Injection of Dexamethasone Versus Placebo for Lateral Elbow Pain: A Prospective, Double-Blind, Randomized Clinical Trial

Abstract

We tested the hypothesis that there is no difference in disability, pain, and grip strength 1 and 6 months after corticosteroid and lidocaine injection compared with lidocaine injection alone (placebo). Sixty-four patients were randomly assigned to dexamethasone (n = 31) or placebo (n = 33) injection. At enrollment, disability (Disabilities of the Arm, Shoulder, and Hand [DASH] questionnaire), pain on a visual analog scale, grip strength, depression (the Center for Epidemiologic Studies Depression Scale; CESD), and ineffective coping skills (the Pain Catastrophizing Scale; PCS) were comparable between treatment groups. At 1 and 6 months, DASH, pain, and grip strength measures were repeated. Univariate and multivariate analyses were used to determine predictors of disability. Analysis was by intention to treat. One month after injection, DASH scores averaged 24 versus 27 points (dexamethasone vs placebo), pain 3.7 versus 4.3 cm, and grip strength 83% versus 87%. At 6 months, DASH scores averaged 18 versus 13 points, pain 2.4 versus 1.7 cm, and grip strength 98% versus 97%. CESD and PCS scores correlated with disability as measured by the DASH questionnaire. The best multivariate models included CESD at 1 month and PCS scores at 6 months and explained the majority of variability in DASH scores. Corticosteroid injection did not affect the apparently self-limited course of lateral elbow pain. In secondary analyses in a subset of patients, perceived disability associated with lateral elbow pain correlated with depression and ineffective coping skills. Therapeutic I.