An ULNAR GUTTER splint holds the ring and little fingers with the knuckles bent and the wrist slightly back. A RADIAL GUTTER splint does the same for the index and middle fingers.
Both are used for metacarpal and finger fractures, most often the boxer’s fracture of the little finger knuckle.
The knuckles are held BENT on purpose: it’s the position that stops them stiffening while the bone heals.
How it’s shaped, and why
- Two fingers, not one. A fractured metacarpal is held with its neighbor, so the fingers can’t pull against each other
- Knuckles bent, roughly 60 to 90 degrees. The ligaments at the sides of the knuckles are longest in this position. Held straight for weeks, they shorten and the knuckle can be slow to bend again
- Finger joints straight. The front of the middle joint shortens if it’s held bent, so it’s held straight instead
- Wrist slightly extended, which relaxes the tendons pulling on the fracture
- Thumb and the other two fingers free
Knuckles bent, finger joints straight. Get that wrong and the stiffness outlasts the fracture.
What it’s used for
- Ulnar gutter: boxer’s fractures, ring and little finger metacarpal shaft fractures, and fractures of the base of those fingers
- Radial gutter: index and middle finger metacarpal and finger fractures. The thumb gets a cut-out so it stays free
- After surgery for the same fractures, once the wound allows
Rotation: the check that matters most
Before and after the splint goes on, make a gentle fist.
If the injured finger crosses its neighbor, the fracture has rotated. A splint won’t correct that, and it needs a surgical opinion.
A typical timeline
- Weeks 0 to 3: splint on full time. Move the free fingers, elbow and shoulder every day. Hand raised to control swelling
- Weeks 3 to 4: out for gentle bending and straightening exercises
- Weeks 4 to 6: splint weaned, light use, tendon glides
- Weeks 6 to 10: grip strengthening. Contact sport and heavy work return around here
Many stable boxer’s fractures now heal well with a shorter spell of support or a hand-based brace. Your clinician decides based on the angle and rotation.
Problems to watch for
- Swelling that makes the straps tight
- Pressure over the bump at the base of the little finger or along the side of the hand
- Stiff knuckles after it comes off. See stiff hand after a cast or splint
Get it checked if
- A finger crosses another when you make a fist
- Numbness or color change in the fingers
- Pain rising instead of settling after the first week
- The splint has slipped so the knuckles are no longer bent
This is one of dozens of splints a hand therapist makes. See what a hand therapist does for the full list.
Two fingers held together, knuckles bent, and a fist check for rotation.
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.