the brim or outlet.
Vertical flatness of the sacrum, or want of
the proper vertical curvature, is occasionally
met with, according to Dr. Churchill, after
whom the annexed engraving of a specimen of
this deformity is taken (fig. 115.). This is
Fig. 115.
Flatness of the sacrum, and contraction of the pelvic
cavity. (After Churchill.}
sometimes accompanied by an increased sacro-
vertebral angle. One or two instances I have
met with, in which there was a tendency to
this peculiarity. It is attended with diminu-
tion of the antero-posterior diameter of the
cavity, and is most frequently met with in
cases of general ovate deformity.
The opposition it would offer to the passage
and circumvolution of the foetal head is evi-
dent.
An inward projection of the sciatic spines
is often seen in connection with contraction of
the transverse diameter of the inferior outlet,
without any inordinate massiveness or mascu-
line form of the pelvis, as in the example be-
fore mentioned, and is, probably, sometimes
dependent on the same cause viz., the action
PELVIS.
183
of the great glutei muscles upon softened
ischia. In some instances, however, this length
and projection of the spines cannot be thus
accounted for. Obstruction may occur before
the head reaches the tuberosities in these cases.
Their relative positions may be altered also by
fracture.
Pelves in which the cavities are contracted
at the lower part by disease, present the chief
obstacles at the interior outlet, and will be
considered under that head.
A variety of the shape of the pelvic cavity
is mentioned by Murphy, as forming a contrast
to the funnel-shaped masculine pelvis. It is
the funnel-shaped reversed by the gradual wi-
dening of the transverse diameters downward ;
but, being generally attended by some contrac-
tion at the brim, it belongs rather to the classes
of deformities before described, and would
seem to resemble the first case of Ramsbo-
tham's there cited, and to be the beginning of
a more complete ovate deformity, afterwards
to be mentioned, as shown by the widening of
the inferior opening.
Distortions affecting the outlet only or prin-
cipally. In these cases the greatest obstruc-
tion occurs at the inferior outlet, which, being
comparatively independent of the brim and
cavity, may be contracted without any im-
portant alteration in their shape or size.
Contraction of the transverse diameter is
the most frequently seen. The ischial tube-
rosities are approximated, and the space of
the sub-pubic arch lessened ; and thus, indi-
rectly, the antero-posterior diameter is ren-
dered less effectual. Cases are frequently
presented to the obstetrician, and many are
on record, in which obstruction has occurred
at the sciatic tuberosities, and the use of the
forceps been rendered necessary. The normal
distance between the centres of these processes
is from 4 inches to 4^. In my measurements
I have met with as small a distance as 3f
inches in female pelves, in which the trans-
verse diameters were generally rather small.
The bi-parietal diameter of the fcetal head
is said to be 3^ inches, and is placed obliquely
between these tuberosities, as the occiput
emerges under the sub-pubic arch. The
soft parts, besides, will occupy at least thiee-
fourths of an inch. Thus wiih a large
and well-ossified head and contracted inter-
tuberal distance, the impediment is great.
The diminished span of the sub-pubic arch,
also, pushes back the head upon the coccyx,
and renders a greater enlargement than usual
of the antero-posterior diameter necessary ;
while at the same time the great sacro-sciatic
ligaments are also approximated and rendered
extremely tense, and thus the oblique di-
ameter between them and the ischio-pubic
rami is also considerably diminished.
The special cause of this deformity, when not
dependent upon the infantile, masculine, or
funnel-shaped pelvis before described, is to
be attributed to the action of the great glutei
muscles, in standing and walking, pressing
upon the ischia partially softened by disease.
Contraction of the antero-posterior diameter.
This results in most cases from anl-ylosis
of the sacro-coccygeal joint. The coccyx is
rendered immoveableand incapable of yielding
to the head of the fetus, so as to bring about the
usual increase in the antero-posterior diameter.
In addition, it is usually ankylosed in an
almost horizontal direction, with its apex
directed forwards and its surfaces upwards
and downwards, a position which is brought
about by the resiliency of the sacro-sciatic liga-
ments and ischio-coccygeus muscles, and by a
continued sitting posture ; and thus the an-
tero-posterior diameter is still more diminished.
The foetal head is arrested by, and rests on,
the coccyx, and the obstruction is only over-
come by the giving way of the bone at or
near the ankylosed part. The delivery gener-
ally requires instrumental aid.
Examples of this condition are nume-
rous. In the practice of Dr. Michaelis of Kiel,
a fracture of the parietal bone of the infant
was occasioned by an immobility of the coccyx
resulting from ankylosis.* Dr. Merriman, in
a Letter to Dr. Lee, published in the Med.
