Monday, October 22, 2012

Mallet Finger: What Is It And How Do I Fix It?

A patient of mine came into the office last week complaining she couldn't straighten out her finger any more.
Two weeks ago she had been playing Volleyball and took a ball off the tip of her right ring finger. She said she could still continue playing despite the pain, but since then hadn't been able to straighten the tip of that finger any longer.

Mallet Finger: What Is It?
This very pleasant lady had suffered a tear to the extensor tendon of her ring finger. The mechanism of injury was classic. People will typically describe a direct blow to the affected finger when it is fully extended (ie straightened out). This usually will be a ball striking the tip of the finger, but occasionally happens when they run into something/someone with the finger straight out. With the tip of the finger straight, the force of the blow ends up tearing the extensor tendon off the bone, and the individual can no longer lift or straighten up the last joint of the finger.

When the tendon is torn away, it takes a little chip of bone with it, and is readily seen on plain x-rays (above).

How Do I Diagnose It?
First, my suspicion is quickly aroused with the typical history of injury. Secondly, to examine the finger, the diagnosis is usually confirmed seeing the tip of the finger hanging down (looks like a mallet, thus the nickname!)

The patient, when asked, will NOT be able to lift, or extend, the tip of the finger, confirming that the tendon is ruptured. Finally, for confirmation, I will take an x-ray to both confirm the diagnosis, and ensure that not too large a piece has broken away, and that the joint is still reasonably intact.

How Do I Fix It?
For the vast majority of patients, using a splint, HYPEREXTENDING the tip of the joint for a period of about 6 weeks allows the torn extensor tendon to reattach itself and heal.

There are commercially available splints, but I find they often don't fit snugly enough, and don't hyperextend the joint far enough. Much easier, at least for me, is to cut a piece of aluminum splint to the right length, and bend it to the degree of extension I want. Most IMPORTANTLY, I make sure that the middle joint of the finger is allowed to continue moving freeely, so that it doesn't stiffen over the period of immobilization. I also tell patients that when they are changing the tape, or cleaning the finger, to keep holding the tip of the finger in hyperextension, and NOT let it fall back down, ensuring that the torn tendon remains in contact and continues healing. I will sometimes tell them that if they let this happen, their 6 week clock has to restart again!

On rare occasions, the chip of bone is too large, or the joint is out of alignment. In these cases, I will send patients on to a plastic surgeon to discuss surgically correcting the digit. I will also, on occasion, depending on the person's occupation (ie professional piano player, etc), send them for a surgical opinion irregardless.

Final Note: I like to follow up with these individuals after 4-6 weeks and get a new xray and examine them again to ensure healing.

Have you ever suffered this injury? How was it treated? How did everything turn out?
Let me know!


  1. Is it possible to heal this injury after a significant amount of time has passed. Say after 10 years?

    1. Probably not. The extensor tendon will have retracted (shortened), leaving even surgery to repair an unlikely option.