A Mallet finger is a finger deformity that is the result of a severed tendon in your finger leaving the last digit of your finger in a bent position with the inability to straighten it.
What is the tip of your finger made up of?
The Tendon that allows the tip of your finger to straighten, is called the Extensor Digitorum Communis. This tendon anchors below the nail bed and can be cut or ripped from the bone. The Extensor tendon is a cable that runs from the forearm into your finger and inserts onto the Distal Phalanx (Medical name of the last bone in your finger tip)
What do the Extensor tendons do?
The Extensor tendon acts like a pulley to pull the last digit backwards to straighten your finger.
In the thumb, the Extensor Pollicis Longus (EPL) is the replacement for the Digitorum Communis. Same function, different name.
How does a Mallet finger happen?
When the last digit bends forward forcefully, it may cause the tendon to spontaneously rupture, which will leave the tip of your finger hanging forward. When the force is enough, it may rip out a small piece of bone instead of tearing the tendon.
Examples are: making up the bed and jerking on the linen or when you get your finger stuck in a jersey/jacket and you try to force your finger out. This type of finger injury is common in horse riding when the rider weaves the reins through their fingers and the horse suddenly pulls forward on the reins. The most Mallet fingers entail ball sports, when the ball hits the tip of your finger and forces it to bend forward.
Causes of a Mallet finger
A specific traumatic incident is the cause that happens suddenly. You will immediately see the tip of your finger hanging and it will remain that way until you have received a diagnosis & treatment has started.
Making up the bed and jerking on the linnen may hook your finger. You might get your finger stuck in a jersey/jacket and you try to force your finger out. This type of finger injury is also common in horse riding when the rider weave their reins through their fingers, and the horse suddenly pulls forward on the reins. The most Mullet fingers entails ball sports where the ball hits the tip of your finger and forces it to bend forward.
All of these scenarios will cause the Extensor tendon to rupture.
Symptoms of a Mallet finger
A Mallet finger is not usually very disabling. Patients do however often tell me that their finger hooks on their pockets when trying to put their hands in their pockets.
Avulsion fracture (Piece of bone ripped out)
- Severe Bruising after 5 – 10 minutes
- Swelling and bleeding visible under the skin (Blue)
- Constant pain irrespective of movement
- Loss of finger movement
- No changes in sensation (normal feeling on the skin)
- Bruising (mild)
- Minimal swelling
- No pain when not moving the finger
- Unable to straighten your finger (pain is tolerable)
- No changes in sensation (normal feeling on the skin)
You may have a Mallet finger if you are able to use your opposite hand to straighten your finger but when leaving the tip of your finger it automatically falls back forward. Even when trying to keep it upright or straight, you may want to consider consulting a professional.
How bad is it?
If only the Extensor tendon is severed, a conservative 8 week program will fix the problem.
If less than 30% of the connecting surface of the bones (Distal Interphalangeal joint) is involved, and the fracture is stable meaning the bone fragments are not moved out of their normal position, the best course of treatment will be splinting by a hand therapist.
When more than 30% of the joint surface is involved or the fractured pieces are displaced from its normal alignment, you will require surgery.
We pride ourselves in our experience with regards to testing the different types of problems that can cause a Mallet finger. Our specialists are able to detect the extent of the damage. We mainly test the three components of a Mallet finger. The Extensor tendon (tendon), the integrity of the Distal Phalanx (bone) and the Distal interphalangeal joint (joint).
We develop a certain dexterity to identify a fracture but in some cases an Ultrasound or X-rays may help with making a more accurate diagnosis.
X-rays can be helpful to see if there is an avulsion fracture as well as determining the degree of separated fracture segments. This assists us to establish if the fracture is within the classification of displaced or stable. Dislocations are noticeable on X-rays, but no soft tissue (muscle or tendon injury) will show on X-rays. X-rays will be helpful to determine the type and size of the pieces of bone that has broken off.
We can determine the area of joint surface involved with X-rays to decide if surgical or conservative treatment is best suited for you.
