Chap, xxiv.] THE SPINE. 505 



the lower cervical region and the long processes of the 

 dorsal tract of the column are those that usually suffer. 

 The lumbar spines are less frequently broken, being 

 comparatively small and well protected by the great 

 muscles of the back. 



The transverse processes and laminae can scarcely 

 be fractured alone. 



In several instances of fracture-dislocation and of 

 fracture alone the spine has been trephined, or rather 

 portions of the laminae and spinous processes have been 

 resected. At the present time the operation is con- 

 sidered by most surgeons to be quite unjustifiable. It 

 involves a very deep wound, and an extensive dis- 

 turbance of the muscles and fasciae of the back. It 

 opens up the spinal canal, and affords an oppor- 

 tunity for blood or pus to enter it. In many cases 

 the rigidity of the injured spine depends upon the 

 locking of the posterior processes, and in this operation 

 the resection of some parts of those processes would 

 destroy the very desirable fixation of the column. In 

 the majority of instances the cord is crushed by the 

 projection backwards into the canal of the vertebra 

 immediately below the seat of the displacement, a 

 displacement that could not be remedied by any such 

 operation as the present. It is absurd, from an 

 anatomical point of view, to deduce any arguments in 

 favour of trephining the spine from the success of 

 the operation of the same name as applied to the 

 skull. Except in name the two procedures have little 

 in common. 



The spinal cord is in the adult about eighteen 

 inches in length, and extends from the lower margin 

 of the foramen magnum to the lower edge of the body 

 of the first lumbar vertebra. In some cases it ends at 

 the second lumbar, and in other instances at the last 

 dorsal vertebra. It is to be noted also that in flexion 

 of the spine the cord is a Httle raised. In the earlier 



