The Normal Tendon and Ligament Anatomy of the Lateral Elbow: Implications for Tennis Elbow Syndrome

Abstract

Introduction: Numerous authors have studied the role that ligaments play in various elbow instability syndromes. There is no published article that has studied the role of ligaments in tennis elbow pathology. Tennis elbow patients exhibit increased pain during elbow extension. Lateral ligaments become taut in extension. Therefore, researchers decided to investigate the possibility of an anatomical link between the tendon and ligament anatomy, and how this might help to understand tennis elbow. Methods: Four fresh cadaveric elbows were dissected. Researchers examined the four tendons which comprise the common extensor origin (CEO). Researchers documented the exact footprint created by each tendon origin creates on the Humerus. Researchers also studied the exact attachments of the various named lateral ligaments both macroscopically and histologically using H and E staining. Results: Four tendons contribute to the CEO: Extensor Carpi Radialis Brevis (ECRB), Extensor Digitorum Communis (EDC), Supinator and Anconeus. All four tendons are inseparably blended together, when viewed under 2.5 x power loupe magnification. The deep fibers of the CEO are inseparably blended with the lateral collateral ligament (LCL). This was confirmed with macroscopic inspection, under 2.5 x loupe magnification, and at histological assessment. Discussion/conclusion-clinical relevance: Researchers already know that the LCL becomes taught in extension, and that the ECRB tendon becomes taut in forearm pronation. These two actions produce two shear forces at the CEO which pull in opposite directions. Researchers have found that these tendons and ligaments are inseparably blended together over a distance of 10 mm-between the lateral epicondyle and the radio capitellar joint line-researchers propose that this unique anatomy creates a specific vulnerable location whereby there exists shear forces between those two layers of collagenous tissue. Researchers propose that this explains the initiation and the perpetuation of tennis elbow lesions. It also explains the clinically observed pain during elbow extension in tennis elbow.