Ultrasound-guided carpal tunnel injections

Abstract

Carpal tunnel syndrome (CTS) is one of the most common entrapment neuropathies, which represents a socio-economic issue due to lower work productivity, disability, and prolonged rehabilitation. Ultrasound (US) represents the imaging modality of choice in CTS imaging as several morphological parameters can be used in CTS diagnosis and follow-up. In recent years, the US-guided injection therapy for CTS has become an established treatment option for mild to moderate CTS, thus a narrative review paper on this topic is needed. The authors of this review paper performed a literature search that yielded several differences in US-guided carpal tunnel injection and summarized the differences in steps for further guidance: patient preparation, injection approach, needle positioning, injected medications, and injectate volume. Three approaches to carpal tunnel injections have been described in the literature namely ulnar, radial and longitudinal approaches. All three can be implemented with single- or multi- deposit and different injection volumes. Medications used for injections are corticosteroids, local anesthetics, dextrose, saline, platelet-rich plasma, and progesterone. No consensus has yet been reached concerning the best protocol to be used, however, the ulnar approach with single-deposit should be considered as the first choice, while D5W should be a first-line medication option injected in larger volumes. Furthermore, terminology differences between published papers make unification problematic, thus the presented steps of US-guided carpal tunnel injections might serve as guidance in further studies.