{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T11:07:32Z","timestamp":1779361652813,"version":"3.51.4"},"reference-count":30,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"20","license":[{"start":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T00:00:00Z","timestamp":1779062400000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Neurosurg Case Lessons"],"published-print":{"date-parts":[[2026,5,18]]},"abstract":"\n BACKGROUND<\/jats:title>\n Although the ulnar nerve typically follows a consistent course at the elbow, running within the condylar groove between the olecranon and the medial epicondyle, variations have been reported. The authors present the case of an anomalous ulnar nerve during cubital tunnel decompression surgery, where the nerve was found to be on an anterior course outside the ulnar groove medial to the epicondyle, entrapped by the fascia of the pronator mass.<\/jats:p>\n <\/jats:sec>\n \n OBSERVATIONS<\/jats:title>\n A 74-year-old male presented with advanced ulnar neuropathy resulting in progressive weakness and claw hand deformity of the left hand. Intraoperatively, the ulnar nerve was not found within the condylar groove between the olecranon and medial epicondyle, but was instead located medially to the epicondyle on top of the pronator retinaculum in a \u201ctransposed\u201d position. After release, the ulnar nerve remained stable, or without subluxation into the ulnar groove on flexion and extension of the elbow. To the authors\u2019 knowledge, only similar case reports of a stable, anteriorly positioned ulnar nerve have been cited in the literature.<\/jats:p>\n <\/jats:sec>\n \n LESSONS<\/jats:title>\n When the ulnar nerve deviates from its expected position in the condylar groove, surgeons must be prepared to extend the surgical incision as needed and consider preoperative imaging to delineate aberrant nerve trajectories.<\/jats:p>\n \n https:\/\/thejns.org\/doi\/10.3171\/CASE25788<\/jats:ext-link>\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3171\/case25788","type":"journal-article","created":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T12:55:47Z","timestamp":1779108947000},"source":"Crossref","is-referenced-by-count":0,"title":["Surgical implications of an anteriorly positioned ulnar nerve of unknown etiology at the elbow: illustrative case"],"prefix":"10.3171","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-5429-0300","authenticated-orcid":true,"given":"Emily M.","family":"Bandy","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, University of Illinois College of Medicine at Peoria"},{"name":"Department of Neurosurgery, Illinois Neurological Institute, OSF Saint Francis Medical Center, Peoria"},{"name":"School of Molecular and Cellular Biology\u2013Neuroscience, University of Illinois Urbana-Champaign, Urbana, Illinois"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2762-6460","authenticated-orcid":true,"given":"Jacques","family":"Lara-Reyna","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Illinois College of Medicine at Peoria"},{"name":"Department of Neurosurgery, Illinois Neurological Institute, OSF Saint Francis Medical Center, Peoria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dzung H.","family":"Dinh","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Illinois College of Medicine at Peoria"},{"name":"Department of Neurosurgery, Illinois Neurological Institute, OSF Saint Francis Medical Center, Peoria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1754","reference":[{"key":"bib1","article-title":"Cubital tunnel syndrome","unstructured":"Cubital tunnel syndrome. OHSU. Accessed September 29, 2025. https:\/\/www.ohsu.edu\/brain-institute\/cubital-tunnel-syndrome"},{"issue":"3","key":"bib2","series-title":"Hand Clin","first-page":"283","article-title":"Ulnar nerve anatomy","volume":"23","author":"Polatsch","year":"2007","unstructured":"Polatsch DBMelone CPJrBeldner SIncorvaia A.Ulnar nerve anatomy. Hand Clin. 2007;23(3):283-289. doi:10.1016\/j.hcl.2007.05.001"},{"issue":"11","key":"bib3","series-title":"Cochrane Database Syst Rev","first-page":"CD006839","article-title":"Treatment for ulnar neuropathy at the elbow","volume":"11","author":"Caliandro","year":"2016","unstructured":"Caliandro PLa Torre GPadua RGiannini FPadua L.Treatment for ulnar neuropathy at the elbow. Cochrane Database Syst Rev. 2016;11(11):CD006839. doi:10.1002\/14651858.CD006839.pub4"},{"issue":"10","key":"bib4","series-title":"Mol Neurobiol","first-page":"4232","article-title":"Collateral sprouting of peripheral sensory neurons exhibits a unique transcriptomic profile","volume":"57","author":"Lemaitre","year":"2020","unstructured":"Lemaitre DHurtado MLDe Gregorio CCollateral sprouting of peripheral sensory neurons exhibits a unique transcriptomic profile. Mol Neurobiol. 2020;57(10):4232-4249. doi:10.1007\/s12035-020-01986-3"},{"issue":"1","key":"bib5","series-title":"ISRN Neurol","first-page":"491892","article-title":"Diagnostic value of ultrasonography and magnetic resonance imaging in ulnar neuropathy at the elbow","volume":"2012","author":"Ayromlou","year":"2012","unstructured":"Ayromlou HTarzamni MKDaghighi MHDiagnostic value of ultrasonography and magnetic resonance imaging in ulnar neuropathy at the elbow. 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Surg Radiol Anat. 2016;38(10):1183-1189. doi:10.1007\/s00276-016-1695-9"},{"issue":"5","key":"bib8","series-title":"J Hand Surg Am","first-page":"984","article-title":"Anteriorly positioned ulnar nerve at the elbow: a rare anatomical event: case report","volume":"40","author":"Satteson","year":"2015","unstructured":"Satteson ESLi Z.Anteriorly positioned ulnar nerve at the elbow: a rare anatomical event: case report. J Hand Surg Am. 2015;40(5):984-986. doi:10.1016\/j.jhsa.2015.02.006"},{"issue":"6","key":"bib9","series-title":"Surgeon","first-page":"e402","article-title":"The prevalence of anconeus epitrochlearis muscle and Osborne\u2019s ligament in cubital tunnel syndrome patients and healthy individuals: an anatomical study with meta-analysis","volume":"19","author":"Suwannakhan","year":"2021","unstructured":"Suwannakhan AChaiyamoon AYammine KThe prevalence of anconeus epitrochlearis muscle and Osborne\u2019s ligament in cubital tunnel syndrome patients and healthy individuals: an anatomical study with meta-analysis. 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