Imaging finger joint instability with ultrasound.

Closed injuries affecting the metacarpophalangeal and interphalangeal joints and their stabilizers in the thumb and fingers occur very commonly in athletes, possibly leading to finger joint instability and long-standing or permanent disability. This article reviews the spectrum of joint injuries of the thumb and fingers that are common in the athletic population with a main focus on the ultrasound features of collateral ligament tears, palmar plate injuries, and thumb sesamoid fractures. A thorough understanding of the complex anatomy, mechanism of injury, soft tissue abnormalities, and imaging findings is critical in the diagnostic work-up of closed finger joint trauma and may help improve outcomes.