A 27-year-old male baseball player presents with pain and swelling isolated to his right index finger DIP joint after hearing a snap during a pitch. Radiographs show a mallet finger injury with an associated avulsion fracture. The diagnosis is a mallet finger with fracture. Treatment involves splinting the DIP joint in extension for 6-10 weeks, unless the fracture is displaced more than 40% or has volar subluxation, in which case surgery may be needed. Complications can include a swan neck deformity if not treated properly.

1. Mallet Finger

2. History and Physical
• 27yo male presents after • T 98.3 P 88 BP 128/63 O2
hearing snap and having 98%
sudden pain in right index • Gen: minimal pain, NAD
finger tip after throwing a • MSK: swelling to right
fastball during semi-pro index DIP joint, which is in
baseball league. Pt has slightly flexed position. Pt
pain limited to DIP joint unable to fully extend at
of right index finger; DIP joint when isolated
denies any other injuries
• Neuro: Motor 5/5
throughout except at DIP
joint, sensory in tact.

3. Radiographs

4. Diagnosis: Mallet Finger (with fx)
Terminal extensor tendon disruption with associated avulsion fracture

5. ED Management
• For simple Mallet finger without fracture, can
splint ONLY DIP joint in extension for a
minimum of 6 weeks (usually) 10, with ortho
follow up before removal of splint
• Mallet Finger with associated avusion fx can
be treated same way unless there is frx
displacement of more than 40 % of articular
surface or w/ volar subluxation of distal
phalanx;

6. Pearls
• Occurs from forcible flexion of the extended DIP joint:
- following this injury there is unopposed flexion from the FDP;
- w/ severe flexion deformity of DIP joint in mallet finger injury a
secondary hyperextension deformity of PIP (swan neck) joint
may occur because of imbalance of the extensor mechanism;
• Be sure to get true lateral to r/o avulsion frx or frx of articular
surface;
- volar subluxation along w/ a significant intra-articular frx
(greater than 30% of joint surface) is an indication for
surgery;
• DO NOT immobilize PIP joint, and stress that finger must be
CONTINUOUSLY in hyperextension for at least 6 weeks
• Untreated, or poorly treated, may also lead to swan neck deformity.

7. More Images

8. References
• http://www.wheelessonline.com/ortho/mallet
_fractures_dup_of_496
• http://www.eorif.com/WristHand/MalletFinge
r.html
• http://www.hughston.com/hha/a_16_4_2.ht
m
• http://www.holidayparkphysicalrehab.com/ar
ticle.php?preview_aid=287