Sacroiliac Joint Injection

Sacroiliac Joint Injection


Pain arising from the sacroiliac (SI) joint is common and difficult to distinguish from other causes of pain in the area of the lumbosacral junction. St joint dysfunction typically presents with localized pain in the lower back or upper buttock overlying the SI joint. Pain may be referred to the posterior thigh, but pain extending below the knee is unusual. In most cases, the etiology is unclear, and the onset is gradual over months to years. Trauma, infection, and tumor are uncommon causes of SI joint pain. The inflammatory arthropathies associated with ankylosing spondylitis, Reiter’s syndrome, and inflammatory bowel diseases are also infrequent but well-established causes of SI-related pain. Intra-articular injection of the SI joint with local anesthetic and steroid can provide short-term pain relief and assist diagnostically in establishing the source of low back pain. Radiofrequency treatments for SI-related pain have been devised but are only modestly effective in a fraction of treated patients. A long-term solution to SI-related pain is one of the needs unmet by our current armamentarium.


The SI joints are paired structures formed by the sacrum medially and the ilium of the pelvis laterally. The SI joints are the principal load-bearing structures that connect the vertebral elements of the spine with the pelvis and lower extremities. The majority of the connection between the sacrum and the ilium is in the form of a dense fibrocartilaginous connection, rather than a true synovial joint. The bulk of the true joint space is limited to the anterior portion of the apposing surfaces of the SI connection. There is a small portion of the synovial joint space that extends to the posterior- and inferior-most extent of the SI apposition, and it is from this point that access for intra-articular injection is gained. The superior extent of the SI joint lies anterior to the iliac crest, and the joint is difficult to access superior to the posterior-superior iliac spine (Fig. 8-1). The plane of the SI joint is variable from individual to individual; at the inferior extent of the joint where SI injection is carried out, the joint lies with 0 to 30 degrees of oblique angulation from the sagittal plane.

The sensory innervation to the SI joints is extensive, arising from branches of both the lumbar plexus anteriorly and the L5 dorsal ramus and S1 to S3 lateral branches posteriorly. Only the posterior aspect of the joint can be accessed with safety and ease percutaneously, and radiofrequency treatments have been devised to treat this portion of the SI joint.

Patient Selection

Patients with SI-related pain are difficult to distinguish from those with other causes of axial spinal pain, tending to report pain location over the SI joints to either side of midline near the lumbosacral junction (Fig. 8-2). Physical examination may reveal localized tenderness over the joint, and Patrick’s test (or the Flexion, ABduction, External Rotation [FABER] test) may reproduce pain in the area of the SI joint positive (Table 8-1). Degenerative change of the joint on radiography is uncommon and nonspecific; most patients with SI-related pain have normal SI joint appearance on radiography. Resolution
of pain following intra-articular injection of local anesthetic under fluoroscopic or computed tomography (CT) guidance is the best diagnostic tool available. Similar to facet joint pain, definitive diagnosis is hindered by the significant placebo effect of diagnostic injection. Treatment for SI joint pain remains inadequate and controversial. Currently, periodic intra-articular injection of steroid with local anesthetics is the most common therapy for SI joint pain but typically provides only transient relief.

Figure 8-1. Anatomy of the SI joints. The SI joints are largely stiff fibrocartilaginous connections, with the true synovial joint lying largely in the anterior aspect of the junction between the sacrum and the ilium. The true joint space extends to the inferior and posterior extent of the SI apposition, where it is accessible to injection. The plane of the posterior-inferior portion of the SI joint is variable, lying with 0 to 30 degrees of oblique angulation from the sagittal plane. The anterior portion of the joint arcs laterally. Accessing the joint is facilitated by a caudad-cephalad approach of 25 to 35 degrees to avoid the overlying posterior-superior iliac spine and iliac crest.

Level of Evidence

Quality of Evidence and Grading of Recommendation

Grade of Recommendation/Description

Benefit vs. Risk and Burdens

Methodological Quality of Supporting Evidence


RECOMMENDATION: Intra-articular SI joint may be used for symptomatic relief of SI-related pain.

2B/weak recommendation, moderate-quality evidence

Benefits closely balanced with risks and burden

II-2: Randomized controlled trials (RCTs) with important limitations (inconsistent results, methodologic flaws, indirect, or imprecise) and strong evidence from observational studies

Weak recommendation, best action may differ depending on circumstances or patients’ or societal values

RECOMMENDATION: Radiofrequency ablation: Water-cooled lateral branch nerve radiofrequency ablation of the sacral segments may be used for SI joint-related pain when previous diagnostic or therapeutic injections of the joint or lateral branch nerves have provided temporary relief. There is insufficient evidence to support the routine use of conventional (e.g., 80°C, bipolar technique) radiofrequency ablation of the SI joints.

