Applied anatomy of the lateral side of the thoracolumbar spine

Objective:To provide anatomical basis for anterior approach of thoracolumbar interbody fusion assisted by thoracoscope.Methods:22 adult human cadaveric specimens(44 sides) were observed to record the course,distribution and relations of vessels and nerves on the lateral side of thoracolumbar spine.Results:On the lateral side of the thoracolumbar spine,there was a safe region without any important vessels and nerves,which were constituted by segmental vessels,sympathetic trunk,greater splanchnic nerve or lumbar plexus.Intervertebral space located in this safe region.At T10/11 and T11/12 intervertebral spaces,the area of safe region between the two sides showed significant difference(P0.05).On the left side,the area of each safe region was about 17.54 mm×17.53 mm and 20.50 mm×14.56 mm;on the right side,about 17.54mm×27.85mm and 20.50 mm ×21.47 mm respectively.However,at T12/L1,L1/2 and L2/3 intervertebral spaces,there was no significant difference of the area between two sides(P0.05).The areas of safe region at the same side increased gradually downward,which were 24.56 mm×19.95 mm,27.37 mm×25.31 mm,and 28.28 mm×27.51 mm respectively.Conclusions:On the lateral side of the thoracolumbar spine,intervertebral space locates in the safe region without any important vessels and nerves.During anterior approach for thoracolumbar interbody fusion assisted by thoracoscope,the safe region could supply a sufficient operating space.Intervertebral disc could be considered as an anatomical landmark to help to reduce the incidence of operative complications,such as injuries of vessel and nerve.