The X-Ray Doesn’t Decide This One. Making a Fist Does.
You’ve broken a finger bone.
The X-ray shows a crack, the alignment looks acceptable, and someone has taped it to its neighbor.
Most of the time that’s correct treatment. But there’s one check that has to be done before anyone decides, and it isn’t visible on an X-ray at all.
Bend your fingers into a loose fist and look at them from the end. All four fingertips should point towards roughly the same spot near the base of your thumb, and none should cross over its neighbor (this is called “scissoring” and it’s a troublesome situation for any fingers)
If one crosses, the bone has healed or is sitting rotated, and rotation is the one deformity a finger cannot compensate for.
Why rotation matters more than angle
A finger bone healing at a slight angle usually causes surprisingly little trouble. The neighboring joints absorb it and most people never notice.
Rotation on the other hand…behaves completely differently, because it’s amplified along the length of the finger. A few degrees of twist at the fracture becomes a centimetre or more of overlap at the fingertip.
And a finger that crosses over its neighbour every time you close your hand doesn’t just look wrong. It gets in the way of grip, catches on things, and can only be corrected later by breaking the bone again deliberately and re-fixing it.
An X-ray is taken with the fingers straight, which is exactly the position where rotation hides. It only shows up in a fist.
You can also compare the plane of the fingernails with the hand half-closed. All four should sit roughly level, like a small row of tiles.
One tilted out of line is the same finding.
Which breaks need fixing
Broadly, surgery gets considered when:
- There’s any rotation, as above.
- The break runs into a joint surface and leaves a step or gap in it.
- The fragments are separated rather than sitting against each other.
- Angulation is beyond what that particular bone tolerates, which varies quite a bit along the finger.
- Several fingers are broken, or the bone is broken in several places.
- There’s an open wound over the fracture.
Fixation is usually wires or small screws and plates. Wires are simpler and often removed at a few weeks; plates stay unless they cause trouble.
The splint position that looks wrong and isn’t
If your hand is being splinted, the position matters enormously, and the correct one looks uncomfortable.
The big knuckles should be bent to something close to a right angle, and the finger joints beyond them held straight. Wrist slightly extended.
The reason is the ligaments. At the big knuckle, the side ligaments are at their longest when the joint is bent, so holding it bent keeps them stretched out. At the finger joints, the opposite is true, so those are held straight.
Splint a hand flat and straight instead, which is what feels natural, and those ligaments shorten in position over a few weeks. Then the fracture heals perfectly and the hand doesn’t work, because the joints have tightened while you weren’t using them.
(This is the single most useful thing I can tell you about splinting a broken hand. If your splint holds your knuckles straight, ask why.)
Recovery
- Week 0 to 3: protection, elevation almost constantly, and movement of every joint that isn’t being protected. Swelling controlled early is stiffness avoided later.
- Weeks 3 to 6: the fracture is usually sticky enough for protected movement. This is the window that decides your final range, and it’s the one people spend still waiting for a six-week appointment.
- Weeks 6 to 12: strengthening, grip work, and pushing any residual stiffness.
- Months 3 to 6: full use. Fingers that have been broken stay visibly thicker at the fracture site for a long time, and can ache in the cold for a year.
The one to watch is a break in the bone closest to the palm.
Those sit right underneath the extensor tendon, and the healing bone and the tendon can scar to each other. When that happens the finger loses bending, straightening, or both, and it needs early, deliberate movement to prevent rather than treatment to fix.
When to go back to the doctors or hand therapy immediately
- Any crossing over of the fingers as you make a fist, at any point in the recovery.
- Range that has stopped improving between weeks 3 and 8.
- Increasing pain and swelling after the first fortnight.
- Numbness in the finger that wasn’t there at the start.
The short version
Broken finger: make a loose fist and check whether it crosses. That check outranks the X-ray, and it should be done before anyone commits to taping it up.
Then get the splint position right, and start moving at three weeks rather than six.
Most broken fingers heal fine. Most stiff fingers were broken fingers that healed fine and weren’t moved.
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. A finger that crosses over its neighbour needs assessing, not taping.