2. At the inlet, the greatest enlargement occurs in the transverse diam eter. The reverse obtains at the outlet. The longitudinal diameter is less elongated than the transverse.
3. To produce enlargement of the superior strait, almost double the force is necessary as for the inferior strait.
4. The elongation of the transverse diaineter of the inlet involves the shortening of the conjugate. However, the elongation of the conjugate does not modify the transverse diameter (in some cases we obtain a short ening of about one twenty-fifth of an inch).
5. The maximum elongation of the transverse diameter of the inlet always slightly enlarges the conjugate. But the maximum elongatiqp of the conjugate does not, generally, enlarge the transverse diameter.
6. The simultaneous enlargement of both diameters of the inlet never elongates them so greatly as a successive enlargement of each diameter.
7. The widening of the outlet always slightly shortens the conjugate, and slightly elongates, or leaves intact, the transverse cliameter of the superior strait.
8. The same holds true of the outlet when the inlet is widened.
9. In,most of our cases we noticed greater mobility in the ligaments of the sacro-iliac and sacral articulations.
10. In the most mobile joint,s, the quantity of synovia was always in creased.
11. The elongation of the longitudinal diameter depends on the mo bility of the sacrum, but the mobility of the symphysis particularly aids increase of the transverse diameter.
12. The larger the crevice or cavity of the symphysis pubes, the greater the mobility of this articulation.
13. The number of labors seem to have no influence upon the mo bility of the pelvic articulations.
Causes.—The temperament of the patients has been mentioned as a cause. Feeble and delicate women are supposed to be more predisposed than others (Munro, Smellie), and Roederer has even said that debility, rickets, venereal diseases and profound cachexile were themselves capable of producing relaxation of the pelvic ligaments. Morgagni opposed this exaggerated opinion. The influence of scrofula is not more manifest. Other assumed causes are extreme youth or age of the women, and the primiparous and multiparous condition. The contradiction of these opinions deprives them of value. Jacquemier holds that the relaxation of the symphyses is due to the development of the uterus, particularly when this development surpasses ordinary limits, as in large size of the fo3tus, twin pregnancy and hydramnion. (But there are cases in which the relaxation appeared in the second or the third month.) Excessive exercise, bodily fatigue and anchylosis of the knee are causes. Too sudden getting up after confinement has been accused of an etio logical relation.
All these causes are problematical, for one observes relaxation of the articulations in women belonging to all classes of society, and the eti ology is, really, very obscure.
Relaxation of the symphysis always begins during pregnancy, and, in general, in the seventh, eighth and ninth months, but it may commence much earlier. Moreau has seen it in the second month and Desormeaux in the fifth. In two cases of our own, the disease began once at six
months and once at seven and a half. The disease always begins insidi ously, by a feeling of lassitude and weakness, accompanied by pains in the 'lumbar region, which, at first dull, soon grow more intense, and in volve the buttocks, the groins, and the symphysis pubes. The patients at first only feel them when walking, then in the standing or sitting pos ture, and, finally, in some cases, they become so pronounced that they do not cease even when the patients assume the dorsal decubitus, and the least movements become so painful as to be almost impossible. The pains are always more marked at the sacro-iliac joints than at the pubic symphysis. They are often accompanied by numbness in the abdomen. When the patients rise, the pains become very violent and assume a peculiar character. It seems to the women as if the pelvis WWI spreading apart, their bones becoming dislocated, and as if they were sinking between their haunches. The gait becomes almost pathognomonic. It consists in a balancing from one leg to the other, a sort of oscillation. The women waddle like ducks. In walking, the women sustain their loins with their hands, now bending forward and now backward. At such times we can feel the bones being displaced, and when we attempt to make them move upon each other, the woman resting on her back, this is successful up to a certain point. If we feel of the different joints, we excite a sharp pain in them, and sometimes can observe a notable dis placement of the bones at the symphysis pubis. Trousseau related a case where one could introduce the end of the finger. When the sepa ration is not appreciable to the touch, we may recognize it by a proceed ing which we often saw used by Depaul before Budin again called atten tion to it at the Biological Society. It consists in placing the woman in the erect posture, against a resisting object, and in placing two fingers horizontally beneath the symphysis and therefore introduced a little way within the vagina. The woman is now made to stamp the feet or to walk a few steps, whereupon the fingers applied below the symphysis, distinctly feel the oscillation of the iliac bones at this level, and thus ascertain the mobility and the widening of the articulation When once begun, the relaxation of the joints goes on increasing until the time of delivery, but if the women keep quiet, they only have their movements impaired; their general health is unaffected. It is not always thus, for in one of our cases the pain was such as to deprive the patient of sleep, and thus to induce notable weaknegg and exhaustion. Generally, this articular relaxation disappears after labor, but sometimes it persists at least a short time, and, rarely, for months or even years. Courty quoted a case which lasted two years, and Baudelocque one of nine months' standing. Lenoir and Robert have seen the malady persist through life. In one of our cases the duration was eighteen months.