Gazette (1843, p. 224.), mentions a casein
which the point of the coccyx snapped off in
three successive labours, and he had observed
one or two other cases in which this occurred,
and no ill consequences followed. In one,
the coccyx was turned upwards, and there
was a considerable bulk of ankylosis, pro-
duced by a fall. Dr. F. Ramsbotham also
mentions three instances in which fracture
at or near an ankylosis of the coccyx took
place. Dr. Lee relates also a case which
occurred in the practice of a country surgeon,
in which the lower end of the sacrum curved
much forward and was ankylosed to the upper
coccygeal bones, the last only being moveable.
In* certain cases the contraction of this
diameter is brought about by the tilling forward
of the lower end of the sacrum, with an almost
horizontal direction of the lower part of the
sacral curve. I have met with two or three
pelves in which this condition is present,
coexistent with, and evidently caused by, a
curvature of the lower dorsal region of the
spinal column backwards. By such a curvature,
the line of gravity of the trunk is displaced back-
wards, passing through the sacrum consider-
ably behind its base, and making traction upon
it in that direction. The promontory of the
sacrum is by this means dragged backwards
and upwards, and the conjugate diameter of
the brim increased, so as to be equal to, or
greater than, the transverse. The shape of
the brim is thus rendered oblong or oval in
the opposite direction to, and contrasting
with, the ovate deformity presently to be
described. The axis of the superior plane is
rendered more horizontal than normal, by the
increase of the pelvi-vertebral angle, thecotylo-
sacral arch more open in its curve, and the
acetabula in some measure approximated. The
cavity of the pelvis is narrowed antero-pos-
teriorly by the gradual advance downwards
of the posterior wall, and the vertical curvature
* Neue Zeitschrift fur Geburtskunde, t. iv. 1836.
N 4
184
PELVIS.
of the sacrum is more open than usual. Thus
is constituted another variety of funnel-shaped
pelvis, caused mainly by the gradually nar-
rowing of antero-posterior diameters, instead
of the lateral, as in the masculine pelvis be-
fore described.
In the King's College Museum are the pelvis
and spine of a female, well exemplifying this
deformity (see fig. 1 16.). The spine is affected
by a rickety curve, the greatest extent of
which is about the 6th, 7th and 8th dorsal
Fig. 116.
Oblong pelvic deformity. (From a preparation in the
Museum of King's College.)
vertebrae (a), directed backwards to a great
extent, and somewhat to the left side, with a
compensatory curve to the right, at the junc-
tion of the lumbar with the dorsal vertebrae
(b). The lower lumbar vertebrae and sacral
promontory are twisted considerably towards
the left side, and dragged backwards, the sacral
promontory being also considerably raised up-
wards (c). The pelvis is of exceedingly large
general capacity, and otherwise well formed,
showing evidently, by the preponderance of
end of the sacrum ; while the upper dorsal
vertebrae incline forward, so as to bring the
1st dorsal over the centre of the pelvic circle.
There is, in this case, no lateral deviation of the
spinal column. The tibia? and fibulae have an
inward curve, indicating the existence of a
softened rickety state of the bones at an
early period of life.
In the Hunterian collection of pathological
specimens is a young adult pelvis, numbered
3420, presenting the same kind of deformity,
accompanying the same kind of backward
angular curvature and ankylosis of the bodies
of the vertebrae at the same place viz. the
junction of the last dorsal and 1st lumbar.
The 1st dorsal vertebra, in this skeleton,
likewise occupies a position above the centre
of the pelvic opening. The upper end of the
sacrum is dragged backwards by the inclined
lumbar vertebrae so as to increase the con-
jugate diameter of the brim to 4^ inches.
The lower end of the sacrum is tilted forward
so as to bring the tip of the coccyx to within
a short distance of the ischial spines. The
cotylo-sacral arch is stretched out, and the
transverse diameter of the brim reduced to
4 inches only. The acetabula are directed
more downwards than usual, and the right
iliac wing is pressed outwards by the 9th and
10th ribs, which rest on it, and the venter
completely flattened out.
I find that Rokitansky has met with in-
stances of this oblong deformity of the pelvis,
coexisting with backward angularity of the
spine.
In cases of backward angular curvature
low down the spine, especially where there
is no lateral deviation, there will be a
tendency to production of this form of pelvis,
especially if the bones be somewhat softened,
as they usually are in these cases; and al-
though such cases of pelvic distortion are,
as far as I have seen, more common in the
male, yet the same cause occasionally produces
this effect upon the female pelvis, and may
produce obstruction during parturition, not
only by the contraction of the antero-posterior
diameter at the outlet, but even at the brim,
by the diminution of its transverse diameter.
An acute angle in the lower part of the
the conjugate diameter and appearance of sacral curve may also produce this contraction
of the inferior pelvic outlet. When this exists
singly, the elevation of the coccyx is more
considerable than usual, and the axis of the in-
ferior plane directed more backwards. This
bending upwards of the apex of the sacrum is,
however, most usually seen in connection with
more general pelvic deformity, and is some-
times accompanied by ankylosis of the sacro-
coccygeal joint.
