THE INSTRUMENTS FOR EMBRYOTOMY 269 



The vertebral embryotome is employed to amputate the 

 neck, dorsal or lumbar region. According to Boer, it may also 

 be used to sever muscular tendinous tissue around the scapula, 

 coxo-femoral articulation. 



The first to introduce the saw into obstetrics was the 

 Hollandish veterinarian, J. H. Hinze, at Mijdrecht. It con- 

 sists of a rod 72 cm. long, with a sawing surface (14 cm.) on 

 one end (fig. 59). 



Fig. 59.— Saw with Handle. 



It is used to cut through the body of the inferior maxilla, 

 temporo-maxillary articulation, the ribs, the sacro-iliac articula- 

 tion and the ischio-pubic symphysis. 



The long sharp hook, the vertebral knife, and Hinze's saw 

 are only employed in subcutaneous embryotomy. They are 

 only of use when the skin has been previously separated to 

 quite some extent by the hand or spatula. The hand, which 

 always covers the instruments, lies underneath the skin. 



Fig. 60.— Chain Saw. 



Persson introduced the chain saw into obstetrical practice. 

 Sjostedt described it in 1875 in his "Handbok i Forlossings- 

 konsten." On each end is a ring to fasten a rope (fig. 60). 

 The chain saw is convenient to remove the head, to cut through 

 legs abnormally presented; for instance, a carpus wedged in the 

 vagina with the leg turned backward. The chain saw may also 

 be employed to cut contractions of the neck and the sacro-iliac 

 articulation in subcutaneous embryotomy. 



