Mallet finger refers to a condition in which the end joint of a finger bends but will not straighten by itself. In this situation, the joint can be pushed straight but will not hold that position on its own.
The mechanism which straightens the end joint has been disrupted. This usually happens when the tip of the finger is pushed down while the person is trying to straighten their finger.
The tendon which pulls on the end bone to straighten the finger pulls one way, and the force on the end of the fingertip pulls the other way, and something comes apart in between. Often, the tendon tears away from its attachment to the bone.
Sometimes, the tendon comes off with a piece of bone attached.
In worse cases, the tendon comes off with a fairly large piece of bone, which can make the rest of the joint slide out of alignment. Fortunately, that is not very common.
What Can You Do?
Don't just ignore it. Some people ignore a bent finger, assuming that it will straighten out on its own. This is unlikely to happen. The longer the finger stays bent, the harder it will be to fix.
What Can You Use to Help?
Confirm that this actually is the problem.
Prescribe hand therapy and a custom prescription splint.
In some cases, perform surgery to reconstruct the attachment of the tendon. This type of surgery is usually not necessary unless the injury is from a cut on the back of the finger
If the finger can not be maintained straight with splinting, it may be helpful for the surgeon to place a temporary metal pin in the finger to hold the joint straight and act as an "internal" splint - usually for about six weeks.
After any surgery, therapy and further splinting may be needed for several months more.
How Successful is Treatment?
Although this may seem like a trivial or simple injury, a cosmetically perfect correction is not likely with any form of treatment. However, with proper therapy and effort on the part of the patient, this problem can usually be improved to a tolerable level most - that is, the end joint of the finger may not fully straighten, but it will work well enough to be used for normal activities.
Unless the injury is due to a cut on the back of the finger or there is some other associated problem, many hand surgeons believe that the final outcome and complication rate are at least as good with splinting alone compared to surgical repair. This may change as new techniques are developed to improve the results of surgery.
Surgery is a reasonable consideration if the finger remains unacceptably bent after a full trial of splinting or if splinting is not possible - for example, if a skin reaction develops beneath the splint. Surgery is only considered if the outcome of surgery is expected to be better than the outcome of treatment without surgery.
What Happens if You Don't Have Treatment?
Without any treatment, the appearance and ability to straighten the end joint of the finger will not improve. Additionally, if the injury is less than a month old, the problem may be worsened by using the finger without a protective splint of some sort.
If the injury is more than three months old and has not been treated, it is unlikely that it will get better or worse on its own. Injuries more than three months old are not likely to be improved with anything short of surgery.