Asa general rule, whatever the appearance or health of the woman, the pelvis should be examined with care.
Palpation, at the seventh month, will ordinarily allow us, in primiparie, to judge as to the engagement of the fetal head. If engagement has not occurred, then should the pelvis be examined with care. In multiparte we possess the data furnished by previous deliveries. We know that deformity of the inferior strait and of the cavity is usually due to kypho sis. The deviation of the spine, therefore, will arouse our suspicions.
Signs of are obtained from direct examination of the pelvis. The following are, according to Cazeaux, the normal dimensions of the pelvis.
Instrumental Pelvimetry.
Pelvimetry may be external, or internal. The number of instruments is great. In 1856, Killian, in his Armainentarium Lucitue, described 20, and this number has greatly increased. The oldest instruments .are those of Stein, 1770, and of Baildelocque, 1781. We mention simply the principal ones. For the description of each the curious reader is referred to Lenoir's monograph.
Of external pelvimeters, we mention, Baudelocque's and Davis'; of in ternal, Stark's, Kurzwich's, Koppe's, Simon's, Asdrubali's, Wigand's, Weidmann's, Ritgen's, Osiander's, etc., etc.; of the combined, Boivin's, Beck's, Amant's, Lazarevitch's, Kiwisch's, Veit's, Hubert's, Budin's, etc., etc. We will describe simply the pelvimeters of Baudelocque,Van Huevel, Depaul, Budin, Hubert, Kuestner, Crouzat.
Baudeloegues consists of two metal rods curved into a half circle so as to embrace, in their concavity, the greater part of the pelvis. The ends of the rods are furnished with lentil-shaped buttons, for application to the ends of the line we wish to measure. A graduated bar is fitted at the junction of the straight and curved portion of the in strument, and thus the degree of separation of the extremities is measured.
Van Huevel's in 1841, modified in 1855, we de scribe it as completed. It is a compass in shape, composed of two blades; the one fixed, the other movable. The first is internal or vaginal, and is eleven inches long, flattened like a spatula at its end, furnished at the centre with a ring below; this a graduated circle, and it articulates below, like a compass, with the second blade. This, in turn, may be shortened
or lengthened at will, by sliding downward or upwards. (See Fig. 94.) Its upper extremity is traversed by a screw. When in use, the internal blade rests, at its extremity, at the sacro-vertebral angle, for internal measurements, and for external the extremities of the blades are used even, as in Baudelocque's instrument. The essential part and advantage of the instrument is the fact that the external blade is movable upward or downward with ease, and therefore the measurements may be very exactly obtained. The extremity of the internal blade may further be placed on the inner border of the symphysis, or indeed at any internal point, the outer blade resting wherever we please, and thus we may obtain the thickness of the symphysis, or any one of the diameters with a considera ble degree of accuracy.
Depaul's Pelvimeter.—This is simply Baudelocque's, modified so as to allow of its being used internally. The two blades of the instrument form, not a half circle, but a figure of eight, and further they may cross one another. (Fig. 95.) A supplementary movable blade allows of measuring the height of the uterus, one of the shorter blades resting on • the cervix.
Budin's Cephalometer. (Fig. 96.)—In principle it is simply Depaul's pelvimeter enlarged. It is 17.7 inches long; the two blades may be op posed and slide on one another, each being 9.75 inches long. One blade holds a graduated circle, the other terminates in an index. When the two extremities are in contact, the index points to 0, and as they separate this index marks the degree.
Hubert's Pelvimeter. (Fig. 97.)—In shape like a widely open V, the long external blade is 6.5 inches long, and curved at its lower extremity, at an angle of 45°, to join the second blade, which terminates in a spatula, 2 inches long, and 1 broad. To complete the instrument, take a piece of letter paper, and fold it 7 to 8 times on itself, and cut it to a point. (Figs. 98, 99.) Method of Usinq.—Tito highest point of the external surface of the pubes is marked. The vaginal blade is then guided to the moral prom ontory by the finger; the point of the paper is placed at the mark on the pubes, and the other end passed through and held in the second blade.