
Am Fam Physician. 2022;105(3):239-245
Patient information: See related handout on sacroiliac joint dysfunction and back pain, written by the authors of this article.
Author disclosure: No relevant financial relationships.
Sacroiliac (SI) joint dysfunction is a common cause of low back pain and accurate diagnosis can be challenging. A complete history and physical examination are critical in differentiating other diagnoses that may have similar signs and symptoms. Positive responses to at least three physical provocation tests suggest SI joint dysfunction, and local anesthetic SI joint blocks can also be useful for confirming the SI joint as the source of pain. Conservative treatment consists of a multimodal program combining patient education, pelvic girdle stabilization with focused stretching, and manipulative therapy. These programs can be performed by physical therapists or clinicians trained in manipulative therapy. Pelvic belts may be beneficial in affected postpartum patients. Patients with symptoms that do not improve with conservative management may benefit from interventional treatment options including intra-articular corticosteroid injections, cooled radiofrequency ablation, or SI joint fusion.
The prevalence of sacroiliac (SI) joint dysfunction is approximately 25% in adult patients with chronic low back pain.1 Pain can be unilateral or bilateral but usually not midline.2 Women are more likely to present with SI joint dysfunction than men.3 The SI joint in women is more mobile compared with the SI joint in men, resulting in larger stress, load, and pelvic ligament strain.4 SI joint dysfunction is common in pregnant and postpartum patients.5
Clinical recommendation | Evidence rating | Comments |
---|---|---|
Use the clinical decision rule of at least three out of five positive provocation tests (Gaenslen, thigh thrust, distraction, compression, and sacral thrust) to assist in diagnosing SI joint dysfunction.6,17 | B | Consistent results from prospective and blinded validity trials |
Confirmation of SI joint pain can be made by an image-guided anesthetic block to the SI joint.1,20 | B | Systematic reviews to identify diagnostic accuracy of SI joint injections |
Nonsteroidal anti-inflammatory drugs may be beneficial as part of a multimodal treatment approach.25,26 | C | Expert opinion and accepted practice standards |
Physical therapy exercise programs, SI joint manipulation, or a combination of both should be considered as first-line treatment options.11,14,15,21–24,27–29 | B | Consistent results from randomized controlled trials and practice recommendations from in-depth reviews |
Etiology and Differential Diagnosis
The SI joint serves as a shock absorber and transfers vertical loads from the lumbar spine to the lower extremities during bending movements. The etiology of SI joint dysfunction is not well understood. The SI joint may be the primary source of pain, or dysfunction at the joint or surrounding structures may affect the joint’s load transfer function and produce a painful stimulus.6
SI joint dysfunction can be associated with osteoarthritis or inflammatory conditions such as ankylosing spondylitis, posttraumatic arthritis, and other spondyloarthropathies.7 Similarly, mechanical faults at the pubic symphysis or SI joint can result in pelvic asymmetry or joint instability. Nonoptimal load transfer is seen in patients with SI joint stiffness (hypomobility) and patients with insufficient pelvic girdle stability (hypermobility).8 Table 1 presents the differential diagnoses of conditions with similar or overlapping signs and symptoms of SI joint dysfunction.9–11

Differential diagnosis | Clinical presentation |
---|---|
Femoral acetabular impingement | Pain with activity or prolonged sitting, joint locking or clicking |
Fractures (secondary to trauma, osteoporosis) | History and imaging |
Infection | Fever, malaise, intractable pain |
Ischiofemoral impingement | Gluteal or hip pain, hip snapping, shortened stride |
Lumbar disc herniation | Numbness or tingling in the legs or feet, lower extremity weakness, radiating pain, bowel or bladder changes |
Lumbar facet syndrome | Older age, paraspinal muscle tenderness, pain with backward bending |
Piriformis syndrome | Sitting intolerance, radiating pain along the posterior of one or both legs |
Pudendal nerve irritation | Perineal or scrotal pain, sitting intolerance |
Spondyloarthropathies | Positive findings on laboratory tests, diagnostic imaging |
Tumor | Focal bone pain, pathologic fractures |
History and Physical Examination
Differentiating SI joint dysfunction from other diagnoses presenting with low back pain requires a complete history and physical examination of the spine, pelvic girdle, and hips as well as a review of other systems to rule out red flags such as history of trauma, unexplained weight loss, fever, bowel and bladder changes, cancer, and night pain.6,12,13
Patients with SI joint dysfunction may present with pain that is localized to the area at or just inferomedial to the posterior superior iliac spine as demonstrated in a Fortin finger test (Figure 1) or along the gluteal area, lateral hip, lower extremities, and groin.2,12 Potential aggravating factors and activities that may exacerbate pain from SI joint dysfunction are described in Table 2.3,12


Ascending or descending stairs |
Jogging uphill |
Landing after jumping |
Lying on the affected side |
Prolonged sitting in a car |
Prolonged standing |
Shifting weight to the affected side |
Turning in bed |
SI joint dysfunction may be attributed to a variety of causes.12 Traumatic onset commonly occurs with heavy lifting, a fall onto the buttocks, and motor vehicle collisions. A more insidious onset can be caused by recreational activities with repeated weight bearing and shear or torsional forces experienced during sports such as football, gymnastics, and golfing.
A physical examination should include gait analysis (i.e., reporting of pain with walking, shortened stride length, antalgic gait), range of motion, provocation testing, strength, flexibility, and palpation assessments (Table 3).2,3,12,14–16 Lower extremity neurologic screening (i.e., reflexes, sensation, strength, straight leg raise) is helpful when considering differential diagnoses.

Component | Findings or physical examination response |
---|---|
Observation | Asymmetric iliac crest height |
Asymmetric weight-bearing when standing | |
Gait | Painful catching or increased pain ipsilaterally during stance phase |
Decreased hip extension resulting in shortened contralateral stride length | |
Provocation tests | Three of five positive tests suggest sacroiliac joint dysfunction (Figures 2 through 6) |
Strength testing | Gluteus medius weakness |
Flexibility | Iliopsoas tightness |
Piriformis tightness | |
Hamstring tightness with gluteal weakness | |
Palpation | Reported pain at or inferomedial to the posterior superior iliac spine |
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