A mallet finger is an injury to the extensor tendon of the finger that straightens the fingertip. It results in an inability to straighten (extend) the fingertip and is commonly caused by sporting activity.
Tendons connect muscles of the forearm to bone. The extensor tendon is located at the back of the finger and attach to the small bone at the fingertip (distal phalanx). The pull of the extensor tendon straightens the fingertip.
Mallet finger can occur if the tendon comes off the bone or if it pulls a fragment of bone with it causing a fracture / avulsion.
Sometimes these injuries are not recognised immediately and treated as sprains/jammed fingers.
Sporting injuries are the most common causes. Typically, an object such as a ball hits the tip of the finger, causing it to bend forcefully and pulling off the tendon or a small fragment of bone with it.
Signs and symptoms
Diagnosis is based on examination of the finger and scans.
The fingertip will be bent and cannot straighten on its own. There will be bruising, swelling, pain and tenderness.
This is used to determine if there is an associated fracture and if the finger joint is in normal alignment.
This is usually not necessary but can be used to show detachment of the tendon from the bone if the diagnosis is uncertain.
Most mallet fingers DONT require surgery. Immediate treatment includes:
- Pain Killers.
- Temporary splint to keep the finger straight.
A splint is to be worn fulltime for 8 wks. This will be fitted/fabricated by a hand therapist. Your therapist will show you how to look after the splint and your skin.
The finger must be kept straight at all times when cleaning the finger or changing the splint. Your therapist will show you how to do this.
The splint is gradually weaned off after the 8 weeks.
Recovery and return to sport
The splint is quite thin and comfortable, and most sports and normal daily activities can be undertaken with the splint on.
Majority of patients get normal straightening and use of the finger back. Some patients may not regain full finger straightening after splint treatment – but despite this, finger use and function will be maintained.