The Splint Is the Operation. The Surgery Just Makes It Possible.
Finger joint replacement is offered mostly for badly damaged knuckles in rheumatoid arthritis, and sometimes for severe osteoarthritis in the middle joints.
It reliably delivers two things: less pain, and better alignment. Fingers that have drifted sideways get straightened, and a hand that had become hard to look at and hard to use gets both back.
It does not usually deliver more movement, and it never delivers more strength.
Getting that clear beforehand is most of the difference between a satisfied patient and a disappointed one, because the operation itself is usually fine.
What’s actually put in
The commonest implant is a one-piece silicone spacer with two stems that sit inside the bones on either side. It isn’t a hinge and it doesn’t have moving parts. It’s a flexible spacer that holds the bones apart at the right distance and bends when you bend.
Around it, your body forms a capsule of scar tissue over the following weeks. That capsule is what actually holds the finger in alignment long-term, and it forms in whatever position the finger is held while it heals.
Which is why the splinting matters so much.
The surgeon puts the fingers straight. The splint decides whether it stay straight or not.
There are also harder implants, including pyrocarbon and surface replacements, used more often at the middle joint in osteoarthritis and in more active hands. Different implant, same principle: the soft tissue around it decides the result.
The after-surgery rehab, which is unusually demanding
Expect to be in a splint for around 6 to 8 weeks, and expect it to be more involved than a plain resting splint.
For knuckle replacements in rheumatoid arthritis, that usually means a dynamic splint: a frame across the back of the hand with small elastic slings supporting the fingers. It holds them straight and aimed slightly away from the little finger, correcting the drift, while still allowing you to bend against the elastic.
You wear it through the day, do specific exercises in it, and swap to a resting splint at night.
- Days 0 to 5: bulky dressing, elevation almost constantly, shoulder and elbow moving.
- Week 1 to 6: splint fitted, controlled movement started under supervision. Little sessions, often, rather than long ones.
- Weeks 6 to 12: splint weaned gradually, usually night-only first. Light functional use built up.
- Months 3 to 6: the finished result. Range and alignment settle.
Realistic range afterwards at the knuckles is often somewhere in the region of 40 to 60 degrees of bending. If you went in with more than that, you may end up with less movement and a better hand, and that trade needs discussing before rather than after.
The lifelong restriction
This is the part to take seriously, because it doesn’t expire at three months.
Silicone implants can fracture and loosen under load. That means no heavy power grip, no forceful pinch, no using that hand to open stiff jars, wield heavy tools or carry heavy loads by the fingers.
Joint protection strategies, built-up handles, jar openers and using the other hand for heavy tasks aren’t temporary post-op advice here. They’re how you make the implant last.
Implants do wear out and fracture over years. Many still function well even when broken, and revision is possible, but the loading habits you build in the first year decide how long you get.
Things to report
- Fingers drifting sideways again as the splint is weaned. Early adjustment of the splint program can catch this.
- Spreading redness, heat, discharge or fever. Infection around an implant is serious.
- A sudden change in shape, alignment or movement, which can mean implant fracture or dislocation.
- Range that has stopped improving between weeks 4 and 10.
The short version
Go in for pain relief and alignment. Don’t go in expecting a hand that grips harder or bends further.
Then wear the splint exactly as prescribed for the full six to eight weeks, because the scar capsule forming around the implant is what actually holds your result.
And protect it for good afterwards. This is one of the few operations on this site where the restrictions are permanent by design.
Written by Nigel Chua, hand occupational therapist in practice since 2005. Tens of thousands of hands, wrists and elbows assessed and treated. My credentials are here. This article explains; it doesn’t examine. Follow your own surgeon’s and therapist’s protocol over anything here.