A triple hindfoot fusion — also called a triple arthrodesis — is an operation that permanently joins the three main joints at the back part of the foot: the subtalar joint (just below the ankle), the talonavicular joint, and the calcaneocuboid joint. By fusing these joints together, the surgery corrects the shape of the foot and removes the worn, painful movement that is causing symptoms.

The hindfoot is the powerful “engine room” that links your ankle to the rest of your foot. When these joints become arthritic or badly deformed, every step can hurt, and the foot may gradually collapse into a flat or a high-arched, twisted position. A fusion trades movement in these joints for a stable, well-aligned and much less painful foot.

Common reasons for a triple fusion

• Severe, fixed hindfoot deformity that can no longer be helped by insoles, braces or joint-preserving surgery
• Arthritis (worn-out cartilage) of the hindfoot joints, often after an old injury or with inflammatory conditions such as rheumatoid arthritis
• Advanced flatfoot (a collapsed arch) caused by failure of the posterior tibial tendon and the supporting ligaments
• A rigid, painful high-arched (cavus) foot
• Persistent pain, swelling and stiffness that limits walking and daily activities

The benefits

The goal is a plantigrade foot — one that sits flat and evenly on the ground — that is stable, well-aligned and far more comfortable. Most patients gain significant pain relief, walk more easily, and can wear normal shoes again. The fused joints will no longer bend, but in a foot that was already stiff and painful this is a worthwhile trade for lasting comfort and stability.

Good preparation makes recovery smoother. Before your operation you will normally attend a pre-assessment appointment, where your general health, medicines and any allergies are reviewed. A few simple steps make a real difference:

• Arrange time off work and help at home — for the first two weeks the leg must stay elevated, so plan for support with cooking, shopping and childcare.
• Set up a comfortable “recovery station” on one level, close to a bathroom.
• Get crutches early and practise using them before your surgery date.
• A foam leg elevator is strongly recommended. Keeping the foot higher than your heart reduces swelling, eases pain and protects the healing wounds.
• A waterproof cast protector (such as the “Limbo”) lets you shower without getting the plaster wet.
• Stop smoking well before surgery — smoking greatly increases the risk of the bones failing to fuse and of wound problems.

For a helpful checklist of recommended recovery items, see the Stanmore Foot & Ankle Specialists Product Guide.

The operation is carried out under anaesthetic — usually a general anaesthetic, often combined with a nerve block that numbs the leg and helps to control pain afterwards.

You are positioned lying on your back, which lets the surgeon reach both the outer and inner sides of the foot. Two small cuts are usually made — one on the outside and one on the inside.

Through these openings, the surgeon carefully removes the worn or damaged cartilage from the three joints and prepares the bone surfaces so they can knit together. The foot is then moved into a straight, corrected position. If the calf muscle or Achilles tendon is tight, it may be gently lengthened at the same time so the foot can sit correctly.

The joints are held firmly in their new position with small metal screws (and sometimes a plate or staple). Bone graft — tiny chips of bone — is often packed into any gaps to encourage healing. Over the following weeks and months the bones gradually grow together into one solid block, which is what makes the correction permanent. The wounds are closed with stitches and the leg is placed in a plaster.

Most patients stay in hospital for one night. This overnight stay lets the team keep your pain well controlled, keep the leg elevated to limit swelling, and make sure you are safe and confident on your crutches before you go home.

Recovery is a gradual process, because the bones need time to fuse into one solid unit. It helps to think of it in three stages.

Early recovery — the first 2 weeks

You will be at home with the leg strictly elevated as much as possible — ideally “toes above the nose.” This is the single most important thing you can do to reduce swelling and protect the wounds. You will take blood-thinning tablets during this period to lower the risk of a clot (deep vein thrombosis). You will then be seen in clinic so the wounds can be checked and the stitches removed.

Midterm recovery — protected healing in plaster (weeks 2–12)

• Weeks 2–4: non-weight-bearing (no weight through the foot at all) in a full plaster cast.
• Weeks 4–8: partial, crutch-assisted weight-bearing in a full plaster.
• Weeks 8–12: full weight-bearing in a full plaster.

Throughout this time you will attend regular clinic appointments, and X-rays are taken to confirm the bones are fusing well.

Long-term recovery — 3 months onwards

Once the plaster is removed and X-rays confirm the fusion is solid, you gradually return to normal footwear and build up your activity. Swelling can take several months to fully settle, and it may be six to twelve months before you feel the full benefit. Physiotherapy helps rebuild strength, balance and confidence. Most people return to comfortable everyday walking and low-impact activities; because the fused joints no longer move, some high-impact sports may remain limited.

Every operation carries some risk. The main risks specific to a triple hindfoot fusion are:

• Non-union — the bones fail to fully knit together, which can occasionally require further surgery. Smoking greatly increases this risk.
• Malunion — the foot heals in a slightly less-than-ideal position.
• Wound-healing problems — more likely on the outer incision when correcting a large flatfoot deformity.
• Nerve irritation — the sural nerve on the outer side of the foot can be bruised, causing numbness or tingling.
• Prominent metalwork — screws can occasionally be felt under the skin and may be removed later if troublesome.
• Adjacent-joint arthritis — over many years, the joints next to the fusion (particularly the ankle) may wear a little faster.

For a fuller explanation of the general risks of hindfoot surgery — including infection, blood clots and anaesthetic risks — please read the Stanmore Foot & Ankle Specialists Hindfoot Surgery Risks leaflet.