2025 Workshop Handout Bundle-W81A Basic US of lower limb nerves

W81A Basic US of lower limb nerves - Strakowski

Pdf Summary

This document provides an overview of musculoskeletal ultrasound (MSK US) with a focus on lower limb nerves and tendon pathologies, authored by Dr. Jeffrey A. Strakowski and Dr. John Norbury. MSK US utilizes sound waves to detect pathologies in tendons, ligaments, joints, muscles, and nerves. It is distinct yet overlapping with neuromuscular ultrasound (NMUS), the former emphasizing orthopedic conditions and the latter peripheral nervous system disorders.<br /><br />Advantages of MSK US include superior spatial resolution, cost-effectiveness compared to MRI, safety without radiation exposure, real-time dynamic imaging, and point-of-care application. Limitations involve difficulty imaging internal joint structures obscured by bone (e.g., labral tears), reliance on operator skill, and inability to fully assess some deep pathologies.<br /><br />High-frequency linear transducers are preferred, employing movements like sliding, rocking (heel/toe), tilting, rotation, and compression to optimize imaging. Tissue sonography depends on recognizing characteristic patterns: tendons show hyperechoic fibrillar architecture prone to anisotropy (image artifacts from off-angle transducer placement), nerves exhibit fascicular patterns with relative hypoechogenicity, muscles have pennate or “starry night” appearances, ligaments appear striated between bones, and joints can provide landmarks via bony outlines and hyaline cartilage.<br /><br />A detailed checklist guides scanning of upper and lower limb structures, including hip tendons, nerves, knee ligaments, ankle tendons, and neural pathways, with recommended patient and limb positioning.<br /><br />Common tendon pathologies discussed include tendinosis—characterized by tendon enlargement, hypoechogenicity, loss of fibrillar pattern, and increased Doppler signal—and tendon tears, ranging from partial longitudinal to full thickness, seen as sharp borders and anechoic gaps on ultrasound. The term "tendinitis" is discouraged, as most are degenerative rather than inflammatory.<br /><br />Overall, MSK US is a valuable, cost-effective tool for evaluating soft tissue and nerve pathology of the lower limb, with effectiveness dependent on operator proficiency and adherence to imaging protocols. The document also references multiple guidelines and technical resources for further study.

Keywords

musculoskeletal ultrasound

lower limb nerves

tendon pathologies

orthopedic conditions

high-frequency linear transducers

tendinosis

tendon tears

anisotropy artifact

real-time dynamic imaging

operator skill