Mallet finger occurs due to disruption of terminal extensor tendon results in DIP joint extension lag which is called Baseball finger
Etiology
A forceful blow to the tip of the finger causes Sudden flexion over the DIP
Hyperextension injuries with fracture of the dorsal lip of dorsal phalanx
Classification of Mallet finger
| Type | Features |
|---|---|
| Type 1 | Most common Close blunt trauma with loss of tendon continuity with/ without small avulsion fracture |
| Type 2 | Laceration at or proximal to DIP and loss of tendon continuity |
| Type 3 | Deep avulsion with loss of skin, subcutaneous cover, and tendon substances |
| Type 4A | Transphyseal fracture in children |
| Type 4B | Hyperflexion injury with fracture of the articular surface (20%-50%) |
| Type 4C | Hyperflexion injury with fracture of the articular surface (>50%) with early or late volar subluxation of the distal phalanx |
Treatment Options according to classification
Type 1
Continuous DIP extension splint (6-8 weeks), then night splinting for (2-6 weeks) additional
Volar or dorsal splint
Hyperextension of the distal IP joint avoided because it causes skin balancing and breakdown
Type 2
Close reduction after appropriate wound care
Splint management may be difficult due to wounds so direct repair of extensor tendon with K-Wire fixation of DIP Joint in full extension
Type 3
Require soft tissue coverage and pinning of DIP joint
Possible arthrodesis
Child Mallet finger (Seymour fracture)
Closed reduction of DIP in slight extension (4 weeks)
If close reduction cannot be obtained, OR with K-wire fixation for epiphyseal fragment
Type 4B/4C
Operative treatment is associated with numerous complications
- Infections
- Nail deformity
- Tender pulp scan
- Loss of reduction and fixation
Nonoperative extension splint
For Fracture: > 1/3rd of the articular surface. OR using pull-out wire + Transarticular K-wire in extension is advised
Chronic mallet finger: Painful condition so better go for arthrodesis
