The Sensitivity and Specificity of Ultrasound for the Diagnosis of Carpal Tunnel Syndrome: A Meta-analysis

Abstract

Background Carpal tunnel syndrome (CTS) is the most commonly diagnosed compression neuropathy of the upper extremity. Current AAOS recommendations are to obtain a confirmatory electrodiagnostic test in patients for whom surgery is being considered. Ultrasound has emerged as an alternative confirmatory test for CTS; however, its potential role is limited by lack of adequate data for sensitivity and specificity relative to electrodiagnostic testing. Questions/purposes In this meta-analysis we determined the sensitivity and specificity of ultrasound in the diagnosis of CTS. Methods A PubMed/MEDLINE search identified 323 articles for review. After applying exclusion criteria, 19 articles with a total sample size of 3131 wrists were included for meta-analysis. Three groups were created: a composite of all studies, studies using clinical diagnosis as the reference standard, and studies using electrodiagnostic testing as the reference standard. Results The composite sensitivity and specificity of ultrasound for the diagnosis of CTS, using all studies, were 77.6% (95% CI 71.6-83.6%) and 86.8% (95% CI 78.9-94.8%), respectively. Conclusions The wide variations of sensitivities and specificities reported in the literature have prevented meaningful analysis of ultrasound as either a screening or confirmatory tool in the diagnosis of CTS. The sensitivity and specificity of ultrasound in the diagnosis of CTS are 77.6% and 86.8%, respectively. Although ultrasound may not replace electrodiagnostic testing as the most sensitive and specific test for the diagnosis of CTS given the values reported in this meta-analysis, it may be a feasible alternative to electrodiagnostic testing as the first-line confirmatory test.

Quantitative magnetic resonance (MR) neurography for evaluation of peripheral nerves and plexus injuries

“…Numerous studies have demonstrated with proper results the utility of ultrasound (59) and conventional MRI studies to evaluate median nerve at flexor retinaculum (60). However, in some patients there is not apparent cause of median nerve compression despite the presence of clinical symptoms.…”

Ultrasound as a First-line Test in the Diagnosis of Carpal Tunnel Syndrome: A Cost-effectiveness Analysis

“…The AAOS, however, does not specify which test should be used [17]. A recent meta-analysis [9] showed comparable sensitivity and specificity of ultrasound and electrodiagnostic testing (EDX) in the diagnosis of carpal tunnel syndrome (CTS). Despite this evidence, there is an anecdotal bias toward the preferential use of EDX over ultrasound to confirm clinical findings in the diagnosis of CTS.…”

“…EDX, defined as a combination of nerve conduction studies and electromyography, has been used as the gold standard for the diagnosis of CTS [2,7,9,15,24,28,[32][33][34]. The American Association of Electrodiagnostic Medicine (AAEM) has defined a standard protocol for EDX to detect focal nerve conduction slowing and changes in muscle innervation in patients suspected of having CTS [15].…”

“…The American Association of Electrodiagnostic Medicine (AAEM) has defined a standard protocol for EDX to detect focal nerve conduction slowing and changes in muscle innervation in patients suspected of having CTS [15]. EDX has a high specificity [9,25], but also a falsenegative rate of 10% to 20% [14,16,19,25].…”

“…The reported sensitivity and specificity of ultrasound varies from 57% to 98% and 51% to 100%, respectively with a false negative rate of approximately 20% [9]. Ultrasound is operator-dependent and unable to differentiate distal from proximal compression [9,24].…”