Abstract
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.
Ultrasound-guided sacroiliac joint injection in patients with established sacroiliitis: precise IA injection verified by MRI scanning does not predict clinical outcome