Thumb pain The proximal phalanx is adducted relative to the first metacarpal which distorts the anatomy of the first metacarpophalangeal joint and limits evaluation of the ligamentous structures. A low signal intensity structure that I believe to be the ulnar collateral ligament proper is seen extending from the dorsal aspect of the first metacarpal head to the base of the proximal phalanx. It appears thickened, but I cannot tell if this is simply due to redundancy related to patient positioning or the sequela of prior trauma. I am not convinced of a full-thickness injury to the ligament or a Stener lesion. The accessory ulnar collateral ligament likewise appears thickened and redundant which may be due to patient positioning. There is increased signal intensity within the radial collateral ligament at its attachment to the metacarpal head that may reflect chronic degeneration or sequela of prior injury. I am not convinced, however, that there is a full thickness tear of this ligament. Small cysts are seen within the underlying metacarpal head. I suspect that there is degeneration of the articular cartilage along the radial aspect of the metacarpophalangeal joint. The sesamoid bones appear intact.The ligaments of the interphalangeal joint of the thumb appear intact.The tendons of the thumb appear intact. Other than the aforementioned cysts in the neck of the first metacarpal, bone marrow signal intensity is within normal limits. Please note that this study does not include the first carpometacarpal joint.
Evaluation of the ligaments of the first metacarpophalangeal joint is limited due to abduction of the proximal phalanx relative to the first metacarpal. Focal increased signal intensity within the radial collateral ligament at its attachment to the first metacarpal head suggests chronic degeneration or perhaps sequela of prior trauma, although I am not convinced that there is a full-thickness tear of this ligament. The ulnar collateral ligament appears thickened which may reflect a prior sprain or partial-thickness tear, but this may simply be due to redundancy as a result of suboptimal positioning. We will attempt to have the patient return for repeat images with better positioning of the first MCP joint at no charge, assuming the patient can tolerate this positioning.I personally reviewed the Images and/or procedure with the Resident/Fellow and agree with this report.