Extra-articular injections occur when the needle tip is not within the targeted joint during joint injections.
Defined by the presence of contrast outside of a joint in fluoroscopic or CT guided procedures, or the lack of direct visualization and resisted flow of intra-articular injectate during ultrasound-guided procedures.
- extra-articular injections should be identified when performing image-guided joint injections, to avoid subsequent injection of either arthrogram solution or steroid containing injectate outside of the joint
- during fluoroscopic guided procedures, straight or linear spread during injection of contrast should alert the practitioner to an extra-articular injection
- often extra-articular injections will have resistance and can be uncomfortable for the patient
- adhesive capsulitis can cause resistance and poor joint capsule distension 1
- the needle tip should be visualized throughout ultrasound-guided procedures to ensure accurate placement 2
- patient positioning can dramatically change the ease of access into the joint i.e. supinated hand during anterior glenohumeral joint injections
- the benefit of achieving and confirming an intra-articular facet joint injection is debated, as periarticular injections have been shown to have equivalent outcomes as intra-articular injections 3
- 1. Zappia M, Di Pietto F, Aliprandi A, Pozza S, De Petro P, Muda A, Sconfienza LM. Multi-modal imaging of adhesive capsulitis of the shoulder. (2016) Insights into imaging. 7 (3): 365-71. doi:10.1007/s13244-016-0491-8 - Pubmed
- 2. A. Keith Rastogi, Kirkland W. Davis, Andrew Ross, Humberto G. Rosas. Fundamentals of Joint Injection. (2016) American Journal of Roentgenology. 207 (3): 484-94. doi:10.2214/AJR.16.16243 - Pubmed
- 3. L.M. Kershen, N.C. Nacey, J.T. Patrie, M.G. Fox. Fluoroscopically Guided Facet Injections: Comparison of Intra-Articular and Periarticular Steroid and Anesthetic Injection on Immediate and Short-Term Pain Relief. (2018) American Journal of Neuroradiology. 39 (11): 2161. doi:10.3174/ajnr.A5805 - Pubmed