Magnetic resonance imaging of normal anatomy and injury patterns in the trapeziometacarpal joint ligaments.

OBJECTIVE: This study aimed to explore the anatomy and injury patterns of trapeziometacarpal (TMC) joint ligaments by using magnetic resonance imaging (MRI). MATERIALS AND METHODS: In total, 32 asymptomatic healthy volunteers (16 women, 16 men; mean age, 34.5 ± 5.4 years) and 18 patients (12 women, 6 men; mean age, 43.6 ± 10.4 years) were recruited between January 2019 and November 2024. All participants underwent MRI of the TMC joint using T1-weighted imaging and proton density-weighted imaging with fat suppression. Two musculoskeletal radiologists independently analyzed the MRI features of the TMC joint ligaments in volunteers and patients. RESULTS: In asymptomatic volunteers, the normal anterior oblique ligament (AOL), dorsal radial ligament (DRL), and posterior oblique ligament appeared as slender, low-signal fibrous structures on MRI, whereas the normal intermetacarpal ligament exhibited a striated signal. The AOL was significantly thinner in women than in men, and there were no significant sex differences for other ligaments. Ligament injuries were characterized by changes in MRI signal: Sprains showed high-signal alterations, partial tears displayed thickening and partially discontinuous fibers with disrupted signals, and complete ruptures were characterized by ligament retraction and fluid-filled gaps. Among the ligaments, the AOL was most susceptible to injury, followed by the DRL. CONCLUSION: Magnetic resonance imaging is an accurate method for assessing the anatomy and pathological conditions of the TMC joint ligaments, thus aiding in the accurate diagnosis and management of ligament injuries.