Fingerbreadths Rule in Determining the Safe Zone of the Radial Nerve and Posterior Interosseous Nerve for a Lateral Elbow Approach: An Anatomic Study. (February 2019)

• Record Type: Journal Article
• Authors: Simone, Juan P.; Streubel, Philipp N.; Sánchez-Sotelo, Joaquín; Steinmann, Scott P.; Adams, Julie E.
• Is Part Of: Journal of the AAOS. Volume 3:Number 2(2019)
• Publication Date: 2019-02
• Subjects: Orthopedic surgery -- Periodicals; 617.4705
• DOI: 10.5435/JAAOSGlobal-D-19-00005
• Languages: English
• ISSNs: 2474-7661

Abstract

Abstract : Introduction: The purpose of this study was to investigate whether a safe zone rule could be applied to prevent iatrogenic injuries to the radial nerve (RN); and determine whether there is a relationship between the diameter of the radial head and capitellum and the distance of the posterior interosseous nerve (PIN) to the radiocapitellar joint. Methods: Ten fresh-frozen cadaveric specimens were used to measure the distances between the RN and the lateral epicondyle; the PIN and the radiocapitellar joint; the lateral epicondyle and the PIN as it crossed the ulnohumeral joint; the diameter of the radial head; the width of the capitellum; and the fingerbreadths of the specimens. Results: Four fingerbreadths determined a safe zone between the lateral epicondyle and the RN proximally at the point at which it pierced the intermuscular septum and the mid-lateral portion of the humeral shaft. Two fingerbreadths provided a safe zone for the PIN from the radiocapitellar joint to the midpoint of the axis of the radius only with the forearm in pronation. Conclusion: A four-finger rule, two-finger rule, and radial head diameter or capitellum size may predict a safe zone for the RN and PIN except for the segment of the nerve where it crosses the anterior cortex of either the humerus or radius. Level of Evidence: Preclinical cadaveric study