Mallet Finger

Mallet finger is an injury to the end of your finger that causes it to bend inwards towards your palm.

You will not be able to straighten the end of your finger because the tendon connecting the muscle to the finger bone is stretched or torn.

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.

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 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.

Who does it affect and why does it occur?

It can affect anyone.

Your finger will also be painful and swollen. In some cases, the tendon does not tear, but a small fragment of your finger bone breaks off where the tendon is attached.

Mallet finger is a common sports injury. It can also happen after catching your finger on something.

Symptoms
Sudden inability to fully straighten the end finger joint and the joint is held in a bent position. 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.

When to get medical help

First Aid
To relieve pain and reduce swelling, apply ice to your finger immediately and keep your hand elevated above your heart.

Go to your nearest minor injuries unit as soon as possible if you think you have a mallet finger. You’ll need to have your finger splinted.

Try to keep your hand raised until a doctor sees you. This will help reduce any swelling and pain.

If you wear a ring on the affected finger, you should remove it. The swelling might make it difficult to remove the ring later, or the ring may cut off the blood supply to your finger.

You can take an over-the-counter painkiller, such as paracetamol or ibuprofen, to help relieve the pain.

Once your finger is splinted, applying an ice pack that’s wrapped in a towel, a few times a day for 10 to 20 minutes, may also help reduce the pain and swelling.

Clinical Examination
Your doctor will ask you to try and straighten your end finger joint. You will not be able to do this, no matter how hard you try.

Investigations
An x-ray is required to see whether the tendon has pulled off a piece of bone. This will dictate treatment.

Treating mallet finger

Your finger will be put in a plastic splint, which keeps it straight, with the end joint slightly bent backwards. You’ll still be able to bend your finger at the middle joint.

The splint is taped on and must be worn day and night for 6 to 8 weeks to allow the 2 ends of the torn tendon to stay together and heal. It should only be removed for cleaning.

It’s very important that the end of your finger does not bend during the time it’s splinted because it may slow the healing and reduce the effectiveness of the treatment.

The middle joint of the finger is left free so you can continue to move it to prevent any stiffness from developing.

Surgery is only needed if you also have a broken finger, the skin is broken, or in rare cases where the mallet finger fails to heal. 

When a finger is forcibly stubbed the end finger joint (distal interphalangeal joint) bends forwards quite suddenly. This causes the tendon on the back of the finger that straightens the end joint to pull off the bone. Usually, it pulls off without a piece of bone but sometimes it can pull off a fragment.

 

Non-operative treatment
The vast majority of mallet finger injuries do not need an operation. 
If an x-ray reveals, the tendon has pulled off a large fragment of bone with it we recommend surgery. If the x-ray is all clear and shows the tendon has just been pulled away without a fragment of bone, a non-operative approach will yield satisfactory results in most patients. A splint is applied to the front of the finger (pulp side) to straighten the joint. It is worn for 6-8 weeks constantly. It can be removed for washing, but it is vital the finger is held straight at the end finger joint by a helper; otherwise, the healing tendon will become undone. The splints can be off-the-shelf stack splints, but often my patients prefer a custom-made splint by my hand therapist.

How to keep your finger clean?

You must keep your splinted finger clean and dry at all times. If the skin inside the splint gets wet it will become very sore.

It’s important to wash both your finger and the splint at least once a day, following these instructions:

  1. Keep your finger flat on a table, cut the strapping, and slide the splint off your finger.
  2. Wash and dry your finger and the splint using soap and water. Keep the end joint straight at all times by keeping your finger flat on the table. It may be easier if someone helps you to do this each day, as any movement of the end of your finger will delay the healing of the tendon and may even cause permanent damage.
  3. Slide the splint back over your fingertip, keeping your finger straight.
  4. Replace the strapping – this should cover the middle of the splint but should not cover the middle joint of your finger.

Operative treatment
When the x-ray reveals, a large bone fragment has been pulled off with the tendon, an operation may be required.
The surgery is a day case procedure usually under local anaesthetic and takes about 10 minutes. The surgery can be performed using fine wires that hold the bone fragments back in place. The wires can be inserted percutaneously through small1mm stab incisions. The wires are left in place for 4 to 6 weeks and are removed in the clinic with little discomfort.

Complications
Overall greater than 95% are happy with the result. However, complications can occur. If a splint is worn, the skin may become irritated. This requires regular washing but care to keep the finger straight whilst doing this. This may be a recurrence of the dropped finger or what is called a swan neck deformity. This deformity is the mallet appearance of the end finger joint combined with a bending backwards of the middle knuckle joint, the proximal interphalangeal joint (PIPJ). On the side profile, it has the appearance of a swan’s neck. There are surgical options to improve both these complications.

Recovery

It should take 6 to 8 weeks for your finger to heal, after which time you’ll be able to use it again. You may be advised to continue to only wear the splint at night for up to 4 more weeks.

In some cases, you may only need to see a specialist once, as a hand physiotherapist may be able to take over your care. They’ll give you exercises to do at home to help prevent your finger from becoming stiff.

Depending on your job, you may need to take some time off work. You should also avoid sports involving the hands while your injury is healing.

It may take several months for your finger to become fully functional. Redness, swelling and tenderness of the skin around the end of the finger are common for 3 or 4 months after injury but usually settle eventually.

You may be left with a small bump on the top of the joint and be unable to fully straighten the joint. Your finger may not be exactly the same as it was before the injury, but overall, it should function well.