Mallet Finger

Mallet finger is an injury that occurs when an object hits the tip of your straightened finger or thumb. It is also known as baseball finger. The blow to your fingertip causes it to bend more than normal, which tears the cord that attaches to the tip of your finger (extensor tendon).

Your extensor tendon is what straightens the end of your finger. If this tendon is damaged, you will not be able to straighten your fingertip. Sometimes, a piece of bone may be pulled away with the tendon (avulsion injury), or the tendon may tear completely. In some cases, surgery may be required to repair the damage.

What are the causes?

Mallet finger is caused by a hard, direct hit to the tip of your finger or thumb. This injury often happens from getting hit in the finger with a hard ball, such as a baseball.

What increases the risk?

This injury is more likely to happen if you play a sport that uses a hard ball.

What are the signs or symptoms?

The main symptom of this injury is the inability to straighten the tip of your finger. You can manually straighten your fingertip with your other hand, but the finger cannot straighten on its own.

Other symptoms may include:

• Pain.
• Swelling.
• Bruising.
• Blood under the fingernail.

How is this diagnosed?

Your health care provider may suspect mallet finger if you are not able to extend your fingertip, especially if you recently injured your hand. Your health care provider will do a physical exam. This may include X-rays to see if a piece of bone has been pulled away or if the finger joint has separated (dislocated).

How is this treated?

Mallet finger may be treated with:

• A splint on your fingertip to keep it straight (extended) while the tendon heals.
• Surgery to repair the tendon. This is done in severe cases. This may involve:
  • Using a pin or screw to keep your finger extended and your tendon attached.
  • Using a piece of tendon from another part of your body (graft) to replace a torn tendon.

Follow these instructions at home:

If you have a splint:

• Wear the splint as told by your health care provider. Remove it only as told by your health care provider.
• Loosen the splint if your fingers tingle, become numb, or turn cold and blue.
• Keep the splint clean.
• If the splint is not waterproof:
  • Do not let it get wet.
  • Cover it with a watertight covering when you take a bath or a shower.
• If you take your splint off to dry it or change it:
  • Gently press your finger on a flat surface to keep it straight. Failing to do so may lead to a permanent injury, or force you to wear the splint for a longer period of time.
  • Check the skin under the splint. Tell your health care provider if you notice a blister or red and raw skin.

Managing pain, stiffness, and swelling

• If directed, put ice on the injured area:
  • If you have a removable splint, remove it as told by your health care provider.
  • Put ice in a plastic bag.
  • Place a towel between your skin and the bag.
  • Leave the ice on for 20 minutes, 2–3 times a day.
• Move your fingers often to avoid stiffness and to lessen swelling.
• Raise (elevate)the injured hand above the level of your heart while you are sitting or lying down.

General instructions

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Do not drive or use heavy machinery while taking prescription pain medicine.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• You have pain or swelling that is getting worse.
• Your finger feels cold.
• You cannot extend your finger after treatment.
• You notice that the skin under the splint is red, raw, or has a blister.

Get help right away if:

• Even after loosening your splint, your finger is:
  • Very red and swollen.
  • White or blue.
  • Numb or tingling.

Summary

• Mallet finger is an injury that occurs from a hard, direct hit to the tip of your finger or thumb.
• The blow to your fingertip causes it to bend more than normal, tearing the tendon that straightens the end of your finger. You cannot straighten your fingertip if this tendon is torn.
• This injury often happens from getting hit in the finger with a hard ball, such as a baseball.
• Treatment will depend on how severe the injury is. You may need to wear a splint to keep the finger straight while it heals. A more severe injury may require surgery to repair the tendon.