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Mallet finger
Understanding mallet finger, a common injury to the tendon that straightens the very tip of the finger, and why prompt assessment and splinting matters.
What is a mallet finger?
Mallet finger is an injury to the extensor tendon at the very end joint of the finger, where the tendon is torn, or pulled off with a variably sized (tiny through large) piece of bone. This means the fingertip cannot be actively straightened and droops down, though it can usually still be straightened passively with the other hand.
At a glance
What is it?
An injury to the insertion of the extensor tendon at the end joint of the finger, causing the fingertip to droop
Common symptoms
The fingertip droops and cannot be actively straightened, though it can usually be passively straightened
Who it affects
Often from ball sports, jamming the fingertip, or minor injuries such as tucking in bedsheets
Is it serious?
Needs prompt assessment and correct treatment which may simply involve splinting; untreated it can lead to a permanent droop
Treatment options
Continuous splinting for a minimum of 8 weeks in most cases, or surgery for select fracture patterns
First step
An examination and x-ray to check whether a bone fragment is involved
Causes and risk factors
- A ball striking the tip of an extended finger
- Jamming the fingertip on an object
- Minor injuries, such as tucking in bedsheets
Symptoms and how a mallet finger presents
The main sign is a fingertip that droops at the end joint and cannot be actively straightened, along with pain and swelling at the joint. There is sometimes bruising under the nail if the nail bed is also affected.
How is a mallet finger diagnosed?
Diagnosis is based on examining the droop and range of motion of the fingertip, along with an x-ray to check for an associated bone fragment or joint involvement.
If there is a fracture, the size of the smaller fragment, along with the gap between the two components is a crucial part of determining the most appropriate treatment.
Treatment options for mallet finger
Most mallet finger injuries are treated with a splint holding the end joint straight, worn continuously for a period of weeks, with the joint never allowed to bend during this time for the splint to be effective. This is done under the care of a hand therapist and does not required a surgeon.
A minority of injuries, specifically those with a large bone fragment or joint instability, may need surgery to fix the fragment or stabilise the joint.
When to see a hand surgeon
Any finger that will not straighten at the end joint after an injury should be assessed, ideally promptly, as splinting is most effective when started early.
What to expect at your appointment
At your appointment, Dr Tomlinson will discuss your x-ray, then provide treatment recommendations and a referral to a hand therapist. When we receive your doctor’s referral we are keen to know whether you have had an x-ray and whether you are wearing a splint and under the care of a hand therapist. For this reason, we recommend that you complete the questions on our registration form as soon as possible, so that we can best direct you.
Frequently Asked Questions
What is a mallet finger?
An injury to the extensor tendon at the very end joint of the finger, where the tendon is torn or pulled off with a piece of bone, meaning the fingertip cannot be actively straightened and droops down, though it can usually still be straightened passively with the other hand.
What causes it?
A ball striking the tip of an extended finger, jamming the fingertip on an object, or minor injuries such as tucking in bedsheets.
What can I do myself?
Any finger that won’t straighten at the end joint after an injury should be assessed promptly, as splinting is most effective when started early. Avoid bending the joint while waiting to be seen.
What can a hand therapist do?
Fit and manage a splint that holds the end joint straight, worn continuously for a period of weeks, with the joint never allowed to bend during this time for the splint to be effective. Many mallet finger injuries are managed this way and don’t require a surgeon.
What can a hand surgeon do?
Confirm the diagnosis on examination and x-ray, which checks for an associated bone fragment or joint involvement. A minority of injuries, specifically those with a large bone fragment or joint instability, may need surgery to fix the fragment or stabilise the joint.
What can I expect from treatment?
Most mallet fingers are treated with continuous splinting for a minimum of eight weeks. Splinting is most effective when started early, and the joint must not be allowed to bend at any point during treatment for it to work.
What happens if it's left untreated?
The fingertip droop can become permanent, and once established this is hard to correct while maintaining flexion. Prompt assessment and splinting gives the best chance of the tendon healing and the fingertip regaining function.
Related conditions and treatments
Mallet finger is a specific type of extensor tendon injury. It can occur alongside a nail bed injury if the same trauma affects the nail.