Reason: possible UCL avulsion injury of R thumb History: pain LIGAMENTS: There is disruption of the distal fibers of the ulnar collateral ligament just proximal to their insertion on the base of the proximal phalanx of the thumb. Portions of the proximal fibers of the ulnar collateral ligament appear to be retracted with some fibers deep to the adductor aponeurosis . The radial collateral ligament appears intact.TENDONS: The flexor and extensor tendons appear intact.BONES: There is decreased linear signal abnormality within the ulnar aspect of the base of the proximal phalanx at the level of the insertion of the ulnar collateral ligament indicating a small minimally displaced avulsion fracture. There is bone marrow edema in the surrounding area. There is asymmetry of the MCP joint with slight ulnar subluxation of the proximal phalanx. There is a small amount of fluid within the first MCP joint.
Avulsion of the ulnar collateral ligament as well as a small Salter-Harris III/avulsion fracture of the base of the proximal phalanx of the thumb. 