ANATOMIC AND CLINICAL STUDY OF A NEUROVASCULAR CAUSE OF LATERAL EPICONDYLITIS

Abstract

Because of few anatomic reports investigating the mechanism of lateral epicondylitis (tennis elbow), we performed cadaveric and clinical studies to investigate the involvement of neurovascular bundles passing through the common extensor origin. We dissected and observed under a light microscope tissue samples of neurovascular bundles passing through the common extensor tendon from 40 upper left and right limbs from cadavers. Tissue samples were prepared by hematoxylin & eosin and Weil's myelin staining. We also investigated the records of 20 patients who had been treated for lateral epicondylitis between 1991 and 2004. From cadavers, we found 60 bundles in the common extensor tendon, each 0.5 to 1.0 mm in diameter, with more bundles in the right than left limbs. Twenty-four of these bundles passed over the vertex of the lateral epicondyle of the humerus, and most of the bundles contained only one artery each. The bundles mostly originated from the radial recurrent artery, passing through the aponeurosis of the extensor corpi radialis brevis, but in some cases originated from the radial collateral artery, passing through the aponeurosis of the triceps brachii muscle. The bundles had a membranous covering when passing through the aponeurosis and produced a hiatus. Histological analysis of resected common extensor tendon tissue, 1 cm in diameter, of patients showed hyaline degeneration and fibrosis formation infiltration. Neurovascular bundles passed through the common extensor tendon in nine cases; six cases showed pulsing bleeding. After a mean follow-up of two years (6–48 months), 16 cases showed excellent results, two showed good results and two showed reliefs. Lateral epicondylitis could be caused by damage to neurovascular bundles when they pass through the common extensor origin; one cause of pain is the neurovascular bundle being compressed when passing through the common extensor tendon, secondary to the pathologic degeneration of the origin of the common extensor tendon.