Diagnostic performance of the nerve root sedimentation sign in lumbar spinal stenosis: a systematic review and meta-analysis.

PURPOSE: This meta-analysis intends to use all available evidence to clarify the diagnostic performance of the nerve root sedimentation sign (NRSS). METHODS: The PubMed, EMBASE, the Cochrane Library database, China knowledge Infrastructure Project (CNKI), and Wanfang Database were searched up to January 2019 for relevant original studies. Data were extracted to calculate the pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive and negative likelihood ratios (PLR and NLR), and areas under summary receiver operating characteristic curve (SROC) for analysis. The clinical applicability was evaluated with a Fagan's plot and likelihood ratio dot diagram. Deek's funnel plot was used to assess publication bias. RESULTS: A total of 14 studies including 1333 positive cases and 2658 negative controls were available for the meta-analysis. The pooled sensitivity and specificity of the NRSS for the diagnosis of LSS was 0.84 (95% CI 0.75, 0.91) and 0.95 (95% CI 0.81, 0.99), respectively. The PLR was 18.6 (95% CI 4.0, 86.8), the NLR was 0.17 (95% CI 0.10, 0.28), and the DOR was 112 (95% CI 17,741). The SROC value was 0.93 (95% CI 0.91, 0.95). The Fagan's plot showed that the pre-test probability was 50% and the post-test probability was 95%. The likelihood ratio dot graph showed that the combined effect of the diagnosis fell on the right upper quadrant. Deek's funnel found no publication bias. CONCLUSION: NRSS has high diagnostic sensitivity, specificity, and efficacy, and good clinical application value for the diagnosis of LSS. It can be recommended as an auxiliary tool for diagnosis and screening in clinical practice.