title: The snapping medial antebrachial cutaneous nerve.
abstract: Snapping elbow is a well-known condition where elbow flexion and extension elicits a painful, popping sensation. The most frequent etiology is anterior dislocation of the ulnar nerve over the medial epicondyle. Four patients (3 females and 1 male) presented with complaints of a popping sensation in the elbow, pain over the medial aspect of the forearm, and ulnar neuritis. All patients underwent preoperative dynamic ultrasound and surgical exploration of the medial elbow. Intraoperatively, snapping of the MABC over the medial epicondyle was discovered in all four patients. In three patients, there was abnormal displacement of the medial triceps and ulnar nerve: in two of these, both structures dislocated over the medial epicondyle and in one patient both structures subluxated. In each case, the MABC was decompressed (n = 1) and transposed (n = 3), and in three cases, the medial triceps and ulnar nerve were addressed as well. Symptomatic improvement was achieved in all cases. Retrospective review of the ultrasound revealed the snapping MABC, though it was less effective prospectively in the cases when snapping MABC was not suspected. In conclusion, snapping of the MABC broadens the spectrum of disorders that results in snapping elbow. To our knowledge, we are unaware of prior reports of this entity.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.|Division of Urology, Saint Elizabeth's Medical Center, Tufts University School of Medicine, Brighton, Massachusetts.|Department of Anatomical Sciences, St George's University, Grenada, West Indies.
authors.forename: Alper
authors.initials: A
authors.lastname: Cesmebasi
authors.affiliation: Department of Orthopedics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Shawn W
authors.initials: SW
authors.lastname: O'driscoll
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota.|Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota.
authors.forename: Jay
authors.initials: J
authors.lastname: Smith
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota.
authors.forename: John A
authors.initials: JA
authors.lastname: Skinner
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.|Department of Orthopedics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Spinner
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000294:innervation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods; D014459:Ulnar Nerve / Q000000981:diagnostic imaging / Q000293:injuries*; D014463:Ultrasonography; D055815:Young Adult; D000092464:Elbow Injuries
keywords: median antebrachial cutaneous nerve; snapping elbow; ulnar neuritis;  medial epicondyle