title: High-resolution ultrasound visualization of the recurrent motor branch of the median nerve: normal and first pathological findings.
abstract: OBJECTIVE
  To evaluate in a prospective study the possibility of visualization and diagnostic assessment of the recurrent motor branch (RMB) of the median nerve with high-resolution ultrasound (HRUS).
  
  
  METHODS
  HRUS with high-frequency probes (18-22 MhZ) was used to locate the RMB in eight fresh cadaveric hands. To verify correct identification, ink-marking and consecutive dissection were performed. Measurement of the RMB maximum transverse-diameter, an evaluation of the origin from the median nerve and its course in relation to the transverse carpal ligament, was performed in both hands of ten healthy volunteers (n = 20). Cases referred for HRUS examinations for suspected RMB lesions were also assessed.
  
  
  RESULTS
  The RMB was clearly visible in all anatomical specimens and all volunteers. Dissection confirmed HRUS findings in all anatomical specimens. Mean RMB diameter in volunteers was 0.7 mm ± 0.1 (range, 0.6-1). The RMB originated from the radial aspect in 11 (55%), central aspect in eight (40%) and ulnar aspect in one (5%) hand. Nineteen (95%) extraligamentous courses and one (5%) subligamentous course were detected. Three patients with visible RMB abnormalities on HRUS were identified.
  
  
  CONCLUSIONS
  HRUS is able to reliably visualize the RMB, its variations and pathologies.
  
  
  CONCLUSIONS
  • Ultrasound allows visualization of the recurrent motor branch of the median nerve. • Ultrasound may help clinicians to assess patients with recurrent motor branch pathologies. • Patient management may become more appropriate and targeted therapy could be improved.
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria. georg.riegler@meduniwien.ac.at.
authors.forename: Georg
authors.identifier: http://orcid.org/0000-0001-5161-0456
authors.initials: G
authors.lastname: Riegler
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria.
authors.forename: Christopher
authors.initials: C
authors.lastname: Pivec
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria.
authors.forename: Hannes
authors.initials: H
authors.lastname: Platzgummer
authors.affiliation: Department of Neurology, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria.
authors.forename: Doris
authors.initials: D
authors.lastname: Lieba-Samal
authors.affiliation: Department of Anatomy, Center for Anatomy and Cell Biology, Medical University of Vienna, Währingerstrasse 13, 1090, Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Brugger
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria.
authors.forename: Suren
authors.initials: S
authors.lastname: Jengojan
authors.affiliation: Department of Surgery, Division of Plastic and Reconstructive Surgery, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Vierhapper
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090, Vienna, Austria.
authors.forename: Gerd
authors.initials: G
authors.lastname: Bodner
mesh_terms: D000328:Adult; D002102:Cadaver; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis*; D005260:Female; D006225:Hand / Q000294:innervation*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D014463:Ultrasonography / Q000379:methods*
keywords: Anatomical variation; Carpal tunnel syndrome; Iatrogenic disease; Median nerve; Ultrasound