Part 22 (1/2)

[Ill.u.s.tration: _From_ Naegele.]

[Ill.u.s.tration]

_Malacosteon_, or _mollities ossium_. An arthritic, rheumatic, or gouty diathesis is a morbid state, in which softening of the bones may take place at a much later period of life, and to a most extraordinary extent.

In almost all the cases of extreme pelvic deformity which have been recorded, the distortion has been owing to this disease, and not to rickets in early life: in a pathological point of view there is a considerable a.n.a.logy between these two diseases. From a variety of causes there is a superabundant formation of acid in the system, which its excreting organs are unable to throw off. The effects of this condition will vary according to circ.u.mstances; among them the softened state of the bones from a deficiency of insoluble bone earth is not the least remarkable. Mollities ossium seldom attacks women who have had no children: sometimes it begins shortly after delivery, and very frequently during pregnancy, during the progress of which it continues to increase.

Hence, it occasionally happens, that a woman has given birth to several healthy living children without any unusual difficulty in her labours, and where, after this, the pelvis has gradually become so deformed from mollities ossium, as to render delivery impossible by the natural pa.s.sages, and, therefore, to require the Caesarean operation. Pelves of this sort, may be easily distinguished from those which have been deformed in early life by rickets; they have evidently attained their full adult growth before the process of softening had commenced: the ilia, for instance, are of the natural size, but bent across, as if they had been folded like wet pasteboard; whereas, the bones of the ricketty pelvis have not attained their full development, they are stunted in growth as well as distorted in shape, the two processes, viz. of growth and distortion, having evidently, co-existed.

The form of the pelvis in mollities ossium necessarily varies with the peculiar circ.u.mstances under which the individual is placed: thus, if her strength allows her to sit up, or even to get about, as is generally the case more or less, the promontory and the pubic bones are gradually pressed towards each other, so that the antero-posterior diameter is greatly diminished:[123] if, however, she is confined entirely to bed for a considerable period, the distortion takes a different and much rarer form. From her lying first on one side and then on the other, the pelvis is laterally compressed; the transverse diameter becomes even shorter than the antero-posterior; and if the disease continues long enough, the pelvis is at length so altered and mis-shapen, that nearly all its original configuration is obliterated. The weight of such a pelvis varies considerably: where the disease has ceased some time before death, and bone earth has been again deposited, there will be little difference in this respect from a natural healthy pelvis; but if the patient has died with the disease in full activity, its weight will be greatly diminished, amounting sometimes only to a few ounces.

Mollities ossium, to a slight extent, we believe, is not very uncommon, although cases of extreme deformity from this cause are of rare occurrence. Mr. Barlow states, that ”eight cases of this species of progressive deformity have fallen under my notice, in one of which the projection of the last lumbar vertebra at its union with the angle of the sacrum was so much bent forwards into the cavity of the pelvis, that on the introduction of the fore-finger up the v.a.g.i.n.a, a protuberance was presented to the touch very much resembling the head of the foetus pretty far advanced into its cavity. On carrying the finger a little anteriorly past the projection, I could with difficulty ascertain the head of the child: but on moving it around, the distortion appeared so great, that the whole circ.u.mference did not exceed that of a half-crown piece. This occurrence was on the 29th of April, 1792, at which time I delivered the woman with the crotchet, and the bones of the pelvis receded considerably to the impulsive efforts during the extraction of the head of the foetus; yet, notwithstanding, the flexibility of the bones of the pelvis, and the debilitated state of her const.i.tution, she recovered speedily and without interruption.” On the 2d February, 1794, being in the neighbourhood, and learning that she was still alive, Mr. Barlow visited her and requested an examination. ”I found her unable to walk without a.s.sistance, and as she sat, her breast and knees were almost in contact with each other. The superior aperture was nearly in the same state as when I delivered her with the crotchet, but the outlet appeared more contracted, the rami of the p.u.b.es overreached, leaving a small opening under the symphysis barely sufficient to admit the finger to pa.s.s into the v.a.g.i.n.a by that pa.s.sage, and another aperture below, but rather larger, and parallel with the junction of the tuberosities of the ossa ischii. From what I learned afterwards respecting this decrepit female, she survived this period about two years, at which time she was become still more distorted in the spine; and after her death it was with difficulty she could be put into her coffin; this woman bore nine children, and died in the thirty-ninth year of her age.” (Barlow's _Essays_, p. 329.)

Mollities ossium may be feared when, in addition to the general breaking up of the health and strength, the patient suffers from arthritic pains and swellings of the limbs, the urine is generally loaded with lithic secretion: and most of all, where distinct shortening and gradual distortion of the skeleton is taking place. Where the deformity has been the result of rickets in early life, a little careful observation of the patient's external appearance will quickly lead the experienced eye to suspect the nature of the case.

