Musculoskeletal ultrasound for traumatic and torsional alterations.

The sonographic appearance of soft tissue can be altered by trauma and positional change with torsional stress. This creates challenges for ultrasonographic interpretation, because most descriptive literature and standard instructional references are displayed in anatomically neutral or other conventional positions. Knowledge of anatomic alteration and changes in sonographic appearance with torsional stress is essential for accurately assessing soft tissue abnormalities in conditions of spasticity, traumatic and post-surgical changes, and other conditions that distort musculoskeletal relationships. A systematic scanning approach to these alterations is needed for accurate diagnostic interpretation, optimizing electrode placement for electrodiagnostic techniques, effective needle placement for therapeutic ultrasound-guided procedures, and even planning for restorative surgery. This review describes expected positional changes of normal structures with torsional alteration, as well as sonographic recognition of scars, burns, hematomas, fat layer fracture, Morel-Lavallee lesions, abscesses, foreign bodies, myotendinous lesions, muscle injury and denervation, and traumatic peripheral nerve injury.