Guided steroid injection for thumb carpometacarpal joint (CMCJ) osteoarthritis: A scoping review

Introduction Intra-articular steroid injection for thumb carpometacarpal joint (CMCJ) osteoarthritis (OA) is routinely offered with evidence of its short-term effectiveness only. One of the factors for reduced effectiveness could be the lack of accuracy of the intra-articular injection. Therefore, this scoping review sought to examine the accuracy of thumb CMCJ injection and examine if clinical effectiveness improves with accuracy by using image guidance. Method A literature search was undertaken using databases Medline, Emcare, AMED and CINAHL, along with Google Scholar and reference searching. All studies on adults examining accuracy of thumb CMCJ injection and image-guided injections published in English up to the end of 2023 were selected. Results 15 studies met the inclusion criteria. Cadaver studies observed lower accuracy rate of landmark-based injection particularly in presence of thumb CMCJ arthritis. Studies on patients observed an accuracy rate of around 50% with landmark-based injection. Fluoroscopy-guided injection was observed to be more accurate (near 100%) than ultrasound guidance. Clinical effectiveness of accurate intra-articular injection was observed to last from 3 months (DASH 26.7 for intra-articular vs 37.5 for extra-articular, p < 0.05 and VAS score for intra-articular 26.5 vs 39.0 for extra-articular, p < 0.05) up to 6 months (15%-10/66 patients reporting pain relief). Some studies observed accuracy of landmark-based thumb CMCJ injection increased with experience of the clinician. Conclusion Accuracy of landmark-based thumb CMCJ injection is indeterminate. However, there is lack of robust evidence to support use of image guidance to improve accuracy and clinical effectiveness of steroid injection for thumb CMCJ and warrants further research.