Subluxation of the ulnar nerve in the elbow region--ultrasonographic evaluation.

Chronic ulnar nerve subluxation out of its sulcus in the elbow region may be a rare reason for undefined chronic disorders in the medial elbow aspect. We present two cases, a 38-year-old male patient complaining of a recurrent painful disorder including paresthesia of the 4th and 5th fingers and a 12-year-old boy presenting with a palpable band in the medial elbow region without pain. Ultrasonography was performed using a high frequency linear probe in the longitudinal and horizontal planes including dynamic examination. In both patients, the ulnar nerve was completely identified, both in the transverse and longitudinal planes. The sonomorphology and echogeneity of the nerve were the same as in the contralateral limb. Ulnar nerve subluxation was diagnosed in elbow joint flexion, in both cases. It is possible through dynamic ultrasonographic examination to diagnose and document ulnar nerve subluxation for further (surgical) treatment.