Age / Sex : 45 / M

Clinical presentation : 딱밤 때리다가 3rd MCP joint 통증 발생하고 finger extension이 되지 않는다.


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Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer)

Courtesy : 이지현 (Ji Hyun Lee), 삼성서울병원 (Samsung Medical Center)

Sagittal band injury (Boxer’s knuckle)

Discussion

Findings
Discontinuity in the radial side of the sagittal band with soft tissue edema.
Mild ulnar deviation of the extensor digitorum communis tendon.

References
1. Gupta, Pushpender, et al. "High-resolution 3-T MRI of the fingers: review of anatomy and common tendon and ligament injuries." American Journal of Roentgenology 204.3 (2015): W314-W323.
2. Petchprapa, Catherine N., and Devin Vaswani. "MRI of the fingers: an update." American Journal of Roentgenology 213.3 (2019): 534-548.
3. Park, So Yoon, and Young Cheol Yoon. "US Findings of Extensor Hood Injury in Metacarpophalangeal Joint after Acute Trauma and Corresponding MRI Findings." Ultrasonography 32.2 (2013): 143-146.