The Anatomical Study Of Contralateral C7 Transfer Through The Vertebral Body Route

Objective:Now never transposition is the major treatment technique for brachial plexus avulsion. More than ten procedures including never transfer of extra-plexus and intra-plexus has been used to repair the single injure never because the never fibers are shortage. Contralateral C7 nerve transfer for brachial plexus avulsion injuries is the most general procedure because C7 never root supplis plenty of never fibers. C7 never root is short, traditional methods need long bridge never to transplant. Recipient muscle form denervation muscle atrophy and fibration because of longer distance of never regeneration and operation cycle time. Procedure of contralateral C7 nerve transfer through prespinal route shorten the distance of never regeneration and reduce the quantity of stoma .Contralateral C7 never can inosculate with lower trunk directly. To reduce the tension at stoma, the nevers at recipient site need to solute in operation, shoulder joint need to be located in the position of endoduction and anteflexion after operation. Therefore, for shortening the distance between never and dismissing the tension of stoma, we have designed the spinal route for finding the optimal route of contralateral C7 nerve transfer for brachial plexus avulsion injuries through autopsy.Methods:The roots and trunks bilateral brachial plexus were exposed on 30 sides of 15 cadaveric specimens of adult through the general operative route of exploration of brachial plexus at supraclavicular. The C7 nerve root was sectioned at the junction site of trunk and division, and then dissected proximally to the foramina. The max length of anterior and posterior division of C7 was measured. The diameter of nerve root of C7, the height and transverse diameter of vertebral body of C7, the distance from the intervertebral foramen to anterior border of vertebral body of C7 were measured.The distance from the intervertebral foramen of C7 to the upper trunk and the lower trunk at the affected side through vertebral body route, prespinal route and a subcutaneous tunnel on the anterior surface of the neck was measured.Results:The length of C7 nerve root was (64.3±7.2)mm .The max length of anterior and posterior division of C7 was (76.7±10.6) mm and (77.9±13.6) mm respectively. The transverse and longitudinal diameter of the C7 nerve root was (5.4±0.5) mm and (5.1±0.5)mm at intervertebral foramen, was (5.3±0.6) mm and (5.0±0.4)mm at the junction site of trunk and division. The transverse diameter of vertebral body of C7 was (28.2±2.2) mm at superior part, (29.3±1.8) mm at middle part, (26.5±2.0) mm. The height of vertebral body was (12.5±1.2) mm at both sides, (14.3±1.5) mm at anterior border. The distance from the intervertebral foramen to anterior border of vertebral body of C7 was (8.5±0.8) mm. The hole that had been drilled at middle of the side of vertebral body was regard as the vertebral body route. The distance from the intervertebral foramen to the upper trunk at the affected side through vertebral body route, prespinal route and a subcutaneous tunnel on the anterior surface of the neck was (69.7±5.6) mm and (100.4±9.4) mm and (165.6±12.4) mm respectively, there were statistical significance among them (p<0.01). The distance from the intervertebral foramen to the lower trunk at the affected side through vertebral body route and prespinal route and a subcutaneous tunnel on the anterior surface of the neck was (68.2±9.2) mm, (99.1±8.3) mm and (176.4±9.7) mm, with a significant difference (p<0.01). The max length of anterior and posterior division of C7 was (76.7±10.6) mm and (77.9±13.6) mm exceed respectively the distance from the intervertebral foramen of C7 to the upper trunk and lower trunk at the affected side through spinal route (69.7±5.6) mm and (68.2±9.2) mm.Conclusions:Through 30 sides of 15 cadaveric specimens of adult, the hole that had been drilled at middle of the side of vertebral body was regard as the vertebral body route. The contralateral C7 nerve can inosculate with upper and lower trunk directly without tension through vertebral body route. The distances from the intervertebral foreman of C7 to the upper trunk at the affected side through vertebral body route, prespinal route and a subcutaneous tunnel on the anterior surface of the neck were statistical significance among them (p<0.01). The best ways of contralateral C7 nerve transfer for the treatment of brachial plexus injury was through vertebral body route from the point of anatomy. A new anatomic evidence of contralateral C7 nerve transfer for brachial plexus avulsion injuries is provided for clinic.