Ultrasonographic measurement of humeral torsion.

This article presents a new method for the measurement of humeral torsion with the use of ultrasonography and discusses clinical applications of the method such as the evaluation of cubitus varus deformity after a supracondylar elbow fracture. Torsion angle increased 14 degrees from the time the patients were newborns to when they were adults. No significant difference was found between the right and left sides in healthy subjects. When humeral shaft or supracondylar fractures are treated, or when rotational deformities of the humerus are corrected, this method of measurement is very practical, because the humeral torsion of the unaffected side provides a standard for the individual. With this method of measuring humeral torsion, we also found that cubitus varus deformity after supracondylar fracture in children is caused not only by an increase in varus angulation but also by internal rotation of the distal fragment.