Anatomic study of posterior interosseous nerve in the arcade of Frohse.

To verify the precise anatomy of the radial tunnel, 60 cadaver elbows were dissected with special reference to 7 parameters: (1) the distance between the lateral intermuscular septum and the site of division of radial nerve into its superficial and posterior interosseous branches was 92 mm (85 to 120 mm), (2) the length of the posterior interosseous nerve from its division to the arcade of Frohse (AF) was 46 mm (35 to 65 mm), (3) the average distance between the radial head and AF was 21 mm (17 to 30 mm), (4) the average length of its branch to the extensor carpi radialis brevis muscle from its division to AF was 28 mm (20 to 45 mm), (5) the average distance of the supinator branch from its division to AF was 21 mm (15 to 28 mm), (6) the relationship between the posterior interosseous nerve and the recurrent radial artery showed several variations, and (7) the texture of AF was fibrous in 80% and was membranous in 20%. We recommend that anatomic variations should be kept in mind to avoid complications during radial tunnel surgery.