Ulnar Nerve and Cubital Tunnel Ultrasound in Ulnar Neuropathy at the Elbow

Abstract Yoon JS, Hong S-J, Kim B-J, Kim SJ, Kim JM, Walker FO, Cartwright MS. Ulnar nerve and cubital tunnel ultrasound in ulnar neuropathy at the elbow. Objective To determine the accuracy of the ultrasonographic measurement of ulnar nerve to cubital tunnel area for diagnosis of ulnar neuropathy at the elbow. Design Patients with confirmed ulnar neuropathy at the elbow and normative, healthy volunteers were evaluated with high-resolution ultrasound. The cross-sectional areas (CSAs) of the ulnar nerve and cubital tunnel were measured with the elbow extended and flexed, and results from the 2 groups were compared. Setting Electromyography laboratory and radiology department of a tertiary care center. Participants Twenty-seven patients with ulnar neuropathy at the elbow and 20 controls. Interventions Not applicable. Main Outcome Measure The ratio of ulnar nerve to cubital tunnel CSA with the elbow flexed. Results The ulnar nerve, with the elbow flexed, was larger in those with ulnar neuropathy at the elbow, and this group also had larger cubital tunnels than did controls. In those with ulnar neuropathy at the elbow, the ratio of the ulnar nerve to cubital tunnel was .31, and in the controls it was .32, which was not significantly different ( P =.89). Conclusions The ratio of ulnar nerve to cubital tunnel did not differentiate those with ulnar neuropathy at the elbow from controls.