Sacroiliac Distraction Test

Original Editor - Justin Gray

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Description and Purpose

The SIJ (Sacroiliac Joint) Distraction (Colloquially know as Gapping) test is used to add evidence, positive or negative, to the hypotheses of an SIJ sprain or dysfunction when used in the Laslett SIJ Cluster testing. This test stresses the anterior sacroiliac ligaments. This test has also been described as the Transverse Anterior Stress Test or the Sacroiliac Joint Stress Test.

Technique

SI Distraction Test - Vertically oriented pressure is applied to the anterior superior iliac spinous processes directed posteriorly, distracting the sacroiliac joint.

1. The patient lies supine and the examiner applies a vertically orientated, posteriorly directed force to both the anterior superior iliac spines (ASIS)

Note: Cook and Hegedus (2013) suggest applying a sustained force for 30 seconds before applying a repeated vigorous force in an attempt to reproduced the patient’s symptoms. However, Laslett (2008) does not suggest any timings or changes in force.

Because of the lack of standardisation in the technique it is quite feasible different therapists will practise this test different ways, giving rise to variability in response and lowering the inter-tester reliability. No evidence to suggest either method is preferable, therefore, more evidence needed.

2. The presumed effect is a DISTRACTION of the anterior aspect of the sacroiliac joint.

3. A test is positive if it reproduces the patient's symptoms. This indicates SIJ dysfunction or a sprain of the anterior sacroiliac ligaments

However, this test should be used in concordance within a SIJ testing cluster to ensure maximum reliability and validity when confirming hypotheses See Laslett SIJ testing cluster for further information

Sacroiliac Distraction Test video provided by Clinically Relevant

Evidence

The Diagnostic Accuracy of the Distraction test for SIJ dysfunction is described below (Original data from Cook and Hegedus (2013).

Author	Reliability	Sensitivity	Specificity	LR+	LR-	QUADAS Score (0-14) Cook and Hegedus 2013	QUADAS Score (0-14) Gunning 2013	CEBM (0-5) With qualitative J	Study Conclusion
Albert et al 2000	84%	4-14 (Average = 9)	100	NA	NA	7	7	Score = 4 Patient Spectrum 535 women fulfilling broad inclusion criteria with daily pain at gestation week 33. Reference Standard Reference standard performed on all participants Independent blind comparisons with Gold standard No gold standard used but 2 examinations performed by individual and blinded assessors Test characteristics Presented as expected but without likelihood ratios Reproducibility Method and all analyses detailed clearly. All reproducible	Test has reasonable specificity and inter-rater reliability and should be used as an assessment tool in pregnant women
Blower and Griffin 1984	63%	Not tested	89	NA	NA	5	6 - Reference standard used but minimal description. 2 studies reported in 1. Very messy study.	Score = 2 Patient Spectrum Consecutive admissions of AS patients with varying stages of progression. Reference Standard Performed on all participants Independent Blind comparisons with Gold Standard No gold standard used/ Blind testing of index test but not reference standard Test Characteristics Specificity produced but not sensitivty Reproducibility	Test has reasonable reliability and sensitivity and can be used to aid assessment of AS with LBP
Kokmeyer et al 2002	46%	Not tested	Not tested	NA	NA	NA	Abstract only	Score = 2 (Abstract only) Patient Spectrum 78 subjects with varying degress of LBP Reference Standard Unclear from abstract Independent blind comparisons with Gold standard Unclear from abstract Test characteristics Unclear from abstract Reproducibility Well described and detailed method	Test is best when used within a multitest cluster of 5 SIJ tests.
Laslett et al 2005	Not tested	60	81	3.2	0.5	12	12 - Full usage of normally available clinical data not allowed. Unclear if intermediate results reported.	Score = 5 Patient Spectrum 48 subjects with broad spectrum. Accepting range of buttock pain with/without Lumbar or lower limb symptoms. Excluded if midline pain above L5 Reference Standard Every subject received reference standard diagnosis via Fluroscopy contrast guidance of a diagnostic spinal injection. Independent blind comparisons with Gold standard Therapist and Radiologist blinded to opposite assessment. Gold standard diagnostic spinal injection used. Test characteristics Presented as expected Reproducibility Concisely and clearly detailed method and results analysis	Test best used when used within a multitest cluster (Laslett et al 2005)
Laslett and Williams 1994 (Cited Cook and Hegedus 2008)	69%	Not tested	Not tested	NA	NA	NA	Unable to obtain paper	Unable to obtain paper	NA
McCombe et al 1989	36%	Not tested	Not tested	NA	NA	NA	Abstract only	Score = 0 (Abstract only) Patient Spectrum 83 subjects but unclear in abstract how met or inclusion criteria. Unclear as to extent and type of LBP Reference Standard Unclear from abstract. Study tests inter-rater reliability of multiple tests but still unclear Independent blind comparisons with Gold standard Unclear from abstract Test characteristics Unclear from abstract Reproducibility Some description of methods and analysis in abstract but not reproducible.	NA
Ozgocmen et al 2008	Not tested	23	81	1.24	0.94	10	10 – unclear if MRI interpreted with physio findings. Withdrawls not explained. No intermediate results.	Score = 4 Patient Spectrum Unclear as to how subjects were recruited from clinic and unclear as to extent of dysfunction, except present for 3 months + Reference Standard MRI used on all tests subjects Independent blind comparisons with Gold standard Physiotherapists were blinded of MRI results while assessing subject. Test characteristics Presented as expected Reproducibility Very detailed method and analysis	Test has acceptable reliability when used in early stage sacroilitis. However, reliability, sensitivity and specificity improved when in a multi-test cluster.
Potter and Rothstein 1985	94%	Not tested	Not tested	NA	NA	NA	5 – No reference measure used. Study investigate inter-rate reliability.	Score = 3 Patient Spectrum 17 subjects with wide range of symptoms. Unilateral buttock pain, 1 year + with/without lumbar or lower limb pain or paraesthesia. Accepted pts who would normally be tested for SIJ dysfunction. Reference Standard Reference standard identical to index test but carried out on every subject by independent and blind assessor Independent blind comparisons with Gold standard No gold standard used but assessors independent and blind of each other. Test characteristics Only reliability and assessor agreement assessed Reproducibility Very detailed and specific description of method and analyses	Reliability of test is poor
Robinson et al 2007	82%	Not tested	Not tested	NA	NA	NA	10 – Reference standard not independent of index test + clinicians deprived of pain localisation on examination	Score = 3 Patient Spectrum 61 subjects with either AS, post partum pelvic pain or no pain. Reference Standard Tests performed on every subject twice but 2 random, separate, independent and blind assessors in a random order. Independent blind comparions with Gold standard Reference standard same as index test and not gold standard. Assessors were independent and blinded. Test characteristics Only reliability and assessor agreement reported. Reproducibility Well detailed methodology and analyses	Reliability of the test is moderate to good. However, test is better when performed in a multi-test cluster.
Russell et al 1981	Not tested	11	90	1.1	0.98	5	PUBmed indexed but no abstract available therefore, not obtained	Unable to obtain	Test not valid (van der Wruff cited Russell et al 1981)
Average (Mean)	65.4%	25.75	88.2	1.85	0.81	7.8	7.8	2.57	Test is acceptable used on its own, but it is best used within a cluster

