spines as to form a very visible depression). This is less certainty, however, with regard to the ischial tuberosities and the trochanters.

The differences between the two sides must, of course, be considerable (at least one centimètre) if they are to be of diagnostic value. It must also be taken into consideration that after disease of the hip-joint the bones and soft parts may somewhat atrophy.

By means of the signs just mentioned we may, in cases of considerable deformity, establish a diagnosis of oblique distortion of the pelvis ; there are, however, far greater difficulties in deciding upon the degree of the contraction. This varies according to whether the pelvis was originally large or small, and also according to the extent of the dislocation.

An approximate estimate of the degree of deformity can, after all, be obtained when the various methods of examination are adopted which have been detailed above. Naegele's measurements are especially valuable in this respect, and if they show great differences between the two sides we may conclude that the deformity is also considerable. If all the measurements are either pretty large or remarkably small we have a clue as to the original size of the pelvis. The distances between the spines and the crests of the iliac bones are always smaller than the normal.

When there are traces of a previous inflammation we shall know for certain that the oblique distortion is attended by anchylosis. The presence of a synostosis is rendered very probable when the posterior iliac spine of the diseased side is very close to the spinous

process.

It is possible that in a number of obliquely contracted pelves labour has terminated favorably, and that, therefore, the deformity has remained unnoticed; but where attention has been directed to them it has invariably been found that they gave an unfavorable prognosis for both mother and child. Litzmann states that of twentyeight mothers twenty-two died in their first labour, and five of them undelivered; three died in their second and two in their sixth labour. Of forty-one labours six terminated naturally, and five of these occurred in the same woman. Of the forty-one children ten only were born alive (amongst these six by the same mother and two after the Cæsarean section). If we, therefore, do not take into account the woman with the six labours (whose pelvis was larger and only moderately deformed), we find the prognosis to be very

sad.

The prognosis is more favorable when the pelvis was originally roomy. Then, even if the deformity is very considerable, a natural labour is possible; but if smallness of the pelvis is associated with great oblique contraction there is very little hope for the mother, and the child has only one chance, that is when the Cæsarean section is performed early. Breech positions are unfavorable to the child, because the extraction of the head is always very difficult; to the mother, however, they are less so than head positions, on account of the shorter duration of labour.

The mechanism of labour in an obliquely contracted pelvis is of great interest. The position of the promontory chiefly determines the way in which the head enters the brim. It most easily enters with the sagittal suture in the long oblique diameter, when the pro

montory somewhat recedes; but if the promontory projects more into the pelvis it approaches so much the hip-bone of the anchylosed side that the portion of the brim situated beyond the sacro-cotyloid diameter is completely lost for the mechanism of labour, the sacro-cotyloid distance of that side being so small that no portion of the head can enter it. In such a case the brim most resembles that of a generally uniformly contracted pelvis. The head then enters with the occiput very low down, sometimes most easily into the narrow half of the brim, and the sagittal suture then runs in the short oblique diameter. It is evident that, if the pelvis was small originally, and a considerable portion of the brim has been rendered useless for labour, it will not permit at all the entrance of the remaining portion of the head. But even when the head has entered the brim the difficulties of the labour are by no means overcome, for the pelvis becomes narrower in the transverse diameter. The head passes easiest of all through the outlet, with the sagittal suture in the short oblique diameter of the pelvis.

The after-coming head passes more easily through such a pelvis when the occiput is in the wider half.

The treatment depends, first, upon the original size of the pelvis ; and, secondly, upon the degree of the deformity.

If we have the good fortune to recognise this deformity during a first gestation, or if a woman with such a pelvis again becomes pregnant after the successful termination of a previous labour, it will almost always be advisable to induce premature labour. This can then only be dispensed with when the obliquely distorted pelvis of a primipara is unusually large, or when previous labours have shown that even large children may pass through it without danger. The time for inducing premature labour is determined by the size of the pelvis.

If, however, the deformity is only recognised during labour, or in consequence of the impediment which it offers to it, if the head has already entered the brim, we must content ourselves with mere expectancy. As a rule, it will be necessary to shorten labour, and we shall then use the forceps when the child is alive, for it alone is able to save the mother and the child when the head is already in the pelvis.

As delivery is accomplished only by powerful traction, the use of the forceps is consequently attended with great danger. Another disadvantage of the forceps is that it may impede the necessary rotation of the head. When we have come to the conclusion that the head does not descend, even by very powerful traction, it will be the better plan to remove the forceps and to perforate immediately; for under such conditions a child is never born alive, and the prognosis for the mother becomes absolutely unfavorable when forcible traction is long continued; up to the present time in all the cases in which perforation has been performed the mothers have died; but there is little doubt that the operation had been delayed too long. If the child be dead and mechanical difficulties arise we ought to perforate immediately.

If, after the dilatation of the os, the head does not enter the pelvis, this is always so greatly contracted that the Cæsarean section appears to be the best means of delivery. If this can possibly be dispensed

with, or, if the mother objects to the operation, we may endeavour to turn the child. Of course there is little prospect in such cases of delivering the child alive; the sole chance of preserving it depends upon the Cæsarean section. The mother, however, is certainly more benefited by version. If manual extraction of the head is impossible the child dies, and delivery is rapidly effected and with the best possible chance for the mother after the perforation of the after-coming head. It is preferable, however, to perforate the presenting head, whilst it is still moveable above the brim.

E.-The Anchylosed Transversely Contracted Pelvis

This deformity is the rarest of all. Its peculiarity consists in an anchylosis of both sacro-iliac synchondroses. The lateral portions of the sacrum are either entirely absent or only very rudimentary. The sacral vertebræ are small, the sacrum itself is transversely convex instead of concave, and its longitudinal curvature varies according to circumstances. The position of the sacrum also is changed.

