Seated Straight Leg Raise Test; Sensitivity & Specificity in Patients with Disc Herniation at Lumbosacral Interface Using MRI as A Gold Standard

Abstract

Background: Lumbar disc herniation (LDH) at the L5-S1 level is a prevalent condition, often leading to lower back pain and sciatica. Diagnosing this condition accurately is crucial for effective treatment. The Straight Leg Raise (SLR) test, particularly in its seated variation, has been a subject of interest in clinical diagnostics due to its non-invasive nature and ease of administration. Objective: The study aimed to assess the diagnostic efficacy of the seated SLR test in identifying lumbar disc herniation at the L5-S1 level, comparing its results with Magnetic Resonance Imaging (MRI) findings. Methods: Conducted over one year, this validation study involved 117 patients at two hospitals in Bahawalpur. The age range of participants was 20 to 50 years, with an even distribution across three age groups. Both male and female patients experiencing low back pain radiating beyond the knee were included. The seated SLR test was administered in a standard manner, and pain was assessed using the Visual Analogue Scale (VAS). MRI was used as the gold standard for diagnosis. The study calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and test accuracy using a 2 x 2 contingency table. Results: The mean age of participants was 39.67±9.47 years. Gender distribution showed a female predominance with 68 females (58.2%) and 49 males (41.8%). Pain assessment revealed unilateral pain in most cases. The seated SLR test's sensitivity was found to be 48.8%, and specificity was 68.6%. The test’s accuracy stood at 51.2%, with a PPV of 78.2% and an NPV of 27.4%. Conclusion: The seated SLR test demonstrates moderate effectiveness in diagnosing lumbar disc herniation at the L5-S1 level. While it is more effective in confirming the diagnosis, its ability to exclude the condition is limited. This suggests the need for supplementary diagnostic methods in conjunction with the seated SLR test for a comprehensive evaluation.