Spinal A bscesses 2 1 1 



to form a dorsal abscess. If it point forwards it may perchance open 

 into the oesophagus, trachea or bronchus, pleura or pericardium. Or 

 the pus may track forwards between the intercostal muscles, or between 

 the inner intercostal muscle and the pleura, to point at the side of the 

 sternum or of the rectus abdominis, or in some chosen part of the inter- 

 costal space. But more often it descends in the posterior mediastinum 

 till it reaches the diaphragm, which it traverses under the inner or 

 outer arcuate ligament : if under the former, to descend as a psoas 

 abscess ; if under the latter, to bulge as a lumbar abscess. When the 

 psoas abscess has passed beneath Poupart's ligament it usually bulges 

 on the outer side of the femoral vessels, and it not infrequently works 

 thence, inwards and backwards, following the internal circumflex, to 

 form a gluteal abscess. 



In lumbar caries the pus generally collects beneath the iliac fascia 

 to form an iliac or psoas abscess. In the former case the tumour 

 bulges in the iliac fossa, probably to point above Poupart's ligament ; 

 in the latter case it finds its way beneath the ligament, and points in 

 Scarpa's triangle. In these cases, by pressing with one hand in the 

 iliac fossa and the other in the triangle, one can get a ' see-saw ' with 

 the fluid under Poupart's ligament, especially when the thigh is slightly 

 flexed. 



But an iliac or a psoas abscess may push forwards and open into 

 the peritoneal cavity, the alimentary canal, or ureter, or may descend 

 into the bladder or ischio-rectal fossa, or, following the lumbo-sacral 

 cord and the great sciatic, through the great sacro-sciatic notch, to 

 form a gluteal abscess. 



It frequently happens that pus which has descended beneath the 

 outer arcuate ligament, or which, in lumbar caries, has been collecting 

 anterior to or in the substance of the quadratus lumborum, escapes 

 backwards in the gap between the twelfth rib and the iliac crest to 

 form a lumbar abscess. In this course it passes through that weak 

 part of the abdominal wall which is bounded in front by the posterior 

 border of the external oblique, behind by the latissimus dorsi, and 

 below by the iliac crest the triangle of Petit (p. 305). I have operated 

 for the cure of a reducible lumbar hernia in the case of a piece of bowel 

 escaping by the track of an old lumbar abscess. 



Fractures and dislocations are fairly common in the cervical 

 region, where the vertebras are small and the range of movement is free. 

 Unless the lesion be associated with displacement of a vertebra, it may 

 pass unrecognised ; the most serious condition is that in which displace- 

 ment causes pressure upon the cord. When the displacement is con- 

 siderable the cord is torn across, or firmly compressed, and the symptoms 

 are immediate. If the displacement be but slight, there maybe no symp- 

 toms at first, but, as the local disturbance of the cord is followed by inflam- 

 mation, its functions become impaired and the symptoms manifested. 

 Thus, the patient is paraplegic (TrapaTrXr/^, struck badly), that is to say, 



