Success Rate of Intra-articular Sacroiliac Joint Injection: Fluoroscopy vs Ultrasound Guidance—A Cadaveric Study

BACKGROUND: Given the unacceptably high miss rates of non-image-guided injections into the sacroiliac joint, either fluoroscopy or ultrasound is recommended for guidance. The real success rate of both techniques was assessed by cadaver dissection. METHODS: Twenty bodies donated to science (40 joints: 15 female and 5 male) were investigated bilaterally. Fluoroscopy and a lower ultrasound-guided approach were performed in 10 bodies each. Conditions during puncture, the subjective feeling of the needle being intra-articular, and, for fluoroscopic guidance, the intra-articular spread of the contrast were assessed. First, 0.5 cc of Iopamidol was injected, followed by 2 mL of red-colored latex. The spread was investigated by dissection via anterior opening of the sacroiliac joint and the dorsal ligaments. RESULTS: Ultrasound guidance was used in 1/20 (5%, 95% CI = 0.9-23.6%) intra-articular injections. In 19/20 (95%, 95% CI = 0.9-23.6%) cases, latex spread in the interosseous sacroiliac ligament was used. Conditions of structural visibility were classified as good in 11/20 (55%, 95% CI = 34.2-74.2%) cases, puncture condition as good in 16/20 (80%, 95% CI = 58.4-91.9%) cases, and subjective feeling of the needle being intra-articular was present in 10/20 (50%, 95% CI = 34.2-74.2%) cases. Fluoroscopy showed an intra-articular injection in 10/20 (50%, 95% CI = 34.2-74.2%) cases. The structure visibility in fluoroscopy was good in 9/20 (45%, 95% CI = 25.8-65.8%), puncture conditions good in 8/20 (40%, 95% CI = 21.9-61.3%), intra-articular contrast spread visible in 10/20 (50%, 95% CI = 34.2-74.2%), and subjective feeling of being intra-articular was present in 17/20 (85%, 95% CI = 64.0-94.8%) cases. CONCLUSIONS: Fluoroscopy clearly showed a higher success rate of intra-articular sacroiliac joint injection.