Entrapment neuropathy of the ulnar nerve by a constriction band: the role of MRI.

The diagnosis of ulnar nerve entrapment at the elbow has relied primarily on clinical and electrodiagnostic findings. Magnetic resonance imaging (MRI) has been used in the evaluation of peripheral nerve entrapment disorders to document signal and configurational changes in nerves. In this case report we review the MRI and operative findings of a rare constriction band causing ulnar nerve compression at the elbow. We review the sensitivity and specificity in diagnosing ulnar nerve entrapment at the elbow as defined by MRI findings.