This condition is an injury to the end of the extensor tendon that straightens the finger’s end joint, called the DIP joint. It results in drooping of the fingertip and prevents the finger from being straightened. Causes This condition is caused by an injury to the extensor tendon at the DIP joint. It can be caused by a laceration to the back of the finger, but most commonly results from direct trauma, often during sports when a ball strikes the extended finger. This can violently flex the tip of the finger, rupturing the extensor tendon. In some cases the tendon is pulled away from the bone, breaking a piece of bone from the tendon’s attachment point. This type of injury is called a bony mallet finger.
The main symptom of this condition is a downward turning of the tip of a finger and an inability to straighten the affected finger. Other symptoms, which are most commonly associated with bony mallet finger, may include pain, swelling or tenderness.
Mallet finger is commonly treated by placing the affected finger in a splint for at least eight to twelve weeks. If the bone fragment is very large or the joint is displaced, surgery may be recommended.