A mallet finger, also known as hammer finger or PLF finger, is an extensor tendon injury at the farthest away finger joint. This results in the inability to extend the finger tip without pushing it. There is generally pain and bruising at the back side of the farthest away finger joint.
A mallet finger usually results from over bending of the finger tip. Typically this occurs when a ball hits an outstretched finger and jams it. This results in either a tear of the tendon or the tendon pulling off a bit of bone. The diagnosis is generally based on symptoms and supported by X-rays.