_Symptoms of deformed pelvis._ Among the external appearances which would lead us to suspect a deformed pelvis, are ”the lower jaw projecting beyond the upper; the chin very prominent; the teeth grooved transversely; unhealthy appearance; pale ashy colour of the face; diminutive statue; unsteady gait; when the woman walks the chest is held back, the abdomen projects, and the arms hang behind; there is deformity of the spine and breast, one hip higher than the other, the joints of the hands and feet are remarkably thick; curvature of the extremities, especially the inferior, even without distortion of the spine is a very important sign; wherever the lower extremities are curved, the pelvis is mostly deformed: it is well to ascertain also if, when a child, it was a long time before she could walk alone; whether she had any fall on the sacrum; whether as a girl she was made to carry heavy weights, or to work in manufactories.”

(Naegele's _Lehrbuch_. -- 444.)

_Funnel-shaped pelvis._ Besides the above-mentioned species of pelvic deformity, others are occasionally met with, the origin of which is but little understood. The funnel-shaped pelvis is of this character, where the brim is perfectly well formed, but where it gradually contracts towards the inferior aperture. There are no evidences of its having been produced by any disease; nor in fact can we a.s.sign any satisfactory cause for this peculiar configuration: it appears to have been a congenital formation.

[Ill.u.s.tration]

_Obliquely distorted pelvis._ A still more remarkable species of pelvic deformity is the _pelvis oblique ovata_, which, of late years, has been pointed out by Professor Naegele. In this case the pelvis appears awry, the symphysis pubis being pushed over to one side; and the sacrum to the other; one side of the pelvis is more or less flattened, the other bulges out, so that one oblique diameter is shorter, the other longer than natural; and this applies not only to the brim, but to the cavity and outlet of the pelvis. In most cases the sacro-iliac symphysis on that side which is flattened, and to which the sacrum is inclined, is completely anchylosed, not a trace of the division between the ilium and sacrum to be detected, the two bones being completely united into one. In many, the sacrum on this side is smaller than on the other, as if a portion of it had been removed by absorption during the process of anchylosis, or at least not properly developed. When we consider the form of the pelvis, and the appearances which the sacro-iliac symphysis and the sacrum present, we are almost led to conclude that ulcerative absorption must at one time have existed between the sacrum and ilium at this point, probably at an earlier period, by which means more or less bone had been destroyed before the termination of the disease in anchylosis; indeed, we can to a certain extent imitate this peculiar species of pelvic deformity by sawing off the surfaces of the sacrum and ilium which had formed the symphysis, and then putting the bones together again. Still, however, in the various cases which have been collected by Professor Naegele, no proofs could be obtained of disease having existed in the pelvis during early life.

”In none of the cases, the particulars of which have come to my knowledge, has there been any trace of rachitis; nor have any of the symptoms, appearances, and morbid changes been observed which characterize mollities ossium coming on after p.u.b.erty. None of these cases have been traced to the effects of external violence, as falls, blows, &c.; nor has there been any complaint of pain in the region of the pelvis, inferior extremities, &c.” (_Das Schrag Verengte Becken_, p. 12.) ”With respect to the strength, colour, structure, &c. of the bones of this species of deformed pelvis, no difference could be observed between them and the bones of young and perfectly healthy subjects; not a trace either in form or other respects could be detected of those changes which usually result from rachitis or mollities ossium; and but for this distortion and some other slight irregularities, which required close inspection to detect, these pelves would have been looked upon as well-shaped, and of sufficient capacity.” (Naegele, _op. cit._ p. 11.) In some specimens no trace of anchylosis at the sacro-iliac symphysis has been observed; but whether this was the case throughout the union of the two bones we cannot say.

Professor Naegele is inclined to look upon them as modifications of the _pelvis oblique ovata_, and certainly in the majority of known cases anchylosis has been found present.

It is scarcely necessary to do more than enumerate other varieties in the form of the pelvis, which are occasionally met with: it is sometimes round, the transverse and antero-posterior diameters being of the same length; in other cases it possesses many of the characters which distinguish the male pelvis, being more or less triangular, deep, and with a contracted angular pubic arch.

_Exostosis._ Lastly, the pelvis may be perfectly well formed, but the pa.s.sage through it more or less interrupted by the exostosis: this is, perhaps, the rarest species of dystocia pelvica. It may arise from wounds of the periosteum, from fracture of the bones, callus, &c. and may vary in size from a small protuberance to a large ma.s.s, which completely fills up the pelvis.

_Diagnosis of contracted pelvis._ The difficulty of detecting an abnormal configuration of the pelvis, will depend, in great measure, upon its extent: where it is but slight, it may easily be pa.s.sed over un.o.bserved by a young pract.i.tioner, although it may, nevertheless, be quite sufficient to render labour both difficult and dangerous. In the ordinary form of contracted pelvis, where the antero-posterior diameter is shorter than natural, the being able to reach the projecting promontory of the sacrum with the finger is of itself a sufficient evidence: but the converse of this is not true, for we frequently meet with cases of contracted pelvis, without being able to reach the promontory. The numerous instruments which have been invented at different times for measuring the pelvis are of such doubtful accuracy, as to be nearly useless; the experienced finger is the best pelvimeter; and the power of correctly estimating the dimensions of the pelvis during examination, can only be acquired by constant practice, based on a thorough knowledge of them in the healthy pelvis.

