Wrist Arthrotomy Saline Load Test

Abstract

Background: Failure to recognize a potential wrist arthrotomy may lead to missed septic arthritis and devastating sequelae. The saline load test is routinely used to recognize traumatic arthrotomies of other joints; however, there are limited data optimizing this test for the wrist. The purpose of this study was to investigate and perform saline load testing to identify traumatic arthrotomies of the wrist. Methods: This was a cadaveric study of 15 wrists. Traumatic arthrotomies were created using a blunt trocar through the 3-4 portal. A 3-mL syringe with 0.1 mL markings was used to inject methylene blue dyed saline into the wrist through the 1-2 portal. Once extravasation was visible from the atherectomized site, the volume was recorded. Results: The mean (range) volume injected to identify the arthrotomy of all wrists was 1.22 mL (range, 0.1-3.1 mL). Multivariate regression demonstrated that cadaver age, laterality, and extension range of motion were not significantly associated with the injected saline volume at extravasation ( P > .05, each). Greater joint range of motion was independently associated with higher saline volume load for extravasation (odds ratio: 1.049; 95% confidence interval: 1.024-1.075; P = .003). Conclusions: We found that 2.68 and 3.02 mL of methylene blue dyed saline offered 95% and 99% sensitivity, respectively, for diagnosing traumatic wrist arthrotomy. The maximum volume of saline needed to recognize an arthrotomy was 3.1 mL. We recommend this be the minimum volume used to evaluate a traumatic wrist arthrotomy.