title: Ulnar Nerve Entrapment by an Additional Slip of the Triceps Brachii.
abstract: Additional slips of the triceps brachii have been reported in cadaver studies. We report the case of a 48-year-old man with no history of trauma who presented with a tingling sensation and weakness in his right hand. Electromyography revealed ulnar neuropathy around the elbow, with decreased conduction proximal to the medial epicondyle. On ultrasonography and magnetic resonance imaging, the ulnar nerve was found to be mildly swollen and covered by an additional slip of the triceps brachii muscle above the retrocondylar area. Upon full elbow flexion, this anatomy produced dynamic compression of the vessels surrounding the nerve. Despite conservative treatments for over 2 months, the patient had minimal symptom improvement. Decompression and anterior transposition of the ulnar nerve were performed with favorable results. Additional slips of the triceps brachii muscle can compress neurovascular structures and cause ulnar neuropathy at the elbow. Ultrasonography is useful in the evaluation of such neurovascular compression.
authors.affiliation: From the Departments of Physical Medicine and Rehabilitation (KHK, BKP, DHK) and Orthopedic Surgery (JWP), Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ki Hoon
authors.initials: KH
authors.lastname: Kim
authors.forename: Jong Woong
authors.initials: JW
authors.lastname: Park
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Park
authors.forename: Dong Hwee
authors.initials: DH
authors.lastname: Kim
mesh_terms: D001917:Brachial Plexus / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D019299:Decompression, Surgical / Q000379:methods; D004550:Elbow / Q000473:pathology / Q000601:surgery; D004576:Electromyography; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014459:Ulnar Nerve / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D017769:Ulnar Nerve Compression Syndromes / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014463:Ultrasonography