A tendon transfer takes a working muscle you can spare and re-routes its tendon to do the job of one that has failed. The surgery moves the wiring. The rehab teaches the brain.
That second half is the whole game: a technically perfect transfer that never gets re-trained gives you a finger that moves only when you do something unrelated… and patients are almost never warned about that part beforehand.
When it’s offered
Transfers come up when a muscle or its nerve is beyond repair, not merely injured.
- A nerve palsy that hasn’t recovered — radial, ulnar or median — where waiting longer will not help
- A tendon rupture that can’t be stitched back, such as an EPL rupture after a wrist fracture, where the frayed ends are useless
- Rheumatoid tendon ruptures at the wrist
- Old injuries where a nerve repair was done too late or didn’t take
The classic example: after a radial nerve palsy, the wrist and fingers won’t lift. A transfer borrows wrist flexors to lift the fingers instead. You keep bending your wrist — there’s another muscle for that — and you gain back the ability to open your hand.
A transfer never creates power. It redistributes it. You are always trading something you have for something you need more.
The four rules that decide the result
Surgeons plan against these. Knowing them makes the conversation before surgery a lot more useful.
The joint must move first. A transfer into a stiff finger achieves nothing. If your hand is stiff, the therapy to regain passive range happens BEFORE the operation, not after. This is the single commonest reason a transfer gets delayed.
The donor must be strong and expendable. A transfer loses roughly a grade of strength once moved. A weak donor gives a weak result.
Straight line of pull. Tendons that have to turn corners lose force and stick down.
One tendon, one job. A donor asked to do two things does neither cleanly.
The rehab, week by week
- Weeks 0 to 3 or 4 — splinted in a position that keeps all tension off the new join. No active use. The join is just healing tendon, and tendon at three weeks is weaker than it feels.
- Weeks 4 to 6 — the re-education phase. Short, frequent sessions. You’ll be asked to perform the donor’s OLD action to produce the new movement, which feels absurd the first fifty times.
- Weeks 6 to 8 — the movement starts happening without the old cue. This is the moment patients describe as a switch flipping.
- Weeks 8 to 12 — light functional use. Strength work begins carefully.
- Month 3 to 6 — resistance, endurance, return to work. Heavy manual work often sits at the far end of that.
- Month 6 to 12 — the movement becomes automatic. Many people plateau earlier than this and then improve again with use.
The re-education phase is where I earn my keep. It is repetitive, it looks like nothing is happening, and then one day the finger just lifts.
What to expect honestly
You will not get a normal hand back. You get a functional one.
Expect a strength grade below the original. Expect the two movements the donor is involved in to interfere with each other early on. Expect some adhesion, which is why the early controlled movement matters.
And expect the new movement to disappear temporarily when you’re tired, stressed or concentrating on something else. That’s normal in the first six months, not a sign the transfer failed.
The surgeon gives you a new cable. The re-training is what connects it to your intention.
Before you agree to one, ask
- What am I giving up, and what will I notice about losing it?
- Is my hand passively supple enough today, or does that need work first?
- How many rehab sessions is this, realistically, and who is doing them?
- What is the plan if this transfer doesn’t take?
If nobody has answered the third question, the surgery isn’t ready to be booked. A tendon transfer without a rehab plan is an operation with the second half missing.
For the splint used, see the wrist drop splint and the anti-claw splint.
Every article on this site is written using the Closing Window Method: name the window your condition runs on, find where you are in it, and act while it’s still open.