Chronic history of thumb pain. Possible MCP ulnar collateral ligament versus radial collateral ligament injury. The majority of the ulnar collateral ligament proper can be followed from the head of the metacarpal to the base of the proximal phalanx. However, there is edema-type signal within the soft tissues adjacent to the dorsal and ulnar aspect of the base of the proximal phalanx and therefore I suspect that there is a partial thickness tear of the ulnar collateral ligament proper at its attachment to the proximal phalanx. The ligament is not displaced, and there is no Stener lesion. There is intermediate signal intensity within the radial collateral ligament proper that may either reflect degeneration or a prior sprain, but I see no frank disruption of the ligament. I see no findings to suggest disruption of the accessory collateral ligaments, and the sesamoid bones appear normal. Mild osteoarthritis affects the metacarpophalangeal joint. The collateral ligaments of the interphalangeal joint of the thumb appear normal. The flexor and extensor tendons of the thumb appear normal. Bone marrow signal intensity is normal.
Mild edema along the dorsal and ulnar aspect of the base of the proximal phalanx of the thumb suggests a partial thickness tear of the ulnar collateral ligament proper. Other findings as above.