Sonar (Diagnostic Ultrasound)
A sonar will be able to pick up bleeding or swelling around the bone itself and even ligament tears but mainly to establish the severity of the tendon injury. We often don’t refer for a sonar if the clinical presentation is obvious. It’s a nice to have, but not a necessity.
An MRI will be quite an excessive & expensive endeavour. For a Mallet finger it is a rare occurrence to request an MRI.
How we test it:
We will do a battery of tests to comprehensively screen the Extensor tendon’s ability to withstand any force. This includes active and passive testing. Isolated contraction of the Extensor Digitorum communis muscle will not extend the distal phalanx.
Why is my finger staying bent?
The Extensor tendon is not able to reconnect by itself, thus staying in this bent position. Splinting the tip of your finger in a straight position is the only way to allow the two loose ends to attach.
If a piece of bone is ripped out, it may cause the bone to heal in the wrong position, or not at all. If a separation of more than 3mm between the bone fragments are present the chances of reattachment is very poor.
A big problem we see with a Mallet finger these days:
When delaying treatment the tendon may never reattach or bone fragments will heal in an awkward position that can permanently deform your finger.
Delaying treatment for more than 2 months, might lead to a Swan Neck deformity. This is when the middle joint of the finger hyperextends and the tip of the finger stays bent. You will have considerable difficulty to use your hand, specifically to grab, hold, pull or grasp objects.
Generic braces may just make the situation worse if you don’t know what you are dealing with. Rather consult with us, to give you a clear diagnosis and prognosis.
We are usually confronted with patients that wait too long before seeking treatment. We cannot stress this enough, because this can significantly change the time to recover your finger back to its normal function.
Treatment for Mallet finger:
Splinting – A custom splint designed and tailored for your finger, to allow optimal healing and ensure the tendon or bone re-attaches.
Passive Exercises – to maintain PIPJ movement
Active exercises – to regain and strengthen the EDC muscle.
Tendon gliding techniques – to ensure the tendon moves like it should
Scar tissue mobilizations – to guide and provent andy abnormal scar tissue adhesions.
Sensory retraining – to reconditions the nerve endings in your finger.
Phases of Rehabilitation & Treatment:
1st Phase: Protection & Accurate diagnosis
Screening & our test will determine the extent of the damage and how long it will take to recover.
2nd Phase: Splinting & Stabilization
6 – 8 weeks splinting of the tip of your finger in an ideal position to immobilise the DIPJ and maintain movements in the rest of the finger, within limits.
3rd Phase: Regain Range of movement
Exercises to progressively regain movement in the Distal Interphalangeal joint, and ensuring full range of movement of the Proximal Phalangeal joint, Metacarpal Phalangeal joint.
4th Phase: Strengthening
A program to retrain the Extensor Digitorum Communis tendon’s ability to take up tension and muscle strengthening to be able to move the Distal Phalanx into extension.
5th Phase: Fine Motor skills
Dexterity in executing complex, small tasks with precision.
Tendon ruptures and stable fractures start with an 8 week immobilisation period, followed by a 4 week rehabilitation protocol. Total time to full recovery: 3 months.
Displaced fractures and surgery start with immobilisation for 4 – 6 weeks using a K-wire, thereafter splinted for 4 – 6 weeks, followed by a 4 weeks rehabilitation protocol. Total recovery time: 4 months.
Pain medication may ease some of the pain, but will do nothing to solve the problem.
Surgery of Mallet finger
K-wires are thin wires that the surgeon threads through the bones (like when making a necklace with beads) to keep the Distal Phalangeal joint stable or even inserted through the fractures fragment to join the bone.
The surgeon will insert the K-wire under general anaesthesia and remove it 4 – 6 weeks later. Getting the surgery done is only half-way to recovery. Many patients assume after 6 weeks they will have made a full recovery but a comprehensive rehabilitation program will still follow the surgery.
Mallet finger: Also Known as:
Drop finger and Baseball finger
What needs to be tested to determine the source of your hand pain
Range of Movement
Nerve tension test
Tendon gliding test