A. Antero-posterior view of Guyon canal/ulnar tunnel (white arrow) and pisohamate hiatus (black arrow). TCL, transverse carpal ligament ; VCL, volar carpal ligament; FCU, flexor carpi ulnaris; PB, palmaris brevis; ODM, opponens digiti minimi; ADM, abductor digiti minimi; FDMB, flexor digiti minimi brevis; F, finger flexor tendons; N, ulnar nerve; A, ulnar artery; H, hamate.
B. Axial view of pisohamate hiatus. (Uriburu et al., 1976(13)) Ulnar nerve and artery are divided into superficial and deep branches by the fibrous arch of the hypothenar muscles.
C. Axial view of Guyon canal/ulnar tunnel. (Guyon, 1861(1,2)) ACL, anterior carpal ligament.