A thorough knowledge of the anatomy of the terminal branch of the posterior interosseous
nerve (PIN) and its relationship to the anterior interosseous nerve (AIN) is essential
in facilitating regional anesthetic blocks and planning surgical exposures for wrist
surgery and arthrodesis of wrist and proximal row carpectomy. This cadaveric study
focused on the anatomy and course of the PIN and its anatomical relationships at the
distal forearm. Thirty embalmed cadaver forearms were dissected using microsurgical
techniques. A structured pro forma was used to collect data. The PIN was consistently
found in the fourth extensor compartment in all specimens. The last motor branch was
given off 46.9 ± 8.4 mm (mean ± standard deviation) from the most proximal part of
the ulnar head. The AIN was found lying consistently on the anterior aspect of the
interosseous membrane, being on average 2.8 ± 0.2 mm (mean ± standard deviation) from
the PIN. This knowledge will facilitate the planning of diagnostic and therapeutic
procedures associated with the wrist.
Keywords
cadaveric wirst study - terminal posterior interosseous nerve - denervation wrist
surgery
