This is when the finger tip is forcefully bent forwards. The tip then doesn't straighten, because the extensor tendon to the finger has become detached. This may or may not include a small bony fracture (avulsion).
Mallet finger can also occur without direct force to the tip, which also is not uncommon.
Mallet finger injuries are often treated effectively by splinting the tip of the finger straight for 6-8 weeks. Splinting is most comfortably achieved with a small custom made plastic splint which a hand therapist can make. These splints are safe to wear for most work duties and during game play (when covered with firm tape).
It is always recommended that an x-ray is taken to see whether there is a bony fracture. When there is a fracture present, which often occurs in ball v's tip Mallet injuries- the splinting time frames may be shorter.
Following the period of immobilisation, movements & use of the finger are gradually introduced. We can teach taping techniques for work and sport to support the tendon in this phase. The tendon injury can remain weak for some time, and it is therefore important that movement and use is introduced safely and gradually.
If left untreated the Mallet finger may develop what we call a fixed flexion deformity- meaning that the finger permanently becomes stuck in a bent position and can no longer be straightened. The inability to control a finger like that can be annoying; many men complain it gets in the way when reaching to get their wallet out of their pocket. And a permanently bent tip can become a safety risk- as it is not so easy to get it out of harms way.
The art and science of hand therapy really come into play treating Mallet finger injuries!