Diagnosing Sacroiliac Joint Pain

Abstract and Introduction

Abstract

The sacroiliac joint (SIJ) is a diarthrodial joint that has been implicated as a pain generator in approximately 10% to 25% of patients with mechanical low back or leg symptoms. Unique anatomic and physiologic characteristics of SIJ make it susceptible to mechanical stress and also create challenges in the diagnosis of SIJ pain. A variety of inciting causes for SIJ pain may exist, ranging from repetitive low-impact activities such as jogging to increased stress after multilevel spine fusion surgery to high-energy trauma such as in motor vehicle accidents. Similarly, wide variability exists in the clinical presentation of SIJ pain from localized pain or tenderness around the SIJ to radiating pain into the groin or even the entire lower extremity. No pathognomonic clinical history, physical examination finding, or imaging study exists that aids clinicians in making a reliable diagnosis. However, imaging combined with clinical provocative tests might help to identify patients for further investigation. Although provocative physical examination tests have not received reliable consensus, if three or more provocative tests are positive, pursuing a diagnostic SIJ injection is considered reasonable. Notable pain relief with intra-articular anesthetic injection under radiographic guidance has been shown to provide reliable evidence in the diagnosis of SIJ pain.

Introduction

The etiology of low back pain is often difficult to determine, given overlapping clinical signs and symptoms originating from an enormous number of pathophysiologic and psychosocial causes. Investigators have shown that diagnostic studies, history, and physical examination can be combined to identify some cases and ascertain that approximately 10% to 25% of time, low back pain or leg pain originates from the sacroiliac joint (SIJ). However, in the absence of trauma, tumor, or metabolic diseases directly affecting the SIJ, its role in generating low back pain is difficult to diagnose. Understanding the anatomy, function, and biomechanics of this particular joint is important to understand the pathophysiology of SIJ dysfunction.

Table 1. Describes Methods of Commonly Used Provocative Tests, Their Sensitivity, Specificity, Reliability, and Positive and Negative Predictive Values ^{8,13,16,18,37–42}
Test	Method	95% CI Sensitivity	95% CI Specificity	Reliability	Positive Predictive Value	Negative Predictive Value
FABER (flexion, abduction, external rotation) test/Patrick test/figure-four test	Patient position: Supine	57–77	40%-100%	85%-96%	81	60
	The examiner places the patient's leg so that the foot of the test leg is on the top of the knee of the opposite leg. Then, the examiner slowly pushes the knee toward the table, while stabilizing the opposite ASIS ensuring that lower back is in neutral position. A positive test is indicated by the test leg's knee remaining above the opposite straight leg with the reproduction of the patient's exact pain. Anterior hip/groin pain indicates an iliopsoas strain or hip disorder, SIJ pain indicates SIJ dysfunction while posterior hip pain suggests posterior hip impingement.	—	—	—	—	—
Gapping test/distraction test	Position: Supine with affected side close to the side of the table.	11%-60%	90–100	88%-94%	60	81
	The examiner applies pressure to both ASIS in the dorsal and lateral direction.	—	—	—	—	—
	The test is positive when the patient's exact pain is reproduced.	—	—	—	—	—
Compression test/approximation test	Position: Side posture with the affected side up and the back toward the side of the examiner. Hips are flexed to approximately 45° and knee to 90°.	0–19	90–100	74%-91%	52	82
	The examiner places folded hands over the lateral prominent iliac crest and apply a downward pressure.	—	—	—	—	—
	The test is positive when the patient's exact pain is reproduced.	—	—	—	—	—
Thigh thrust test/femoral shear test	Position: Supine with contralateral leg extended and ipsilateral leg flexed approximately 90o at hip. Then, the examiner slightly adducts the femur. The examiner's one hand cups the sacrum and the other arm and hand wraps around the flexed knee. The examiner applies a graded force through the long axis of the femur, which causes anterior to posterior shear to the SIJ on the same side.	36–88	50–100	82%–94%	58	92
	The test is positive when the patient's exact pain is reproduced.	—	—	—	—	—
Gaenslen test/pelvic torsion test	Position: Supine	21–71	26–72	82%-88%	47	76
	One leg lies over the edge of the table and other hip and knee are flexed toward the patient's chest. The examiner applies firm pressure to the flexed knee toward the chest and a counter pressure to the knee of the hanging leg toward the floor.	—	—	—	—	—
	The test is positive when the patient's exact pain is reproduced.	—	—	—	—	—
Sacral thrust test/sacral base spring test	Position: Prone.	3–63	29–100	66%-78%	56	80
	The examiner applies a pressure vertically downward on the center of the sacrum.	—	—	—	—	—
	The test is positive when the patient's exact pain is reproduced.	—	—	—	—	—
More than three positive tests	—	92%-94%	78%-87%	—	77 (95% CI: 62–92)	87 (95% CI, 74–99)

