Romanian Neurosurgery (Jun 2021)

C7 contribution to the ulnar nerve

  • Lívio Pereira de Macêdo,
  • Arlindo Ugulino Netto,
  • Kauê Franke,
  • Pierre Vansant Oliveira Eugenio,
  • Lucas Ribeiro de Moraes Freitas,
  • Fábio Antônio Serra de Lima Júnior,
  • João Vitor Romeiro de Paula,
  • Silvya Nery Bernardino,
  • Fernando Henrique Morais de Souza,
  • Nivaldo S. Almeida,
  • Hildo Rocha Cirne Azevedo-Filho

Journal volume & issue
Vol. 35, no. 2

Abstract

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Introduction. Classic anatomical literature frequently describes C7 contribution to ulnar nerve (UN) formation as a casual event. However, surgical practice and dissections frequently reveal a recurrent presence of a lateral cord component of the UN. This study aimed to seek through literature to establish the frequency and degree of this contribution. Methodology. We ran a literature review searching on Pubmed, MEDLINE, Embase and Web of Science databases for ulnar nerve anatomy and described discursively the results. Results and discussion. We found 9 articles that described quantitatively and qualitatively the contribution of C7 on the formation of the UN. The prevalence described ranged from 2 to 100%, depending on the methodology used and population characteristics. When present, studies described a contribution from 9,9% to 30,4%, sending even more fibres than T1 root on average. Conclusion. The C7 root can be considered a frequent and important component of the ulnar nerve, explaining UN territory repercussions on C7 radiculopathies. This knowledge is important on surgical approaches, maybe avoiding iatrogenic lesions and negative outcomes.

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