The Effect of Image-Guided Corticosteroid Injections on Thumb Carpometacarpal Arthritis

Background: Arthritis involving the thumb carpometacarpal (CMC) joint is common in the adult population. Initial treatment includes corticosteroid injections. Injections can be performed with image guidance to assist with placement; however, the clinical benefits are unclear. Methods: This retrospective study used Truven Health Marketscan Research Databases to identify patients from 2003 to 2014 with common International Classification of Diseases, Ninth Revision (ICD-9) codes for osteoarthritis of the CMC joint, Common Procedural Terminology (CPT) codes for image and non-image-guided injections, and codes for surgical interventions. Length of time from injection until subsequent injection(s) and/or surgery was extrapolated for identified patients. Analysis of variance and binomial logistic regression were used to compare continuous variables and calculate odds ratios, respectively. Results: We identified 62 333 patients (68% women, 32% men), average age 59.7, with common ICD-9 diagnostic codes for CMC arthritis with respective injection CPT codes. The average number of days between the first and second injection for patients treated with non-guided injection was 237.3 versus 266.7 for image-guided injections. Of the 62333 patients, 8107 went on to operative treatment. Among operative patients, the average number of days to surgery following non-guided injection was 317.7 versus 333.7 days in the image-guided group. The average cost of performing non-image-guided injections was $203 less than using ultrasound. Conclusions: Image-guided thumb CMC injections do not result in significant increases in time between injections and do not lead to a meaningful delay to surgery. Future research needs to clarify the value of image-guided CMC injections in an increasingly economically conscientious health care environment.