Disability and pain after cortisone versus placebo injection for trapeziometacarpal arthrosis and de Quervain syndrome.

Abstract

This study tested the null hypothesis that type of injection (corticosteroid vs. placebo) is not a predictor of arm-specific disability as measured with the Disabilities of Arm, Shoulder and Hand questionnaire 1 to 3 months after injection of dexamethasone or placebo for treatment of trapeziometacarpal (TMC) arthrosis or de Quervain syndrome. Secondly, we tested if type of injection was a predictor of pain intensity. Thirty-six English-speaking adults with TMC arthrosis or de Quervain syndrome were randomized for a dexamethasone or a placebo injection. At time of the injection, patients completed a demographic data sheet and validated questionnaires assessing arm-specific disability, pain intensity, depressive symptoms, pain catastrophizing, and patient's health-related beliefs. At an average of 1.4 ± 0.42 months (range, 0.79-2.5 months) after the injection, patients completed questionnaires regarding arm-specific disability, pain, and treatment satisfaction. Grip and pinch strength measurements were measured at both time points. Bivariable and multivariable analyses assessed predictors of arm-specific disability and pain intensity at follow-up. Type of injection was not a predictor of arm-specific disability or pain intensity 1 to 3 months after injection. The best model both for arm-specific disability and pain intensity at follow-up included pain catastrophizing and explained 18 % and 33 % of the variability, respectively. Catastrophic thinking was a better predictor of both of arm-specific disability and pain intensity than diagnosis or type of injection (steroid vs. placebo) 1to 3 months after an injection.