When Lateral Epicondylitis Is Not Lateral Epicondylitis: Analysis of the Risk Factors for the Misdiagnosis of Lateral Elbow Pain.

Abstract

Lateral elbow pain, often attributed to lateral epicondylitis, presents diagnostic complexities. Lateral epicondylitis, or tennis elbow, is the most frequent cause of lateral elbow pain, but a differential diagnosis among all the potential causes of lateral elbow pain is not easy. To evaluate the rate of misdiagnoses in patients previously diagnosed with lateral epicondylitis, identify at-risk patient profiles, and determine sensitive clinical tests for a misdiagnosis. Case series; Level of evidence, 4. A prospective analysis was conducted on 189 consecutive patients with a previous diagnosis of lateral epicondylitis and failed nonoperative treatment. According to medical history and a physical examination, patients were preliminarily classified into the typical or atypical lateral epicondylitis group. Atypical epicondylitis was defined as one of the following: atypical lateral pain location, history of trauma, limited range of motion (ROM), elbow swelling, negative Cozen test finding, and physical examination findings suggesting a misdiagnosis. Patients in the atypical group were further investigated for a potential lateral epicondylitis misdiagnosis using magnetic resonance imaging, computed tomography, and/or analysis of intraoperative samples according to suspected underlying abnormalities. Univariate and logistic regression analyses were conducted to assess the risk of a misdiagnosis. A standardized diagnostic analysis was performed to evaluate the clinical tests used during the physical examination to identify misdiagnosed patients. A misdiagnosis occurred in 21 of 189 (11%) patients. The most common misdiagnoses were posterolateral elbow instability in 6 patients; radial nerve compression and inflammatory osteoarthritis in 3 patients each; and osteochondritis dissecans, posterolateral plica, and primary osteoarthritis in 2 patients each. The variables associated with a misdiagnosis were young age (≤30 years; odds ratio [OR], 66.90; <i>P</i> < .001), history of trauma (OR, 17.85; <i>P</i> = .0027), history of a limitation of ROM and/or mechanical symptoms (OR, 16.68; <i>P</i> = .0278), history of elbow swelling (OR, 14.32; <i>P</i> = .0032), and number of corticosteroid injections (OR, 2.00; <i>P</i> = .0007). Atypical lateral pain location highly predicted a misdiagnosis, with a sensitivity of 90.5%. A misdiagnosis can occur in patients affected by longstanding lateral elbow pain. Young patients and patients with a history of elbow trauma, a limitation of ROM, swelling, corticosteroid injections, and atypical lateral pain should be highly suspected for a misdiagnosis.