Last modified: 2012-02-18
Abstract
Purpose: The purpose of this study was to determine the accuracy of the straight leg raise (SLR) and slump tests in detecting lumbar disc Herniation (LDH), and to compare the agreement of either test with the result of magnetic resonance imaging (MRI), Relevance: Low back pain (LBP) is the most prevalent musculoskeletal disorder, and one of its most common causes is LDH which often compresses the nerve root resulting in pain that radiates down into the legs. MRI is the gold standard diagnostic procedure for LDH. However, MRI is not widely available in Rwanda and many developing countries, and where it is, the costs are highly prohibitive. The SLR and slump tests are clinical diagnostic procedures used by physiotherapists to detect LDH, but the literature is inconclusive as to which one of the two tests is more accurate. Participants: All patients aged 18 to 70 years with pain in the low back, leg, or low back and leg, and an MRI investigation at King Faisal Hospital, Kigali (KFH, K) and Centre Hospitalier Universitaire de Kigali (CHUK) were studied. Methods: A cross-sectional diagnostic accuracy design was used to conduct this pilot study. A checklist adopted from Standards for Reporting of Studies of Diagnostic Accuracy (STARD) was used to collect data. Analysis: Data were analyzed using SPSS 14.0. Sample characteristics were analyzed descriptively. Sensitivity and specificity were computed respectively at a 95% CI. Kappa (K) coefficient was computed for the agreement for each test with the MRI at the 95% CI. Results: A final sample of 33 patients, mean age 41.58 ± 10 years was analyzed. Most patients (n = 20) had LDH below lumbar level 3. The sensitivity of the SLR was greater (0.875; CI: 0.690-0.957) than that of the slump test (0.800; CI: 0.6087-0.911). The specificity for the SLR was 0.429 (CI: 0.158 -0.750) and for the slump test was 0.714 (CI: 0.359-0.918). A moderate agreement (K = 0.446) was obtained between the slump test and MRI, whereas, substantial agreement (K= 0.774) was obtained between the SLR and MRI. Conclusion: The SLR was more accurate in detecting LDH in patients with LDH at the lower levels of the lumbar spine. Further validation of this pilot finding is required by studying a larger sample with representation of LDH at all levels of the lumbar spine, and randomizing recruitment and selection of patients for study. Implications: The SLR may offer an alternative and time and cost-effective procedure to detect LDH. Substantial savings on the cost of MRI investigations and the possibility of accurate diagnosis of LDH in the absence of MRI enhances the overall quality of care of these patients.
Keywords: accuracy, SLR test, Slump test, LDH