Can left hip pain cause a positive Straight Leg Raise (SLR) test?

Can Left Hip Pain Cause a Positive Straight Leg Raise Test?

No, left hip pain alone does not typically cause a true positive Straight Leg Raise (SLR) test, as a genuine positive SLR test specifically indicates sciatic nerve root irritation or compression, not hip pathology. 1, 2

Understanding the SLR Test and Its Interpretation

• A positive SLR test is defined as reproduction of the patient's sciatica (radiating leg pain) when the leg is raised between 30-70 degrees with the knee extended, with high sensitivity (91%) but modest specificity (26%) for diagnosing lumbar disc herniation 1
• The test works by placing tension on the sciatic nerve and nerve roots, not by stressing hip structures 1, 2
• A true positive SLR test reproduces the patient's radiating leg pain, not just hip pain or back pain 3
• Only 7 out of 31 clinicians in one survey correctly recognized that reproduction of leg pain is what indicates a positive SLR test, showing common misinterpretation 3

Hip Pathology vs. Radicular Pain

• Hip-related pain requires a comprehensive clinical examination that includes screening for other conditions that might present with similar symptoms (e.g., spine pathology) 4
• The FADIR test (flexion, adduction, internal rotation) is the recommended clinical test for screening hip-related pain, not the SLR test 4
• Diagnostic imaging demonstrates only small to moderate shifts in post-test probability for hip pathology and should never be used in isolation 4
• Hip conditions may cause pain that mimics radicular symptoms, but would not create a true positive SLR test 4

Differentiating Hip from Lumbar Pathology

• When hip pain coexists with low back, pelvic, or knee pathology, MRI is the best next test after radiography to screen the hip for significant pathology 4
• Image-guided anesthetic injections can be used diagnostically to determine if pain is related to the hip joint rather than lumbar pathology 4
• Ultrasound is useful for examining soft tissue structures around the hip for specific diagnoses such as trochanteric bursitis 4
• The crossed SLR test (pain produced when raising the unaffected leg) is more specific (88%) for disc herniation and would not be positive in isolated hip pathology 2, 5

Common Pitfalls in SLR Test Interpretation

• There is wide variation in clinical practice regarding the angle at which the SLR test is considered positive (range 10-90 degrees) 3
• The SLR test should be used in conjunction with other clinical findings and imaging when making treatment decisions 1
• A persistent positive SLR test after lumbar disc surgery correlates with poorer outcomes, indicating its specificity for nerve root issues rather than hip problems 6
• The slump test (a seated variant of SLR) shows substantial agreement with the SLR test (kappa = 0.69), further supporting that both tests assess neural tissue mechanosensitivity rather than hip joint pathology 7

Clinical Approach to Differentiating Sources of Pain

• When hip pain is suspected, specific tests like the FADIR test should be performed rather than relying on the SLR test 4
• Diagnostic imaging should include AP pelvis and lateral femoral head-neck radiographs to assist in diagnosing hip conditions 4
• MRI/MRA or CT scan is recommended where three-dimensional morphological assessment of the hip is indicated 4
• For patients with both hip and back symptoms, diagnostic injections can help determine the primary pain generator 4