What is a mallet finger?
A mallet finger is when the terminal extensor tendon comes away from the distal phalanx with or without a piece of bone, resulting in an inability to straighten the tip of the finger.
A mallet injury can be classified as the following:
- A bony mallet – when the tendon comes off attached to a bony fragment called an avulsion fracture.
- A tendinous mallet – where the tendon pulls off its point of bony insertion.
What are the symptoms?
Inability to straighten the tip of the finger (the distal interphalangeal joint – DIPJ)
- If you straighten the fingertip up but cannot manage to keep it straight, then it is likely that you have sustained a mallet injury.
- There can be subsequent swelling to the injured finger, most commonly overlying the DIPJ.
- A mallet injury can be painful to touch and when moving or using your hand
You will still be able to bend (flex) the joint as the flexor tendon is not interrupted in a mallet finger injury.
What Causes a mallet finger?
Mallet finger injuries usually occur when the tip of the finger is forced to bend, and most commonly occurs during impact and ball sports. Some individuals with connective tissue disorders will be at higher risk of tendinous mallet injuries.
How is a mallet finger treated?
For both types of mallet injuries, patients are placed into a splint that holds the fingertip straight or in slight hyperextension. The splint is worn strictly full time for 6 to 8 weeks. Following this period of immobilisation, the bone and tendon will be assessed for stability and healing and will then be weaned accordingly.
Mallet splints can come in a range of designs and materials and depending on your functional needs and lifestyle – your hand therapist will discuss and recommend the most appropriate splinting design for you and fabricate a custom-made splint to wear. Your hand therapist will provide exercises for the uninvolved joints, monitor the skin and oedema whilst ensuring that the splint remains a good fit to ensure optimal positioning while healing. Better outcomes are associated with early referral. If you suspect a mallet finger, see your family doctor for an x-ray and book an appointment with a hand therapist promptly.