Abstract
Objective The objective of this study was to provide anatomical data on modified contralateral
C7 (cC7) nerve root transfers by dissecting and measuring the separable lengths of
the C7 root, trunk, and divisions.
Materials and Methods Fifteen adult cervicothoracic specimens were dissected and measured using Vernier
calipers after exposing the brachial plexus. Measurements included the length of the
C7 from the root to the trunk, the lengths of the C7 root–trunk–anterior division
(and posterior division). The epineuria at the C7 root–division–cord junctions were
opened until the internal nerve bundles fused together and could not be separated
by microdissection. The lengths of the C7 root–trunk–anterior (and posterior) division
were measured again after microdissection. The lengths of cC7 nerve of 20 patients
with bracial plexus avulsion were measured using the former technique.
Results The length of the C7 root–trunk was 45.87 SD 10.43 mm. Before separation, the lengths
of the C7 root–trunk–anterior division and the root–trunk–posterior division were
61.14 SD 13.44 and 54.63 SD 11.35 mm, respectively; after separation, the lengths
were 74.67 SD 12.86 and 68.73 SD 11.86 mm, respectively. The prolonged lengths were
13.15 SD 4.26 and 14.21 SD 6.98 mm, respectively. The prolonged lengths were significantly
greater (p < 0.05). The prolonged length of C7 nerve clinically was anterior division, 15.30
SD 3.76 mm and posterior division, 11.10 SD 3.01 mm.
Conclusion The C7 division lengths can be prolonged by dissecting the epineuria at the division–cord
junction of the C7 nerve root.
Keywords
length of C7 - microdissection - contralateral C7 nerve transfer
