title: Microanatomy of the brachial plexus roots and its clinical significance.
abstract: OBJECTIVE
  To provide the anatomical basis of brachial plexus roots for the diagnosis and treatment of brachial plexus root avulsion injury.
  
  
  METHODS
  The morphological features of brachial plexus roots were observed and measured on 15 cervicothoracic spine of adult cadavers. The relationship of brachial plexus nerve roots and the surrounding tissues also were observed, as well as the blood supply of anterior and posterior roots of the brachial plexus.
  
  
  RESULTS
  Origination of the nerve roots in the dorsal-ventral direction from the midline was fine-tuned at each level along the spinal cord. The minimum distance of the origin of the nerve root to midline was 2.2 mm at C5, while the maximum was 3.1 mm at T1. Inversely, the distance between the origin of the posterior root and the midline of the spinal cord gradually decreased, the maximum being 4.2 mm at C5and minimum 2.7 mm at T1. Meanwhile, there was complicated fibrous connection among posterior roots of the brachial plexus. The C5-6nerve roots interlaced with tendons of the scalenus anterior and scalenus medius and fused with the transverse-radicular ligaments in the intervertebral foramina. However, these ligaments were not seen in C7-8, and T1. The blood supply of the anterior and posterior roots of the brachial plexus was from the segmental branches of the vertebral artery, deep cervical artery and ascending cervical artery, with a mean outer diameter of 0.61 mm.
  
  
  CONCLUSIONS
  The systematic and comprehensive anatomic data of the brachial plexus roots provides the anatomical basis to diagnose and treat the brachial plexus root avulsion injury.
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China.
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Zhong
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China.
authors.forename: Ai-Ping
authors.initials: AP
authors.lastname: Wang
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China.
authors.forename: Li
authors.initials: L
authors.lastname: Hong
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China.
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Chen
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China.
authors.forename: Xian-Qin
authors.initials: XQ
authors.lastname: Wang
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China. anthony0723@163.com.
authors.forename: Yun-Cheng
authors.initials: YC
authors.lastname: Lv
authors.affiliation: Laboratory of Clinical Anatomy, University of South China, Hengyang, 421001, Hunan, China. thpeng67@163.com.
authors.forename: Tian-Hong
authors.initials: TH
authors.lastname: Peng
mesh_terms: D000328:Adult; D001917:Brachial Plexus / Q000033:anatomy & histology* / Q000098:blood supply; D020516:Brachial Plexus Neuropathies / Q000601:surgery; D002102:Cadaver; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000098:blood supply; D006801:Humans; D013126:Spinal Nerve Roots / Q000033:anatomy & histology* / Q000098:blood supply; D013904:Thoracic Vertebrae / Q000033:anatomy & histology / Q000098:blood supply
keywords: Avulsion of the brachial plexus; Blood supply of the brachial plexus; Microanatomy; Roots of the brachial plexus