The manner in which labour commences is frequently sufficient to make us suspect the presence of a contracted pelvis. Besides, the general appearance of the patient, we frequently find that the uterine contractions are very irregular; that they have but little effect in dilating the os uteri; the head does not descend against it, but remains high up; it shows no disposition to enter the pelvic cavity, and rests upon the symphysis pubis, against which it presses very forcibly, being pushed forwards by the promontory of the sacrum. It is probably from this circ.u.mstance that the os uteri, more especially its anterior lip, shows so little disposition to dilate in these cases, for the lower portion of the uterus being jammed between the head and symphysis pubis in front, and promontory behind, the contractions of the longitudinal fibres can have little effect upon the os uteri. Hence we find, that in cases of diminished antero-posterior diameter requiring perforation, and where the os uteri in spite of violent pains, bleeding, &c. has refused to dilate beyond a certain point, on lessening the head, and thus removing its pressure from the symphysis pubis, it has quickly attained its full degree of dilatation.

Where the pains have been active, and a portion of the head has forced itself through the brim, and now projects to a certain extent into the cavity of the pelvis, it will be still more difficult to reach the promontory before delivery; and if, as is frequently the case, the sacrum is bent strongly backwards, so as to render the cavity and outlet very s.p.a.cious, the real cause of impediment to the progress of labour may be entirely overlooked. It is here that the position of the head upon the symphysis pubis will prove a valuable means of diagnosis. The straightness of the sacrum will also be a guide in other cases.

In that form of the pelvis which has been called the funnel-shaped pelvis, and where the brim and upper portion of the cavity are of the natural dimensions, but where it gradually diminishes towards the outlet, the appearances are frequently very deceptive, the head advances without impediment, and descends as far as the inferior aperture, with every promise of speedy delivery; but here its progress is arrested, and even in the very last stage may require perforation.

It occasionally happens, also, where the deformity is very considerable, that the promonotory projects to such an extent as to be even capable of being mistaken for the head itself; and cases have actually occurred where, under this impression, the bone has been perforated instead of the child's head. So gross an error as this may easily be avoided by care in making the examination; by ascertaining that the projecting ma.s.s is immoveable; that the patient is sensible to the pressure of our finger; and that the promontory can be traced to be continuous with the adjacent parts of the pelvis.

The effects which may result from labour protracted by pelvic deformity are very various, both as regards the mother and her child. The most common form of injury which is produced by this cause, is the contusion and consequent inflammation and sloughing of the soft tissues which line the pelvis from the long continued pressure of the head against the symphysis pubis in front, and against the promontory of the sacrum behind.

Not only may sloughing of the v.a.g.i.n.a and lower part of the uterus be the result, but the mischief may extend through the posterior wall of the bladder, and thus render the patient incapable of retaining her urine, and an object of great, and, generally speaking, incurable suffering.

The danger from rupture of the uterus will chiefly depend on the degree of pressure with which the uterine contractions force the head against the brim. Where the pains are violent, and yet insufficient to overcome the obstacle which the contracted pelvis presents to the advance of the head, there is not safety for a minute, and perforation must be immediately had recourse to. Where the edge of the promontory is very projecting and sharp, the structure of the uterus may be seriously injured by the pressure and contusion. In some cases it has evidently been the cause of ruptures, the fibres having given way first at this spot.

The constant severe pressure upon the head will be not less injurious to the child's life; it must inevitably produce a considerable impediment to the cerebral circulation; and where the liquor amnii has escaped, the pressure of the uterus upon the body of the child will scarcely be less prejudicial. The cranial bones frequently become remarkably distorted, so that after a difficult labour a deep furrow is found on that part of the head which corresponded to the projecting promontory.

_Fracture of the parietal bone_ may even be produced, a fact of which pract.i.tioners, till lately, have not been sufficiently aware; and cases have occurred where children have been born dead, with the head greatly distorted, and one of the bones fractured, from which circ.u.mstances the mothers have been suspected of infanticide. Dr. Michaelis, of Kiel, has lately reported an interesting case of this kind, where the fracture seems to have resulted from the great immobility of the coccyx. The head was much disfigured, and on examining it the frontal bones were uninjured, but so flattened that the frontal and parietal portions of the sagittal suture lay nearly in the same place; the fontanelle and anterior two-thirds of the sagittal suture projected high up, and the sagittal borders of the parietal bones were firm and well formed. In the posterior third of the sagittal suture, where the parietal bones were firm and well formed, and the suture only two lines in width, were seen small livid portions of the longitudinal sinus forced between the bones. The occipital bone was flattened and forced deep under the parietal bones, but not otherwise injured. The right parietal bone, which during birth had been turned towards the promontory of the sacrum, was covered anteriorly and superiorly with effused blood, and on removing the periosteum, was found fractured in five places. (_Neue Zeitschrift fur Geburtskunde_, vol. iv.