Arborization of the distal posterior interosseous nerve.

Abstract

The distal posterior interosseous nerve was dissected in 41 cadaveric specimens. Intraarticular branches were tagged with radioopaque markers and verified by fluoroscopy. The nerve averaged 1.3 mm in diameter and was located on the radial side of the fourth dorsal compartment encased in thickened fascia. Six of the specimens had a branch to the distal radioulnar joint, which originated 5 cm proximal to the joint. Distally, the nerve coursed with terminal branches of the interosseous artery. Innervations were categorized according to level: radiocarpal, midcarpal, and terminal. Fourteen had innervations to all three levels, and there were radiocarpal branches in 27 specimens, midcarpal branches in 35, and terminal branches in 29. Varying combinations of innervations were seen.