184 



PELVIS. 



of the sacrum is more open than usual. Thus 

 is constituted another variety of funnel-shaped 

 pelvis, caused mainly by the gradually nar- 

 rowing of antero-posterior diameters, instead 

 of the lateral, as in the masculine pelvis be- 

 fore described. 



In the King's College Museum are the pelvis 

 and spine of a female, well exemplifying this 

 deformity (see/^. 1 16.). The spine is affected 

 by a rickety curve, the greatest extent of 

 which is about the Gth, 7th and 8th dorsal 



Fig. 116. 



Oblnng pelvic deformity. (From a preparation in the 

 Museum of King's College.') 



vertebra (a), directed backwards to a great 

 extent, and somewhat to the left side, with a 

 compensatory curve to the right, at the junc- 

 tion of the lumbar with the dorsal vertebrae 

 (I)). The lower lumbar vertebrae and sacral 

 promontory are twisted considerably towards 

 the left side, and dragged backwards, the sacral 

 promontory being also considerably raised up- 

 wards (c). The pelvis is of exceedingly large 

 general capacity, and otherwise well formed, 

 showing evidently, by the preponderance of 

 the conjugate diameter and appearance of 

 the sacrum, the effect of the deformed spine 

 upon it. The conjugate diameter of the brim 

 measures as much as 5 and a half inches ; 

 the transverse 5i inches. At the outlet, the 

 distance between the tuberosities is only 3|- 

 inches, and the sub-pubic angle 75 ; but, 

 from an unfortunate deficiency of the lower 

 end of the sacrum, the antero-posterior 

 diameter cannot be measured. 



In the same Museum there is a young male 

 adult skeleton in which this form of pelvis 

 is also well shown. It, also, is coexistent 

 with, and dependant on, a backward cur- 

 vature and shortening of the spine, and ex- 

 tensive ankylosis of the vertebras in the 

 dorsal and lumbar regions. The lumbar ver- 

 tebras are inclined much backward, so as to 

 drag in the same direction upon the upper 



end of the sacrum ; while the upper dorsal 

 vertebras incline forward, so as to bring the 

 1st dorsal over the centre of the pelvic circle. 

 There is, in this case, no lateral deviation of the 

 spinal column. The tibia? and fibulae have an 

 inward curve, indicating the existence of a 

 softened rickety state of the bones at an 

 early period of life. 



In the Hunterian collection of pathological 

 specimens is a young adult pelvis, numbered 

 3iXO, presenting the same kind of deformity, 

 accompanying the same kind of backward 

 angular curvature and ankylosis of the bodies 

 of the vertebras at the same place viz. the 

 junction of the last dorsal and 1st lumbar. 

 The 1st dorsal vertebra, in this skeleton, 

 likewise occupies a position above the centre 

 of the pelvic opening. The upper end of the 

 sacrum is dragged backwards by the inclined 

 lumbar vertebrae so as to increase the con- 

 jugate diameter of the brim to 4J inches. 

 The lower end of the sacrum is tilted forward 

 so as to bring the tip of the coccyx to within 

 a short distance of the ischial spines. The 

 cotylo-sacral arch is stretched out, and the 

 transverse diameter of the brim reduced to 

 4 inches only. The acetabula are directed 

 more downwards than usual, and the right 

 iliac wing is pressed outwards by the 9th and 

 10th ribs, which rest on it, and the venter 

 completely flattened out. 



I find that Rokitansky has met with in- 

 stances of this oblong deformity of the pelvis, 

 coexisting with backward angularity of the 

 spine. 



In cases of backward angular curvature 

 low down the spine, especially where there 

 is no lateral deviation, there will be a 

 tendency to production of this form of pelvis, 

 especially if the bones be somewhat softened, 

 as they usually are in these cases ; and al- 

 though such cases of pelvic distortion are, 

 as far as I have seen, more common in the 

 male, yet the same cause occasionally produces 

 this effect upon the female pelvis, and may 

 produce obstruction during parturition, not 

 only by the contraction of the antero-posterior 

 diameter at the outlet, but even at the brim, 

 by the diminution of its transverse diameter. 



An acute angle in the lower part of the 

 sacral curve may also produce this contraction 

 of the inferior pelvic outlet. When this exists 

 singly, the elevation of the coccyx is more 

 considerable than usual, and the axis of the in- 

 ferior plane directed more backwards. This 

 bending upwards of the apex of the sacrum is, 

 however, most usually seen in connection with 

 more general pelvic deformity, and is some- 

 times accompanied by ankylosis of the sacro- 

 coccygeal joint. 



In a case recorded by Mr. Bell, the antero- 

 posterior diameter of the inferior outlet was 

 contracted to half-an-inch only, and in one 

 of Naegele's, it was even less than this, in 

 both entirely precluding delivery. In so great 

 a contraction, the sacral bend must have been 

 unusually great, or the lower end of that 

 bone tilted forward in the manner just de- 

 scribed. 



