Differentiating Hip and Lumbar Pathology using the Straight Leg Raise Test

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

Hip-related pain requires a comprehensive clinical examination that includes screening for other conditions that might present with similar symptoms (e.g., spine pathology), as recommended by the British Journal of Sports Medicine 3, 4
The FADIR test (flexion, adduction, internal rotation) is the recommended clinical test for screening hip-related pain, not the SLR test, according to the British Journal of Sports Medicine 5
Diagnostic imaging demonstrates only small to moderate shifts in post-test probability for hip pathology and should never be used in isolation, as stated by the British Journal of Sports Medicine 3
Hip conditions may cause pain that mimics radicular symptoms, but would not create a true positive SLR test, as noted by the Journal of the American College of Radiology 6

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, as recommended by the Journal of the American College of Radiology 7
Image-guided anesthetic injections can be used diagnostically to determine if pain is related to the hip joint rather than lumbar pathology, according to the Journal of the American College of Radiology 7
Ultrasound is useful for examining soft tissue structures around the hip for specific diagnoses such as trochanteric bursitis, as noted by the Journal of the American College of Radiology 7
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, as stated by the American College of Radiology 2

When hip pain is suspected, specific tests like the FADIR test should be performed rather than relying on the SLR test, as recommended by the British Journal of Sports Medicine 5
Diagnostic imaging should include AP pelvis and lateral femoral head-neck radiographs to assist in diagnosing hip conditions, according to the British Journal of Sports Medicine 4
MRI/MRA or CT scan is recommended where three-dimensional morphological assessment of the hip is indicated, as stated by the British Journal of Sports Medicine 4
For patients with both hip and back symptoms, diagnostic injections can help determine the primary pain generator, as noted by the Journal of the American College of Radiology 7