Forearm supination and the posterior interosseous nerve: a cadaveric study with surgical implications

Introduction: The lateral and anterior approaches to the proximal radius are often used in the surgical treatment of radius shaft fractures. Posterior interosseous nerve injury is among the complications of these procedures. This nerve is also known as the deep branch of the radial nerve. It innervates several muscles of the posterior compartment of the forearm. The posterior interosseous nerve runs close to the radiocapitellar joint and pierces the supinator muscle beneath the Frohse’s arcade. There is great debate in the literature whether to supine or to pronate the forearm in order to avoid iatrogenic injuries of this nerve. The present work aims to measure the distance between the posterior interosseous nerve and the distal biceps tendon during forearm pronation or supination. Material and Methods: A sample of 30 cadavers (15 male and 15 female) were dissected and the posterior interosseous nerve was traced to the Frohse’s arcade. The distance between its point of entrance and the distal biceps tendon, the radial head and the radiocapitellar joint were measured during forearm pronation and supination with the aid of a digital caliper. Statistical analysis was performed with the IBM SPSS 23 software, p < 0.05 was considered significant. Results: It was observed that the distance increased significantly (p < 0.05) during supination. Conclusions: Maximum supination of the forearm may be an excellent maneuver to increase the distance between the posterior interosseous nerve and several anatomical landmarks thus helping to avoid damage during the Henry’s and Kocher’s approaches to the elbow.