The Sweater Finger Sign is indicative of what condition?

The Sweater Finger Sign is characteristic of a ruptured flexor digitorum profundus tendon. This condition occurs when the tendon responsible for flexing the distal phalanx of a finger is torn, typically due to a forceful impact or trauma. The sign is named for its presentation, in which the affected finger cannot flex at the fingertip while the other fingers can still perform the motion normally, resembling the way a sweater might hang on a finger.

In contrast, De-Quervain's tenosynovitis involves inflammation of the tendons on the thumb side of the wrist, and its symptoms include pain and swelling along the radial side of the wrist. Carpal tunnel syndrome affects the median nerve at the wrist, leading to numbness and tingling in the thumb, index, and middle fingers, along with potential weakness. Ulnar nerve palsy typically affects the fourth and fifth fingers, producing symptoms such as numbness and an inability to spread the fingers apart.

Thus, the Sweater Finger Sign specifically points to the disruption of the flexor tendon, making it the clear indicator for a ruptured flexor digitorum profundus tendon.