Sensitivity – The possibility of a positive test resulting in someone with the pathology
Specificity – The probability of a negative test resulting in someone without the pathology
Positive Likelihood Ratio (LR+) –The ratio of a positive test result in people with the pathology to a positive test result in people without the pathology.
Negative Likelihood Ratio (LR-) – The ratio of a negative test result in people with the pathology to a negative test result in people without the pathology.
Reliability – Likelihood of results from test to be reproduced again (Expressed as percentage or as decimal)

1. A systematic review by van der Wurff et al (2000b) found that ¾ of studies included which looked at distraction found that it was not a valid test and 2/3 in van der Wurff et al (2000a) found it unreliable.
2. Stuber 2007 found only one study in a systematic review investigating Distraction Test. Stuber 2007 reported 60% sensitivity. The search excluded any papers which didn’t compare to a gold standard. This explains why only one study in Stuber 2007 was included as most of the studies from Cook and Hegedus (2013) did not utilize a gold standard comparative.
3. New evidence has come out since then suggesting the test is sufficiently and reasonably reliable and valid when used independently but is best when used in a cluster
4. Gold standard/Reference standard for SIJ dysfunction is a sacroiliac joint injection confirmed under fluoroscopy or CT-guidance using a local anesthetic solution. The injection is performed twice on 2 separate visits with the diagnosis being confirmed when the patient reports a significant change in relief from pain. Maigne et al 1998, Maigne et al (1996) and Schwarzer et al (1995) have used at least a 75 percent change in relief of pain before a response to injection is considered positive and the SIJ deemed the source of pain. However, there is some debate that injection into ligament posterior to joint rather than an intra-articular injection is actually more effective

Conclusion

Although this test does have moderate to good reliability and is reasonably accurate in diagnosing SIJ dysfunction/sprain,the evidence shows that it is best used when used within a cluster

See Also

• http://www.physio-pedia.com/Posterior_pelvic_pain_provocation_test_(aka_Thigh_Thrust_aka_Posterior_Shear)
• http://www.physio-pedia.com/Sacral_Thrust_Test
• http://www.physio-pedia.com/Gaenslen_Test