Tendon transfer in foot and ankle at Wessex Hospital

A tendon transfer is an operation that takes a healthy, working tendon and moves its point of attachment, so it can take over the job of a tendon that's stopped working properly. The tendon stays connected to its own muscle, blood supply and nerve, but is rerouted to a new bone or tendon to restore movement you've lost.

What conditions does it treat?

This surgery treats a range of problems that stop a tendon working properly. It's considered for:

• flat feet caused by a damaged or overstretched posterior tibial tendon, the tendon that supports your foot's arch, which makes the foot roll inwards
• foot drop, where you can't lift the front of your foot, usually from damage to the nerve that controls this movement
• nerve or muscle conditions such as Charcot-Marie-Tooth disease, cerebral palsy, multiple sclerosis, or the after-effects of a stroke
• nerve damage following spinal injury, a slipped disc, or spinal surgery
• direct injury to a tendon or the nerve that supplies it, including some cases of an Achilles tendon tear that wasn't treated early on
• toes that curl or claw only when you're standing, if the toe joints are still flexible.

What are the benefits of having a tendon transfer?

Tendon transfer aims to restore movement, strength and stability at the affected joint, and can reduce pain caused by walking awkwardly to compensate for the lost movement. For some people, it also helps avoid the need for a brace they might otherwise need to wear long-term.

This type of surgery tends to work best, and recovery goes most smoothly, when it's followed by a structured rehabilitation programme, since regaining strength and coordination in the transferred tendon takes practice. Being motivated to follow your physiotherapy plan closely is one of the strongest predictors of a good result.

Are there different types or surgical approaches?

The tendon used, and where it's moved to, depends entirely on which muscle has stopped working and what needs restoring. For painful flat feet, the flexor digitorum longus tendon, found underneath your toes, is commonly used to replace a damaged posterior tibial tendon, often alongside a procedure to realign the heel bone.

For foot drop, the tibialis posterior tendon, from the inner ankle, is often rerouted to the top of the foot to restore the ability to lift it. For toes that curl only on standing, a tendon from underneath the toe can be split and rerouted to straighten the toe joint instead. Your surgeon will choose the option best suited to exactly which muscles are and aren't working for you.

Sometimes, if the joints in the foot have become too stiff or unstable for a tendon transfer to work well on its own, a bone-fusion operation is used instead, or alongside the tendon transfer.

What happens before the operation?

Before surgery, your team needs to understand exactly which muscles are and aren't working, and whether the deformity can still be corrected.

• You'll have a detailed examination testing the strength of different muscles in your foot and leg, often asking you to move your foot and toes in specific ways while seated
• X-rays are usually taken to check the bones and joints in your foot haven't become too damaged or unstable for a tendon transfer to work well
• If your Achilles tendon has become tight, this is usually stretched or released, either before your operation or during the same one
• Non-surgical options, such as bracing, splinting and physiotherapy, are generally tried first, often for up to a year, since some nerve-related problems can improve on their own in this time
• You may be given exercises to strengthen the donor muscle, the one being moved, beforehand, to give it the best chance of working well in its new role
• Tell your team about any previous surgery, scarring, or skin problems in the area, since these can affect how well the transfer works.

What happens during the procedure?

While the exact steps depend on which tendon is being moved, a typical tendon transfer involves:

1. You're given a general, spinal or regional anaesthetic, and a cuff is often used on the leg to limit bleeding during the operation
2. Your surgeon makes one or more incisions to reach both the damaged tendon and the healthy one being used for the transfer
3. The damaged tendon is removed or trimmed back if it can't be repaired
4. The healthy tendon is carefully freed up and detached from its original attachment point, keeping its blood and nerve supply intact
5. It's guided through the soft tissue, sometimes through a small tunnel drilled in a bone, to reach its new attachment site
6. It's fixed firmly in place using stitches, a small anchor or a screw, with your foot held in the correct position and the tendon tensioned carefully, neither too loose nor too tight, before the wounds are closed.

What does recovery look like?

Many tendon transfers involve a hospital stay of a couple of nights, though this varies depending on which tendon is moved and your general health. Your foot will be placed in a splint or cast, and you'll be shown how to keep it raised to help with swelling.

You will usually need to avoid putting weight on the foot for around 6 weeks, using crutches to get around. Your splint typically will stay on for the first 10–14 days, after which a cast or removable walker boot protects the area for several more weeks.

Physiotherapy plays a big part in your recovery, helping you retrain the transferred tendon and rebuild strength once your surgeon says it's ready. Timeframes for the later stages of recovery can differ: a structured return to standing at around 4 weeks and full weight-bearing from 8 weeks, but you may need to wear a cast or boot for up to 12 weeks, with return to demanding physical activity around 3 months and a fuller recovery over about a year. Because everyone's situation is different, your own surgeon and physiotherapist will set out the timeline that applies to you.

What are the risks and complications?

As with any operation on a tendon, there are risks to be aware of, including:

• infection, bleeding, or problems related to the anaesthetic
• the transferred tendon not healing properly, tearing, or coming loose from its new attachment
• reduced movement if the tendon becomes stuck down to the surrounding tissue, particularly where the tissue bed is scarred from a previous operation or burn
• weakness, or the original problem coming back over time, especially if the underlying nerve condition continues to progress
• numbness, tingling or nerve pain, if a nerve near the surgical site is affected
• needing further surgery, including in some cases a bone-fusion procedure, if the transfer alone doesn't fully correct the problem.