What is a common injury resulting from a blow to a thrown ball at the tip of the finger?

• A. Boutonnière deformity
• B. Mallet finger
• C. Trigger finger
• D. Dupuytren's contracture

Answer: (B)

Mallet finger is a common injury that occurs when there is a rupture or avulsion of the extensor tendon at the distal phalanx due to a sudden force, such as a blow from a thrown ball. This injury typically results in the inability to extend the tip of the finger, leaving it in a flexed position. This occurs because the force from the ball can cause the tendon to pull away from its insertion at the bone, leading to an inability to properly straighten the finger.

Having an understanding of the hand’s anatomy is crucial in recognizing mallet finger. In this case, the force from a thrown object causes immediate trauma to the fingertip, resulting in the aforementioned tendon injury. Treatment usually involves immobilization to allow the tendon to heal and regain function.

The other conditions mentioned, such as boutonnière deformity, trigger finger, and Dupuytren’s contracture, involve different mechanisms and pathologies affecting the hand, but they do not typically arise directly from the impact of a thrown ball in the manner that mallet finger does.