Mallet Finger

What it is

In a mallet finger, the end joint of the finger droops and cannot be straightened on its own, giving the finger the shape of a mallet. The extensor tendon that straightens this joint has either torn, or a small piece of bone where it attaches has broken off.

What causes it

A ball or other object striking the fingertip is the classic cause, which is why it is sometimes called “baseball finger.” It can also happen with surprisingly little force, such as tucking in a sheet or bumping a drawer, or from a cut on the back of the finger.

Symptoms

• A drooping fingertip that you cannot straighten, although it can be pushed straight
• Pain, swelling, or bruising over the end joint
• Sometimes blood under the nail or a nail lifting at its base

Diagnosis

Seek care within the first few days. An X-ray shows whether there is a fracture and whether the joint is aligned. Blood under the nail, a loose nail, or a cut over the joint can signal a nail bed injury or open fracture and should be seen promptly.

Treatment

Splinting: most mallet fingers heal without surgery. Until you are seen, ice, elevation, and a clean popsicle stick taped loosely along the finger can hold it straight. The end joint is then kept straight in a splint at all times, usually for about eight weeks; bending it even once with the splint off can set back healing. Afterward, the splint is worn at night and for sports for several more weeks. Your surgeon or therapist will show you exercises for the middle joint during splinting and for the stiff end joint afterward.

Surgery: may be considered when there is a large bone fragment, the joint is out of alignment, or a splint is difficult to wear or has not worked. Options include wires or small screws, a pin to hold the finger straight, repairing or rebuilding the tendon, or fusing the joint.

Recovery

Most fingers regain acceptable function and appearance. A slight droop, bump, or change in contour can be permanent. Treatment started weeks after the injury can still work, though results are less predictable.