Morphological-biomechanical dual-cornerstone framework: quantitative ultrasound for electrodiagnostically negative carpal tunnel syndrome.

BACKGROUND

The diagnosis of carpal tunnel syndrome (CTS) is frequently challenging when typical clinical presentations conflict with negative electrodiagnostic (EDX) findings. Quantitative ultrasound (QUS) can detect early neuropathophysiological changes that precede electrophysiological abnormalities; however, its clinical application is limited by the lack of a systematic diagnostic framework.

OBJECTIVE

To construct and validate an integrative QUS diagnostic framework for patients with clinically suspected CTS but negative or inconclusive EDX results.

METHODS

We conducted a comprehensive literature search in PubMed and Embase (January 2015-March 2025) for studies reporting diagnostic performance metrics of QUS parameters in CTS. Based on critical evidence synthesis and clinical practice experience, we developed a systematic diagnostic framework integrating key QUS parameters into a clinical decision-making pathway.

RESULTS

A dual-cornerstone strategy integrating nerve morphology (CSA: AUC 0.75-0.95; sensitivity 75-92%; specificity 83-95%) and tissue biomechanics (SWE: AUC 0.76-0.97; sensitivity 70-95%; specificity 78-95%) provides superior diagnostic value compared with single parameters, with combined models achieving AUC >0.90. We present a practical clinical toolkit comprising diagnostic thresholds, a four-quadrant decision matrix, and a quantitative scoring system. Preliminary validation in 78 EDX-negative patients demonstrated that 92% (72/78) scoring ≥5 points achieved significant symptom improvement following standardized treatment.

CONCLUSIONS

Through its "morphology + biomechanics" dual-cornerstone strategy, QUS effectively identifies electrophysiologically occult CTS and serves as an indispensable complement to EDX in specific diagnostic scenarios.