Mallet Finger, Baseball finger, or Hammer finger are all common names for this injury. It is an injury to the terminal extensor tendon at the distal interphalangeal joint.1
This is typically the result of an axial loading injury with the finger or thumb in extension forcing the joint into flexion and may be accompanied with an intra-articular avulsion fracture.2 This may also commonly result from a dorsal laceration.
Figure 2. Typical appearance of mallet finger of 2nd digit (photo credit)
In the ED, acute mallet finger injuries are evaluated with plain radiographs.
The preferred management for mallet finger with and without avulsion fracture is non-operative treatment.1-3
Splint the DIP in neutral while maintaining free movement of the PIP joint. Volar splinting is preferred over dorsal splinting. Avoid hyperextension. See more examples of good examples of DIP splinting.
Discharge with an extension splint (ensure free PIP movement) and follow up with primary care or sports medicine physician. The splint should be worn for at least 6 weeks. Conservatively this means 6 weeks of 24 hours splinting followed by 2-6 weeks of nighttime splinting depending on symptoms.1,4