In a case recorded by Mr. Bell, the antero-
posterior diameter of the inferior outlet was
contracted to half-an-inch only, and in one
of Naegele's, it was even less than this, in
both entirely precluding delivery. In so great
a contraction, the sacral bend must have been
unusually great, or the lower end of that
bone tilted forward in the manner just de-
scribed.
the sacrum, the effect of the deformed spine
upon it. The conjugate diameter of the brim
measures as much as 5 and a half inches ;
the transverse 5|- inches. At the outlet, the
distance between the tuberosities is only 3-|
inches, and the sub-pubic angle 75 ; but,
from an unfortunate deficiency of the lower
end of the sacrum, the antero-posterior
diameter cannot be measured.
In the same Museum there is a young male
adult skeleton in which this form of pelvis
is also well shown. It, also, is coexistent
with, and dependant on, a backward cur-
vature and shortening of the spine, and ex-
tensive ankylosis of the vertebrae in the
dorsal and lumbar regions. The lumbar ver-
tebrae are inclined much backward, so as to
drag in the same direction upon the upper
PELVIS.
185
Distortions affecting the whole pelvis. In
these cases the pubic bones are always more or
less extensively implicated in the distortion, and
entering, as they do, into the formation of
both brim, cavity, and outlet, all these parts
of the pelvis are contracted or mispropor-
tioned. At the brim, however, the obstruc-
tion usually takes place, while the operations
necessary to procure delivery through the
natural passages are rendered more difficult
by the distortion of the cavity and inferior
opening.
General distortions of the pelvis are com-
monly divided into three kinds, named, from
the shape of the brim, the ovate or elliptical,
the cordiform or angular, and the obliquely
ovate.
The ovate, elliptical, or reniform pelvis.
In this distortion the sacrum is placed almost
horizontally, so that the sacral promontory pro-
jects forward to a great degree, generally at the
same time deviating from the median line, and
considerably sunk in a direction forwards
and downwards, so that the lowest lumbar
vertebra forms the most projecting point.
The lateral sacral curve is diminished, flat-
tened out, and often bent backwards on each
side the promontory. The vertical curvature
is generally diminished and flattened in some
degree, and directed more downwards by the
more horizontal position of the bone; but
occasionally there is an acute bend forwards
at the lower part. The coccyx is generally
bent acutely forwards.
The ilia and ischia on each side are often
removed to a greater lateral distance than
normal. The iliac wings are flattened and
directed more forward ; and the cotylo-
sacral arch is more sharply curved, and often
shorter and thicker than normal. The planes
of the ischia diverge instead of slightly con-
verging downward ; the spines and tuberosities
being likewise divergent, and the latter di-
rected more outwards and backwards. The
superior rami of the pubes are generally flat-
tened out, having little anterior projection ;
while the inferior rami are widely divergent,
affording a wider and shallower expansion of
the sub-pubic arch. In some cases, however,
the sub-pubic arch is little altered
In some instances the symphysis of the
pubis presents the appearance of being in-
dented or pushed backwards, giving an out-
line to the brim of an hour-glass shape.
The diameter principally diminished is the
conjugate of the brim, and often one or other
of the oblique diameters. In one variety the
transverse diameter of the brim is also con-
tracted. The transverse diameter is, however,
sometimes undiminished, or even increased.
The transverse diameter of the inferior outlet is
generally most considerably increased ; but the
antero-posterior diameter is most usually con-
tracted by the bend in the sacrum. In many
instances, however, it is considerably enlarged.
The depth of the true pelvis is generally dimi-
nished, and its capacity lessened.
The sacro-vertcbral angle is generally much
diminished, from the backward horizontal di-
rection of the upper end of the sacrum.
The inclination of the superior plane is some-
times increased so much as to be vertical ; the
axis of the brim being generally directed more
forward than in the " standard" and that of
the inferior outlet more backward. Some-
times, however, they are very little altered.
The structure of the bones is light, slender,
and fragile, indicating the origin of the dis-
tortion in rickety softening.
Examples of this kind of pelvis are nu-
merous. One of the most well-known is that
of Elizabeth Sherwood, who was delivered by
Dr. Osborne by means of the crochet. The
measurements of this pelvis are given as fol-
lows : From the most prominent point of the
lumbar vertebra to the upper border of the
pubic symphysis, li inch. From the same
point on the left side to the left pectineal
eminence, If inches. The same measurement
on the right side, 1| inches. From the sacral
promontory to the pubic symphysis, 1 inch.
Transverse diameter of brim, 5 inches. Left
oblique ditto, 4 inches. Right oblique, 4
inches. