Ultrasound-Guided Treatment of Peripheral Entrapment Mononeuropathies.

High-resolution neuromuscular ultrasound (US) is a valuable tool for the localization, diagnosis, and provision of conservative treatment to peripheral entrapment mononeuropathies. US-guided interventions require careful coordination of transducer and needle movement along with a detailed understanding of sonoanatomy. Preprocedural planning and positioning are instrumental in performing these interventions and should not be overlooked. Minimally invasive procedures, such as corticosteroid injections, aspiration of ganglia, orthobiologics, and hydrodissection, are useful options for the nonsurgical treatment of mononeuropathies refractory to conservative care. US is effective in determining atypical anatomy such as a bifid median nerve for improved accuracy and safety during injections, and precision based techniques such as hydrodissection may aid in physically separating the nerve from scar tissue and adhesions. The most well researched US guided treatment of entrapment neuropathy is carpal tunnel syndrome which demonstrates promising results from platelet-rich plasma, prolotherapy, hydrodissection, and percutaneous needle release. However, there is significant heterogeneity in procedure technique, injectate composition, injectate volume, and periprocedural conservative care that limits interpretation of the results and warrants continued head-to-head comparisons for research. This review highlights procedural details and outcomes for US-guided interventions of the most well-studied peripheral entrapment neuropathies. Despite many promising findings for these techniques, long-term outcomes and severe nerve compression may still benefit most from surgical decompression.