Fluoroscopic Sacroiliac Joint Injection: Is Oblique Angulation Really Necessary?

Abstract

Background: The conventional technique for sacroiliac (SI) joint injection involves aligning the anterior and posterior aspects of the SI joint under fluoroscopic guidance and then entering the SI joint in the most caudal aspect. Objective: We wish to highlight that there is no added advantage to aligning both the anterior and posterior joint lines of the SI joint as it is time consuming, associated with additional radiation exposure, and may make the entry into the posterior SI joint technically more difficult. Study Design: Observational study. Setting: Pain Clinic, Department of Anesthesiology. Methods: With the patient lying prone on fluoroscopy table, SI joint injection is performed with a 22 G, 10 cm spinal needle in a true anteroposterior (AP) view, where anterior and posterior SI joint spaces are seen as separate entities, where the medial joint space represents the posterior SI joint and the lateral joint space represents the anterior SI joint. The distal 1 cm of the medial joint space is entered under AP view. If the SI joint is seen as a straight line rather than 2 joint spaces in the AP view then the image intensifier of the fluoroscope was tilted cranially to elongate the image of the lower part of the posterior SI joint, thus facilitating entry into this part of the joint which was confirmed by administering 0.3 to 0.5 mL of radiopaque contrast medium. Result: Sixty SI joints of 58 patients were injected under an AP fluoroscopic view. Forty-two (70%) SI joints were seen as 2 separate medial and lateral joint spaces and were entered in distal 1 cm of the medial joint space. In 18 (30%) joints seen as a straight line rather than 2 separate spaces, the image intensifier of the fluoroscope was tilted cranially to elongate the image of the lower part of the posterior SI joint and then the SI joint was entered in its distal 1 cm. Confirmation of entry into the SI joint was confirmed by with 0.3 to 0.5 mL of radiopaque contrast medium. In 4 cases the joints did not show the correct radiopaque contrast spread (3/42 and 1/18) although the needle seemed to be in the joint space. Limitations: Small sample size. Conclusion: Aligning the anterior and posterior aspects of SI joint for fluoroscopic guided SI joint injection is not necessary for the success of the block. Key words: Sacroiliac joint, injection, anteroposterior view, oblique angulation, fluoroscopic technique

American Society of Pain and Neuroscience Best Practice (ASPN) Guideline for the Treatment of Sacroiliac Disorders

“… 28 Both Khuba et al and Chauhan found that the oblique angulation may be unnecessary and that one might enter the lower part of the posterior joint in an anterior-posterior image alone allowing for access to the joint with lower fluoroscopy times. 29 , 30 …”

“… 39 On the right side, at the S1 and S2 levels, the needles are placed at the 2:30, 4:00, and 5:30 positions. 29 At the same levels on the left, needles are placed at 9:30, 8:00, and 6:30 positions. 30 At the S3 level, needles are placed at 2:30 and 4:00 on the right and 9:30 and 8:00 on the left.…”

“…28 Both Khuba et al and Chauhan found that the oblique angulation may be unnecessary and that one might enter the lower part of the posterior joint in an anterior-posterior image alone allowing for access to the joint with lower fluoroscopy times. 29,30 Complications from SIJ injections can range from none 31 to increased pain in approximately 15-30% of patients. 28 Transient perineal anesthesia or a temporary sciatica-like syndrome post injection have also been reported.…”

Far-Contralateral Oblique (FCO) Sacroiliac Joint Injection: Description of a Novel Technique

“…However, fluoroscopy was used in a true-anteroposterior (AP) view. In the case series, sixty (60) sacroiliac joints were injected, with only four (4) joints showing incorrect contrast spread [ 17 ]. The authors concluded that aligning the anterior and posterior aspects of SI joint for fluoroscopic-guided SI joint injection was not necessary.…”