It has descended deeply into the pelvis, so as to produce an unusually great prominence of the posterior ends of the iliac bones. The posterior superior spines of the ilia greatly approach each other. The curve of the ilio-peritoneal line is very slight or almost completely absent. The iliac bones proceed from the anchylosed part directly forwards and unite in the symphysis at a very acute angle. The pelvis first described by Robert is symmetrical; in the others which have subsequently been made known asymmetries are found. The dimensions of the pelvis are, of course, greatly altered. The antero-posterior diameter of the brim would be greatly diminished by the descent of the sacrum, if part of that diminution were not counterbalanced by the greater distance between the promontory and symphysis from the want of the transverse extension of the iliac bones. The most important change consists in the great transverse contraction which increases towards the outlet, so as to form merely a long narrow fissure. The transverse diameter of the outlet has been in the cases above referred to from 61 cm. to 24 cm. (2.4-1 inch).

The diagnosis will only rarely be difficult. The distances between the spines and the crests of the iliac bones, and especially between the trochanters, are abnormally small, whilst Baudelocque's

diameter is of almost normal size. We must also examine the posterior surface of the sacrum. If the history shows that the anchylosis has not been preceded by a profuse suppuration we shall find the posterior superior spines of the iliac bones remarkably close to each other, whilst the spinous processes lie so deeply that they can scarcely be felt.

By an internal examination we shall immediately find the contraction of the transverse diameter and the almost parallel course of the descending rami of the pubic bones. The contraction is so great that such a pelvis can hardly be mistaken for any other. From the osteomalacic pelvis it is easily distinguished by the history of the case, by the difference of the posterior surface of the sacrum, by the position of the promontory and of the superior expansions of the iliac bones. The absence of kyphosis and the difference in the transverse diameters of the false pelvis and of the trochanters distinguish it from the kyphotic transversely contracted pelvis. When the transverse contraction is not very considerable there may, however, be some difficulty in distinguishing it from a very small pelvis with a funnel-shaped, transversely-contracted, outlet.

The prognosis is evident from the treatment adopted.

In the majority of the cases the Cæsarean section is the sole rational treatment, even when the child is dead. In seven wellauthenticated cases it has been performed six times. In the gipsy pelvis of Prague, where the transverse contraction was least considerable, perforation and cephalotripsy were sufficient. The woman died of puerperal fever.

Fig. 24 is a copy of the pelvis described by Robert.

.-The Osteomalacic Pelvis

Osteomalacic pelves greatly vary in size, and this variation depends upon the original conditions of the bones. Even very large bones, which have undergone the process of osteomalacic softening, may become much smaller by compression on all sides, and if we can suppose that during such a process the shape of the pelvis is maintained unaltered, a normal pelvis would be converted by osteomalacia into a uniformly contracted one.

Osteomalacic pelves are, moreover, distinguished by their remarkable lightness, although their bones may be thick. The individual bones are strongly bent, and even show infractions. Sections of the bones, as seen in the femurs, show a rarefied, diploë-like tissue, with a compact external osseous layer, which is often very thin. Not infrequently even this has entirely disappeared from parts of the pelvis, and the surface of the bones is rough and porous as if eroded.

The most important changes which take place in the bones are the following:

The sacrum is small, especially in its lateral portions. The vertebral bodies are (as in the highest degrees of rickets) pressed from between the auricular surfaces deeply into the pelvis. Sometimes the downward and forward traction upon the lateral portions of the sacrum produces distinct folds in them. The promontory has sunk

deeply into the pelvis, and nearer to the symphysis and apex of the sacrum. In marked cases the promontory may approach so closely to the apex of the sacrum as almost to touch it, and this is due partly to the altered position of the promontory itself, partly to the consider. able longitudinal concavity of the sacrum. This distinct incurvation,

most frequently situated at the upper portion of the third or even at the second sacral vertebra, is for the most part due to a distinct fracture. The sacral and also the lumbar vertebral bodies are compressed from above downwards and atrophied. By the descent of the promontory the lumbar vertebræ come nearer to the brim. The lumbar lordosis, compensated by a dorsal kyphosis, arches over the brim, similar to what is found in the spodylolisthetic pelvis. The obstetrical conjugate, therefore, lies between the symphysis and one of the last lumbar vertebræ. Scoliosis to any great extent is rare.

The iliac bones are at times small and in some places transparent, but in other cases they may be very thick. The distance between the anterior superior spines is usually somewhat smaller than the normal. The distance between the crests is, as a rule, much greater than that between the spines of the ilia. The iliac bones also show a distinct furrow extending from above downwards, which is sometimes bifurcated. The posterior superior spines of the ilia scarcely project beyond the sacrum; they are small and situated on a level with the spinous process of the last lumbar vertebra. The latter may at times be more prominent, and may also be bent to one side.

The anterior portion of the pelvic ring is compressed from the sides forwards, so that the ilio-pectineal tuberosities approach. The acetabula are directed upwards, forwards, and inwards. The brim is beak-like, pointed at the symphysis. The descending rami of the pubic and the ascending part of the ischial bones, as well as the tuberosities of the latter, have approached each other; usually, however, the latter are turned somewhat outwards. The weakest points become the seat of real incurvations. Sometimes the bones which form the pubic arch or the beak-like symphysis touch each other. More or less considerable irregularities are quite commonly observed in those places.

The dimensions of the pelvis are greatly altered. Usually, the outlet is narrower than the inlet; more rarely the reverse is the

case.