help for the first couple of weeks.
• Sort out kit in advance. Two simple items make the early weeks much easier:
  • A foam leg elevator — a wedge to rest your leg on so it stays raised above heart level, which reduces swelling and pain and helps the wound heal.
  • A waterproof cast protector (such as the “Limbo” cover) — to keep your plaster and dressings completely dry so you can shower or bathe safely.

Mr Welck’s team can advise on preparing for your foot and ankle surgery and on recommended products and equipment for your recovery period.

The operation is done under a general anaesthetic (fully asleep) or a spinal anaesthetic (numb from the waist down), and usually takes a couple of hours. In simple terms:

• The surgeon makes an incision on the outer side of the ankle to reach both the ankle joint and the joint below it.
• The worn-out cartilage and any damaged or dead bone are carefully cleared away, and the alignment of the ankle and heel is corrected so the foot sits flat and straight.
• Bone graft — often taken from the side of your own ankle (the fibula) — is packed into the gaps to encourage the bones to knit together.
• A metal rod (called a nail) is then passed up through the bottom of the heel, through the heel bone and ankle bone, and into the shin bone. It is held firmly in place with a few small screws.
• This nail acts as an internal scaffold, holding everything perfectly still and in line while the bones fuse into one solid unit over the following weeks.

The metalwork usually stays in permanently and causes no problems. It is only removed in a small number of cases if it becomes prominent or irritating.

Most patients stay for one night and go home the day after surgery. While you are in, you will have pain relief, antibiotics, and an X-ray to confirm the position. Your leg will be in a plaster splint (a “backslab”), and the team will make sure you are comfortable and safe on crutches before you go home.

Fusion surgery asks for patience: the bones need time to knit together, and rushing it risks the fusion failing. Recovery is best thought of in three stages.

Early — the first 2 weeks

• You rest at home with the leg elevated as much as possible to control swelling.
• You will be non-weight-bearing (no weight through the foot) in a plaster splint, using crutches or a frame to get about.
• You will be on blood-thinning treatment to reduce the small risk of a clot in the leg while you are less mobile.
• At around 2 weeks you return to clinic for a wound check, after which the splint is changed to a full plaster cast.

Mid-term — weeks 2 to 12

• Weeks 2–4: non-weight-bearing in the plaster cast — still no weight through the leg.
• Weeks 4–8: partial weight-bearing with crutches — you begin to put some weight through the leg, guided by your surgeon.
• Weeks 8–12: full weight-bearing in the plaster — walking with your full weight through the cast.

Long-term — from around 12 weeks

• Weeks 12–15: you move into a removable walking boot and begin weight-bearing in the boot as the fusion consolidates.
• You are then gradually weaned out of the boot into a supportive shoe, often with a rounded (“rocker”) sole to give a smooth stride.
• Physiotherapy helps you rebuild strength, balance and walking pattern. Swelling can take several months to settle, and the final result can take up to a year.

Getting back to activity and sport

Most patients return to comfortable, pain-free walking and everyday activity. Many patients return to gentle, low-impact exercise once the fusion is solid, though high-impact running is usually limited by the fused joints. Mr Welck will give you advice tailored to your goals.

TTC fusion is a major operation and, like any surgery, carries risks. Mr Welck will discuss these with you in detail. The risks most specific to this particular procedure are:

• Non-union or delayed union — the bones may be slow to fuse, or not fuse fully. This is more likely in smokers, people with diabetes, poor blood supply or nerve conditions, and may need further surgery.
• Malunion — the foot may heal in a slightly less-than-perfect position.
• Nerve injury or numbness — small nerves around the ankle and foot can be bruised or, rarely, damaged, causing numbness or altered sensation.
• Metalwork irritation — occasionally a screw or the nail becomes prominent and needs removing at a later date.
• Infection — as with any surgery; antibiotics are given to reduce this risk.
• Stiffness and altered walking — the fused joints no longer move, which is expected. Some patients have a slight limp or a small difference in leg length, and over many years the neighbouring joints can wear a little faster.

For a full explanation of the general risks that apply to hindfoot fusion surgery, please read the Stanmore Foot & Ankle Specialists Hindfoot Surgery Risks leaflet.