Mallet finger :Injury to the extensor tendon at the DIP joint

Injury to the extensor tendon at the DIP joint is also known as :

• A) boutonnière deformity
• B) jersey finger
• C) mallet finger
• D) swan necking
• E) “jammed” finger

The answer is (C).

Injury to the extensor tendon at the DIP joint is also known as Mallet Finger or Dropped Finger. The condition is the most common closed tendon injury of the finger.

Mallet finger usually is caused by an object (e.g., a ball ;baseball finger) striking the finger, creating a forced flexion of an extended DIP. The extensor tendon may be strained, partially torn, or completely ruptured or separated by a distal phalanx avulsion fracture. Those affected with mallet finger complain of pain at the dorsal DIP joint; inability to actively extend the joint; and, often, with a characteristic flexion deformity. It is critical to isolate the DIP joint during the evaluation to ensure extension is from the extensor tendon and not the central slip. The absence of full passive extension may indicate bony or soft tissue entrapment requiring surgical intervention.