Ultrasound-guided carpal tunnel injections

Abstract

Background: Carpal tunnel syndrome (CTS), one of the most common entrapment neuropathies, can, in fact, be considered as a socio-economic issue that reduces work productivity, increases disability, and requires prolonged rehabilitation. The imaging modality of choice in CTS imaging is the ultrasound (US), as several morphological parameters can be used in CTS diagnosis and follow-up. In recent years, US-guided CTS injection therapy has become an established treatment option for mild to moderate CTS. The authors of this review performed a literature search that revealed several differences in US-guided carpal tunnel injection in an attempt to unify individual stages of CTS injections protocol for future guidance: patient preparation, injection approach, needle positioning, injected medications, and injectate volume. The three approaches to carpal tunnel injections described in the literature, that is, the ulnar, radial, and longitudinal, can be implemented with single or multiple deposits and different injection volumes. Medications used for injections are corticosteroids, local anaesthetics, dextrose, saline, platelet-rich plasma, and progesterone.

Conclusions: Although no consensus has yet been reached as to which protocol should be used, the ulnar approach with a single deposit injected in large volumes should be considered as the first choice, while dextrose should be the first-line medication option. Furthermore, as terminological differences make it difficult to draw a uniform comparison the presented steps for US-guided carpal tunnel injection might serve as a guideline for future studies.

Keywords: carpal tunnel syndrome; corticosteroid; injection approach; local anaesthetics; needle positioning; ultrasound-guided injections.