Figure 18.

Ulnocarpal impaction. (A) Coronal proton density fat-suppressed MR image shows type 1a paracentral region tear (solid arrow) associated with subchondral cystic changes on the ulnar proximal aspect of the lunate (block arrow) consistent with ulnocarpal impaction. Mild ulnar positive variance is present; (B) coronal proton density fat-suppressed MR image of another patient also shows type 1a tear at the paracentral region of the TFCC (solid arrowhead) associated with subchondral cystic changes on the ulnar proximal aspect of the lunate (block arrowhead) with mild overlying cartilage irregularity. Features consistent with ulnocarpal impaction. TFCC, triangular fibrocartilage complex.