Patient-related risk factors for requiring surgical intervention following a failed injection for the treatment of medial and lateral epicondylitis

To identify risk factors for failure of a therapeutic injection leading to operative management of both medial and lateral epicondylitis.A national database was used to query Medicare Standard Analytic Files from 2005-2012 for patients treated with therapeutic injections for medial or lateral epicondylitis using CPT codes for injections associated with corresponding ICD-9 diagnostic codes (726.31 and 726.32, respectively). Those who subsequently underwent surgical treatment following injection were identified. A multivariate binomial logistic regression analysis was utilized to evaluate patient-related risk factors for requiring surgery within 2 years after therapeutic injection.1,837 patients received therapeutic injections for medial epicondylitis. 52 (2.8%) required ipsilateral surgery at a mean of 429 ± 28 days post-injection. Risk factors for requiring surgical intervention included age 65, obesity, and morbid obesity. 6,561 patients received therapeutic injections for lateral epicondylitis. 201 (3.1%) required subsequent surgery at a mean of 383 ± 128 days' post-injection. Risk factors included age 65, tobacco use, diabetes mellitus and peripheral vascular disease.The incidence of surgical intervention following a failed therapeutic injection for medial or lateral epicondylitis is low (~3%). Risk factors for failing a therapeutic injection include age 65 years and obesity (BMI 30) for medial epicondylitis and age 65 years, smoking, diabetes mellitus and peripheral vascular disease for lateral epicondylitis. Patients with these identified risk factors presenting with medial or lateral epicondylitis should be cautioned that they carry a higher risk of subsequent surgical treatment.Therapeutic, III.