Classic history and presentation: Doing chores around the house, hands-on activity at work, or playing a sport that includes catching a ball (eg, basketball, baseball) that causes flexion or extension of the DIP with deficit in extending the DIP.
- Age – Usually younger patients who are working / playing sports.
- Sex / gender – Various reports. Can be more common in men during the first 5 decades of life. High impact mechanisms are more common in men, whereas low impact mechanisms are more common in older women.
Pathophysiology: Disruption of the distal insertion of the terminal extensor tendon prevents extension of the DIP, leaving the finger with the unopposed pull of the flexor tendons.
Grade / classification system: Doyle's Classification (most commonly used)
I: Closed injury with or without small avulsion fracture
II: Open injury resulting from superficial laceration
III: Open injury resulting from deep soft tissue abrasion that reaches tendon
IV: Mallet fracture
- Pediatrics – distal phalanx physeal fracture
- 20%-50% of the articular surface involved
- More than 50% of the articular surface involved