Table 1. Describes Methods of Commonly Used Provocative Tests, Their Sensitivity, Specificity, Reliability, and Positive and Negative Predictive Values ^{8,13,16,18,37–42}

Test

Method

95% CI Sensitivity

95% CI Specificity

Reliability

Positive Predictive Value

Negative Predictive Value

FABER (flexion, abduction, external rotation) test/Patrick test/figure-four test

Patient position: Supine

57–77

40%-100%

85%-96%

The examiner places the patient's leg so that the foot of the test leg is on the top of the knee of the opposite leg. Then, the examiner slowly pushes the knee toward the table, while stabilizing the opposite ASIS ensuring that lower back is in neutral position. A positive test is indicated by the test leg's knee remaining above the opposite straight leg with the reproduction of the patient's exact pain. Anterior hip/groin pain indicates an iliopsoas strain or hip disorder, SIJ pain indicates SIJ dysfunction while posterior hip pain suggests posterior hip impingement.

—

Gapping test/distraction test

Position: Supine with affected side close to the side of the table.

11%-60%

90–100

88%-94%

The examiner applies pressure to both ASIS in the dorsal and lateral direction.

—

The test is positive when the patient's exact pain is reproduced.

—

Compression test/approximation test

Position: Side posture with the affected side up and the back toward the side of the examiner. Hips are flexed to approximately 45° and knee to 90°.

0–19

90–100

74%-91%

The examiner places folded hands over the lateral prominent iliac crest and apply a downward pressure.

—

The test is positive when the patient's exact pain is reproduced.

—

Thigh thrust test/femoral shear test

Position: Supine with contralateral leg extended and ipsilateral leg flexed approximately 90o at hip. Then, the examiner slightly adducts the femur. The examiner's one hand cups the sacrum and the other arm and hand wraps around the flexed knee. The examiner applies a graded force through the long axis of the femur, which causes anterior to posterior shear to the SIJ on the same side.

36–88

50–100

82%–94%

The test is positive when the patient's exact pain is reproduced.

—

Gaenslen test/pelvic torsion test

Position: Supine

21–71

26–72

82%-88%

One leg lies over the edge of the table and other hip and knee are flexed toward the patient's chest. The examiner applies firm pressure to the flexed knee toward the chest and a counter pressure to the knee of the hanging leg toward the floor.

—

The test is positive when the patient's exact pain is reproduced.

—

Sacral thrust test/sacral base spring test

Position: Prone.

3–63

29–100

66%-78%

The examiner applies a pressure vertically downward on the center of the sacrum.

—

The test is positive when the patient's exact pain is reproduced.

—

More than three positive tests

—

92%-94%

78%-87%

—

77 (95% CI: 62–92)

87 (95% CI, 74–99)

Diagnosing Sacroiliac Joint Pain

Abstract and Introduction

Abstract

Introduction

Tables

References

Authors and Disclosures

Authors and Disclosures

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