The anatomy of the posterior interosseous nerve as a graft

Thirty upper limbs from skeletally mature embalmed cadavers were studied to determine the anatomic reliability of the posterior interosseous nerve as a donor nerve graft. The posterior interosseous nerve branches 0.43 +/- 0.5 2 cm from the distal edge of the superficial head of the supinator and 8 +/ - 1.6 cm from the lateral epicondyle form a common leash. There are 6 branc hes, which are arranged from the ulnar to the radial side at their origin f rom this leash. The first and second branches supply the extensor digitorum communis, the third branch supplies the extensor carpi ulnaris, the fourth branch supplies the extensor digiti minimi, and the fifth branch arises fr om the undersurface of the common leash and divides into 2 subbranches (med ial and lateral) 10.1 +/- 3.2 cm distal to the lateral epicondyle and 12.8 +/- 2.2 cm proximal to Lister's tubercle. These 2 subbranches make an inver ted V shape around the extensor pollicis longus. The medial branch supplies the extensor pollicis longus and extensor indicis proprius. The lateral br anch supplies the extensor pollicis longus and extensor pollicis brevis and ends at the wrist capsule. At a mean distance of 8.1 +/- 1.2 cm proximal t o Lister's tubercle the lateral subbranch gives off its last muscular branc h to the extensor pollicis longus and becomes a pure sensory terminus. As t he terminal part of the lateral subbranch approaches the wrist capsule it e xpands at a mean distance of 1.9 +/- 0.5 cm proximal to Lister's tubercle. The sixth branch arises from the radial side of the common leash and divide s into 3 subbranches. The first subbranch supplies the abductor pollicis lo ngus and extensor pollicis brevis, the second supplies the abductor pollici s longus, and the third supplies the superficial head of the supinator. Thi s study showed that the mean length obtainable for harvesting the lateral s ubbranch of the fifth branch of the posterior interosseous nerve is 6.2 +/- 0.7 cm, which represents the length of the nerve between the last muscular branch to the extensor pollicis longus to the point at which the nerve exp ands. (J Hand Surg 2000;25A;930-935. Copyright (C) 2000 by the American Soc iety for Surgery of the Hand.).