Mallet finger is an injury to the
thin tendon that straightens the end joint of a finger or thumb. Although it is
also known as “baseball finger,” this injury can happen to anyone when an
unyielding object (like a ball) strikes the tip of a finger or thumb and forces
it to bend further than it is intended to go. As a result, you are not able to
straighten the tip of your finger or thumb on your own.
With a mallet finger injury, the
fingertip droops and cannot be actively straightened.
Tendons are tissues that connect
muscles to bone. The muscles that move the fingers and thumb are located in the
forearm. Long tendons extend from these muscles through the wrist and attach to
the small bones of the fingers and thumb.
The extensor tendons on the top of
the hand straighten the fingers. The flexor tendons on the palm side of the
hand bend the fingers.
The extensor tendons straighten the
fingers and thumb through a very complex arrangement.
In a mallet injury, when an object
hits the tip of the finger or thumb, the force of the blow tears the extensor
tendon. Occasionally, a minor force such as tucking in a bed sheet will cause a
The injury may rupture the tendon or
pull the tendon away from the place where it attaches to the finger bone
(distal phalanx). In some cases, a small piece of bone is pulled away along
with the tendon. This is called an avulsion injury.
(Top) A rupture of the
extensor tendon. (Bottom) A fragment of the distal phalanx has pulled
away with the tendon.
The long, ring, and small fingers of
the dominant hand are most likely to be injured.
The finger is usually painful, swollen, and bruised. The fingertip will droop
noticeably and will straighten only if you push it up with your other hand.
Risk for Infection
It is very important to seek
immediate attention if there is blood beneath the nail or if the nail is
detached. This may be a sign of a cut in the nail bed, or that the finger bone
is broken and the wound penetrates down to the bone (open fracture). These
types of injuries put you at risk for infection.
To relieve pain and reduce swelling,
apply ice to your finger immediately and keep your hand elevated above your
A mallet finger injury requires
medical treatment to ensure the finger regains as much function as possible.
Most doctors recommend seeking treatment within a week of injury. However,
there have been cases in which treatment was delayed for as long as a month
after injury and full healing was still achieved.
After discussing your medical
history and symptoms, doctor will examine your finger or thumb. During the
examination, doctor will hold the affected finger and ask you to straighten it
on your own. This is called the mallet finger test.
During a mallet finger test, doctor
determines whether you can straighten your fingertip without assistance.
Doctorwill most likely order x-rays
of the injury. If a fragment of the distal phalanx was pulled away when the
tendon ruptured, or if there is a larger fracture of the bone, it will appear
in an x-ray. An x-ray will also show whether the injury pulled the bones of the
joint out of alignment.
This x-ray shows that a piece of the
distal phalanx bone broke away with the tendon.
Mallet finger injuries that are not
treated typically result in stiffness and deformity of the injured fingertip.
The majority of mallet finger injuries can be treated without surgery.
In children, mallet finger injuries may involve the cartilage that controls
bone growth. The doctor must carefully evaluate and treat this injury in
children, so that the finger does not become stunted or deformed.
Most mallet finger injuries are
treated with splinting. A splint holds the fingertip straight (in extension)
until it heals.
There are several types of splints
used to treat mallet finger, many of them fabricated by hand therapists.
To restore function to the finger,
the splint must be worn full time for 8 weeks. This means that it must be worn
while bathing, then carefully changed after bathing. As the splint dries, you
must keep your injured finger straight. If the fingertip droops at all, healing
is disrupted and you will need to wear the splint for a longer period of time.
When removing the splint for
cleaning and drying, the fingertip must stay in extension.
A temporary splint is applied with
two pieces of tape.
Because wearing a splint for a long
period of time can irritate the skin, your doctor may talk with you about how
to carefully check your skin for problems. Your doctor may also schedule additional
visits over the course of the 8 weeks to monitor your progress.
For 3 to 4 weeks after the initial
splinting period, you will gradually wear the splint less frequently — perhaps
only at night. Splinting treatment usually results in both acceptable function
and appearance, however, many patients may not regain full fingertip extension.
For some patients, the splinting
regimen is very difficult. In these cases, the doctor may decide to insert a
temporary pin across the fingertip joint to hold it straight for 8 weeks.
Doctor may consider surgical repair
if there is a large fracture fragment or the joint is out of line (subluxed).
In these cases, surgery is done to repair the fracture using pins to hold the
pieces of bone together while the injury heals.
is not common to treat a mallet finger surgically if bone fragments or
fractures are not present. Surgical treatment of the damaged tendon usually
requires a tendon graft — tendon tissue that is taken (harvested) from another
part of your body — or even fusing the joint straight.