Radial Collateral Ligament of the Elbow

ateral epicondylitis, or tennis elbow, is the most common cause of lateral elbow pain and can be a major cause of symptoms and debilitation.1 The term “lateral epicondylitis” is a misnomer, in that the abnormality causing tennis elbow is degeneration and a possible tear of the common extensor tendon (CET) at or near its humeral origin.2 Histologic studies have shown that there is no significant inflammation associated with chronic tennis elbow; therefore, the term “tendinitis” is not appropriate.3 Moreover, hyperemia on color and power Doppler imaging has been shown to represent neovascularity and not inflammation.3 Sonography and magnetic resonance imaging (MRI) may be used to confirm clinically suspected tennis elbow and to exclude other causes of lateral elbow pain.1,2 Such imaging can reveal the extent of the tendon abnormality and also show a coexisting abnormality of the radial collateral ligament (RCL), which lies immediately Jon A. Jacobson, MD, Mary M. Chiavaras, MD, PhD, Jason Michael Lawton, Brian Downie, PA-C, Corrie M. Yablon, MD, Jeffrey Lawton, MD