B. Flattened Pelvis.— Is characterized, in particular, by diminution in the antero-posterior diameter of the inlet, the other diameters suffering but little change.
a. Flattened, not Rachitic Pelves.—This variety, according to German writers, is the most frequent of all, 35 to 25 in 100. The general con figuration and the bones of such women are frail. The sacrum is usually deeply placed between the iliac bones, projecting forwards, and the pos terior iliac spines jut out considerably beyond the sacrum. The inclina tion of the sacrum, however, seems less, perhaps, than normal. Exter nal mensuration gives figures a little below the normal. The external con jugate is the most diminished, while the transverse are but little altered. The distance between the anterior and the posterior iliac spines is dimin ished. The deduction to obtain the true conjugate is about the same as in the normal pelvis. This diameter is usually over three inches, and rarely below. Sometimes there exists a double promontory.
b. Flattened, Rachitic the diameters are lessened, particu larly the antero-posterior. This is the most frequent of all pelves. The diagnosis is easy. The hips are narrow, the distance between the crests and the spines is diminished. The sacrum has the rachitic shape, the anterior and posterior spines are near together, the external conjugate is notably diminished. The inclination of the symphysis is great, and therefore great deduction must be made to obtain the true conjugate.
C. Oblique, Oval diagnosis has only exceptionally been made on the living. Its presence may be suspected by the greater ele vation of one of the iliac crests, by the inequality of the distance between the anterior and posterior iliac spines and the spinous process of the last •lumbar vertebra. The posterior iliac spine is on the anchylosed side nearest the median line. The symphysis is found to be directed towards one of the sides, the ischiatic spines are at about the same distance from the sacrum, and one of the sacro-cotyloid diameters is shorter than its fellow. According to Naegeli., the following measurements are obtained by Baudelocque's pelvimeter: Inches.
From the isch. tuberosity one side to the post. ant. spine of the other, mean distance . • 6.8 From the ant. sup. spine of one side to the post. sup.
spine of the other, 8.19 From the spinous process of the last lumbar vertebra, to the ant. sup. spine of both sides, . 7.02 From the trochanter of one side, to the post. sup, spine of the other, 8.58 From the centre of the inferior border of the symphysis to the post. sup. spine of each side, . 6.8 The prognosis is very grave. Litzmann, found that of 28 women, 22 died at first confinement, 5 at the second, and 1 at the sixth. Of 41 de liveries only 6 were normal, and of these 6, 5 were in the same woman.
Of 41 children, only 10 were. born alive, 6 from the same woman, and 2 by the Cesarean section. Schroeder, however, in 3 cases, notes all the mothers and children living.
Thomas lays down the following corollaries: " A. We must always think of the oval pelvis when: 1. Some mechanical cause seems to inter fere with labor, even though we cannot reach the promontory; 2. When the iliac crests are not on the same level; 3. When the two postero superior iliac spines are at unequal distances from the sacral crests; 4. When the history tells us that in infancy there was disease of the pelvic bones. B. When we suspect an oblique narrowing of the pelvis, we must endeavor to reach a diagnosis by: 1. Palpating the horizontal pubic rami, and the internal lateral walls of the pelvis; 2. Measuring the posterior stheno-cords. (Ritgen.); 3. External measurements, which often alone suffice." D. Transversely contracted Pelvis.—The diagnosis is easy, since there exists marked narrowing of the inferior strait. The parallelism of the pubic rami is striking, the narrowness of the symphysis, the nearness of the ischiatic tuberosities. External mensuration allows us to determine notable diminution in the following diameters:1. Between the trochanters.
2. Between the two iliac crests.
3. Between the ant. sup. iliac spines.
4. Between the ischiatic tuberosities.
E. Scoliotic, Kyphotic Pelvis.—The deformity of the vertebral column will at once attract attention.
F. Spondylolisthesic Pelvis.—The history will reveal an injury after infancy. The attitude is often characteristic, owing to the forward in flection of the vertebral column. In Olshausen's case the woman walked like a quadruped; in Belloc's, the head and the upper part of the trunk were inclined forward to the level of the pelvis. The thorax is pushed backward, and the distance between it and the pelvis is notably diminished. Internal examination allows us to touch readily all the bony portions. Externally the spinal curve, with concavity backwards, is noticeable.
G. As for pelves deformed by luxations, shortening of the inferior limbs, the nature of the lesion is apparent. We may, however, be deceived. We remember a case where there existed a congenital luxation of the right femur, and yet on vaginal examination very different characters were found. On close questioning we elicited the fact that, in childhood, the woman had suffered, in addition, from caries of the upper part of the sacrum and lower lumbar column.
H. The osteomalacic pelvis does not entail any difficulty in diagnosis. The progressive march of this disease; its beginning after repeated preg nancies, and the peculiar form of the deformity will put us on the right track.