2C/weak recommendation, low-quality or very low-quality evidence

Uncertainty in the estimates of benefits, risks, and burden; benefits, risk, and burden may be closely balanced

II-3: Observational studies or case series

Very weak recommendations; other alternatives may be equally reasonable

The available randomized controlled trials examining SI injections and radiofrequency treatment are limited. The American Pain Society (APS) Low Back Pain Guideline Panel published a report in 2009 and concluded that there was insufficient evidence to adequately evaluate the benefits of local anesthetic, corticosteroid injections, or radiofrequency treatment for the treatment of persistent nonradicular low back pain. Due to lack of available evidence, no recommendation for or against the use of SI joint injections was made by this group. Subsequently, the American Society of Anesthesiologists (ASA) Task Force on Chronic Pain Management published A 2010 Practice Guideline, offering the following recommendations: (1) “Sacroiliac joint injections may be considered for symptomatic relief of sacroiliac joint pain.”; and (2) “…water-cooled radiofrequency ablation may be used for chronic sacroiliac joint pain.”. Both groups highlight the limited evidence that is currently available to make any recommendations regarding the best means to diagnose and treat sacroiliac-related pain. In establishing the diagnosis, the features gleaned from the patient history overlap with the symptoms from a myriad of other causes for persistent nonradicular low back pain. Use of provocative maneuvers on physical examination is unreliable (Table 8-1). The gold standard for establishing the diagnosis has been pain relief with the intra-articular placement of local anesthetic, but this too is plagued by the large proportion of patients who report pain relief with the intra-articular injection of (saline) placebo. Thus, use of placebo-controlled, comparative injections is the only certain means to establish the diagnosis, and this is impractical in most clinical settings. Despite the limited evidence for long-term efficacy, the use of intra-articular SI joint injections using local anesthetic and corticosteroid remains commonplace. The use of radiofrequency treatment of the L5 dorsal ramus and the S1 to S3 lateral branches is still emerging. Detailed anatomic studies have recently appeared to guide accurate treatment and small controlled trials of water-cooled radiofrequency treatment suggest modest efficacy for this new approach.

Figure 8-2. Pattern of pain produced by SI joint dysfunction. The typical pain pattern produced by the SI joint is illustrated.

Table 8-1 Provocative Tests for SI Pain

Patrick’s or FABER (Flexion, ABduction, External Rotation) test. The knee is flexed and the lateral malleolus of the ankle placed on the contralateral patella. The knee is then slowly lowered toward the examination table in external rotation. Pain caused by hip disease (e.g., osteoarthritis of the hip) is produced by this maneuver and is reported to radiate to the groin along the inguinal ligament. During the same maneuver, the examiner presses over the flexed knee while stabilizing the contralateral side of the pelvis over the anterior-superior iliac spine. This stresses the SI joint, and report of pain over the SI joint should raise suspicion of SI joint etiology.

Gaenslen’s test. An alternate test for pain arising from the SI joint, Gaenslen’s test, is performed by placing the patient supine along the edge of the examination table. One leg is placed over the edge of the examination table and lowered toward the floor in hyperextension, while the pelvis is held stable. Pain related to the SI joint is reproduced by this maneuver.

Intra-articular Sacroiliac Joint Injection


The patient lies prone, with the head turned to one side (Fig. 8-3). The C-arm is rotated 25 to 35 degrees caudally from the axial plane to place the posterior-superior iliac spine and the iliac crest cephalad along the line of
the SI joint. The C-arm is then rotated obliquely 0 to 30 degrees until the posterior-inferior aspect of the SI joint is clearly visible (Fig. 8-4). Two features of the SI joint are important to recognize. First, the SI joint is curvilinear, often arcing somewhat laterally toward the anterior aspect (Fig. 8-5). This can lead to confusing overlying shadows of the anterior and posterior portion of the joint (Figs. 8-4 and 8-5). The second important feature is the overlying iliac crest that can block entry to the SI joint (Figs. 8-5, 8-6 and 8-7). To avoid placing a needle on the iliac crest rather than in the SI joint itself, use caudal angulation of the C-arm and limit injection to the inferior aspect of the joint.

Only gold members can continue reading. Log In or Register to continue

May 26, 2016 | Posted by in ANESTHESIA | Comments Off on Sacroiliac Joint Injection
Premium Wordpress Themes by UFO Themes