A case of ulnar nerve section at the elbow alleviated by Martin-Gruber communicating branch. Diagnostic characterization.

Martin-Gruber communicating branch may be a confounding factor in the diagnosis of ulnar neuropathy at the elbow. It may also lead to a surprising level of motor function conservation despite evident neuropathy. We present a patient with ulnar nerve section at the elbow who underwent early treatment by nerve suture. At 7 months, function was good, despite sonographic findings of neurotmesis at the elbow. Electroneurography revealed Martin-Gruber communicating branch. This type of communicating branch can be associated with functional conservation despite ulnar nerve section. Electrophysiological and ultrasound findings can be highly contributive in defining these conditions.