Novel contrast agent tool for musculoskeletal injection procedures

Abstract Injection therapy for intra and extra-articular structures using ultrasound guidance is one of the principal medical treatments available for musculoskeletal (MSK) pain, however, these injections are inaccessible to patients who are obese or unable to wait a long time to visit a specialty center. Correct needle placement and visualization of the injectate is important to enable orthopedists and sports medicine doctors to perform these injections in obese patients under US, as well as to enable training and build confidence in general practitioners to conduct injections in their primary care offices, thus improving access. As such, the goal of this Phase 1 project is to design and develop the MSK ORBIS Contrast Device for delivery of microbubbles of air mixed in therapeutic cocktails for use as a tool to increase the accuracy and reduce the level of training needed for MSK injection procedures. If successful, the benefit, in part, would be improved access to MSK injections to obese patients and through general practitioners that can perform the injections in a primary care clinic. Other benefits potentially include more accurate injections and as such, less pain experienced by patients, less resources required to perform an injection, and more confidence in the injection procedure itself. The ORBIS device attaches to the end of a drug-filled syringe and instantaneously creates a dispersion of microbubbles during injection. In preliminary cadaver testing and benchtop testing, the ORBIS device was shown to produce microbubbles that are echogenic under ultrasound and dissipate quickly, allowing the provider to reposition the needle in cases of missed intra-articular injections. The specific aims of this proposal are as follows: 1) develop and test the MSK ORBIS device to meet design criteria including consistent microbubble concentration, optimal echogenicity and visualization, dissipation, and use with fluids of different viscosities for hip and shoulder joint injections under ultrasound guidance; 2) verify the clinical utility of the ORBIS device design through relating the benchtop data with a series of interim cadaveric studies and 3) validate the ORBIS in a study designed to evaluate the needle placement and injection accuracy of the ORBIS in cadaver shoulder and hip joints utilizing clinicians with varied experience levels. Through these aims, the clinical utility of the ORBIS will be optimized and validated for improving injection accuracy for practitioners.