High-Resolution Ultrasound in the Diagnosis and Surgical Management of Ulnar Neuropathy at the Elbow.

High-resolution ultrasound (HRU) has recently demonstrated the potential to facilitate diagnosis and treatment of upper extremity compression neuropathy. The authors hypothesized that HRU can improve preoperative evaluation of ulnar neuropathy at the elbow (UNE) and that changes in ulnar nerve cross-sectional area (CSA) after cubital tunnel release may correlate with outcomes. Nineteen adult patients diagnosed with UNE who were scheduled for surgical decompression by a single hand surgeon were enrolled. Electrodiagnostic (EDX) testing, HRU of the ulnar nerve, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, and McGowan grade were obtained pre- and postoperatively. Fourteen patients completed the study. Statistically significant improvements were found in CSA measurements and QuickDASH scores. High-resolution ultra-sound was found to confirm UNE in all 7 patients with positive results on EDX, and additionally detected UNE in 3 of 6 patients with negative results on EDX and in 1 patient with equivocal (nonlocalized) EDX testing. All 4 of these additional HRU-detected cases improved clinically and by CSA measurements after surgery. In this series, HRU was superior to EDX testing in the diagnosis of UNE and demonstrated objective improvement in ulnar nerve CSA after successful cubital tunnel release. This modality, which is better tolerated, less costly, and less time-consuming than EDX testing or magnetic resonance imaging, should therefore be considered in the diagnosis and surgical management of UNE, particularly in cases with negative or equivocal results on EDX testing, or when outcomes are suboptimal. [Orthopedics. 2021;44(5):285-288.].