The Anatomy of the Posterior Interosseous Nerve in Korean: A Cadaver Dissection Study

J Korean Assoc EMG Electrodiagn Med 2005;7(1):22-26.
Published online May 10, 2005.

Abstract

Objectives: The aim of this study was to describe the most common order and location of branching patterns of the posterior interosseous nerve (PIN) in Koreans. Methods: Eight limbs from four male cadavers were dissected. The order and location of the branching from PIN were identified in relation to the bony landmarks. Bony landmarks used were lateral epicondyle of humerus and Lister’s tubercle of radius. The length of the forearm was defined as the distance from lateral epicondyle to Lister’s tubercle. The locations of the branching points were measured from lateral epicondyle to the branching point, and were expressed as percentage in comparison to the total length of the forearm. Results: Though it was variable between individual specimens, the most typical branching order of PIN from proximal to distal was ECRB, supinator, EDC, ECU, EDQ, APL, EPB, EPL and EIP. ECRB was innervated by radial nerve in two specimens (25%). Branching to the muscle was completed within 80% of forearm length. PIN was detected to run beneath the supinator muscle at a location of between 9.8% and 22.7% of the length of forearm. Conclusion: The identification of the branching order and location of PIN in relation to the bony landmark would be useful in diagnosing and evaluating the PIN injury.

Key Words: Posterior interosseous nerve, Radial nerve, Posterior interosseous syndrome