200 



PELVIS. 



In these cases, according to Ramsbotham, 

 it is rare that the transverse diameter does not 

 exceed three inches. Less room is required 

 if the brim alone be distorted, according to the 

 same author. 



All pelves contracted in their diameters be- 

 low the measurements given in the last list 

 may undoubtedly be considered to require, for 

 the delivery of a foetus of viable or full-grown 

 size, the abdominal section. 



Dr. Robert Lee, however, advocates strong- 

 ly, and with great justice, the propriety of 

 inducing abortion in these deplorable cases, 

 as a means of saving the life of the mo- 

 ther. When the sacro-pubic diameter is 

 below li inch at the brim, this author 

 considers that abortion should be induced 

 before the fifth month. According to Ritgen, 

 labour should be induced in the twenfy- 

 ninth week, when the sacro-pubic diameter 

 is 2 inches 7 lines ; in the thirtieth week, 

 when it is 2 inches 8 lines; in the thirty- 

 first, when 2 inches 9 lines ; in the thirty- 

 fifth, when 2 inches 10 lines; in the thirty- 

 sixth, when 2 inches 11 lines; and in the 

 thirty-seventh, when exactly 3 inches. When 

 above 3 inches, the case should be left to na- 

 ture. Barlow thinks that premature labour 

 should be induced when this diameter is con- 

 tracted to 2i or 2f inches.* 



But in many cases, especially on the Con- 

 tinent, a much less degree of "contraction of 

 the conjugate diameter has been thought suf- 

 ficient to justify the Caesarian operation. In 

 a table given by Velpeanf, out of sixty-two 

 cases where narrowness of the conjugate 

 diameter was the reason adduced for adopt- 

 ing this operation, in one case it was 1 inch 

 only; in eight cases, Ji inch; in twenty- 

 three cases, Ji to 2 inches; in twenty-five 

 cases, 2 to 2i inches; and in five cases, 

 2i to 2f inches. These, without doubt, in- 

 clude many which the British practitioner 

 would place in the first of the foregoing classes, 

 and were adopted with a view of saving the 

 child's life, at an additional risk to the 

 mother. 



The "pelvis oblique ova/a," or obliquely con- 

 tracted pe/vis. This form of pelvic distortion 

 was first distinguished and accurately described 

 by Naegele, the distinguished Professor of Mid- 

 wifery at Heidelberg, as possessing the follow- 

 ing characteristics (seefg. 123.): 



1. _ Complete ankylosis of one of the sacro- 

 iliac joints, with coalescence of the sacrum and 

 ilium, generally leaving no cicatrix nor line of 

 junction. 2. Arrest of development, contrac- 

 tion of the lateral mass, and diminution of the 

 foramina, on the ankylosed side of the sacrum 

 3. Narrowing of the innominate bone of the 

 same side, shortening and also flattening of 

 the linea innominata, contraction of the sa- 

 cro-sciatic notch by the ankylosis, and con- 

 traction of the lateral parts of the sacrum 

 ami ilium composing the sacro-iliac junction. 

 -t. Shifting of the sacrum towards the anky- 



* Essays, p. 354. 



t Traite des Accouchements, p. 457. 



losed side, and twisting of its anterior surface 

 in the same direction, together with removal 

 of the pubic symphysis towards the opposite 

 side, so as to be no longer placed in the 

 median line opposite to the sacral promon- 

 tory, but obliquely directed towards it ; a di- 

 rect forward line from the promontory falling 

 on the superior pubic ramus, between the 

 symphysis and acetabulum, its distance from 

 the former vary ing with the degree of distortion. 

 The bodies of the lower lumbar vertebrae are 

 also.more or less, turned towards the ankylosed 

 side. 5 On the ankylosed side, the inner wall 

 of the pelvis, both before and behind, is less 

 excavated and flatter than in the normal pelvis. 

 6. On the side free from ankylosis also, the 

 form deviates from the normal shape, although 

 at first sight it appears healthy. On placing 

 together the corresponding non-ankylosed 

 sides of two of these pelves, separated at the 

 symphysis and in the median line, in which 

 the right and left sacro-iliac joints respectively 

 were ankylosed, Naegele found the pubic bones 

 widely divergent from each other. So that, 

 on this side also, these pelves are abnormal, 

 not only in direction, but in form also, being 

 curved less behind and more in front, than 

 in the normal pelvis. 7. From this it fol- 

 lows, that the obliquely deformed pelvis is 

 contracted Jn the diameter which extends 

 from the normal sacro-iliac joint to the 

 opposite acetabulum; while it is not con- 

 tracted, but sometimes, according to the de- 

 g'-ee of distortion, even widened in the di- 

 ameter, from the ankylosed joint to the 

 acetabulum of its opposite side. The superior 

 pelvic aperture thus presents the appearance 

 of an oblique oval (or oblong), the longest 

 diameter of which corresponds to one of the 

 oblique pelvic diameters, and the shortest to 

 the other oblique diameter. From this ap- 

 pearance of the brim he was led to apply the 

 name above given. That the sacro-cotyloid 

 distance, and also that between the apex of the 

 sacrum and the sciatic spine, is smaller on the 

 ankylosed side than on the other. That the 

 distances between the sciatic tuberosity of 

 the ankylosed side, and the posterior superior 

 iliac spine of the opposite side, and also be- 

 tween the last lumbar spine and the anterior 

 superior iliac spine of the ankylosed side, are 

 less than the like measurements on the oppo- 

 site side. That the distance between the 

 lower border of the pubic symphysis and the 

 posterior superior iliac spine, is greater on 

 the ankylosed side than on the other. That 

 the walls of the pelvic cavity converge towards 

 the outlet in some degree in an oblique direc- 

 tion, and the sub-pubic arch is more or less 

 narrowed, and turned towards the thigh of the 

 ankylosed side. That the contraction of the sa- 

 crp-sciatic notch, and the approximation of the 

 sciatic spines, is proportionate to the de-n-ee 

 of distortion. And, lastly, that the acetabu- 

 lum of the ankylosed side is directed more 

 forward than normal, and the opposite one 

 almost directly outward. In most cases, the 

 sciatic tuberosity, and the acetabulum of the 

 ankylosed side, were more elevated than the 



