Footnotes

• Contributors SD: drafting, review of literature, image labeling, cadaveric dissection, performed blocks. XS-B: review of literature, cadaveric dissection, performed blocks. AN: review of literature, manuscript editing and final proof. DS: scan interpretation, manuscript review.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; internally peer reviewed.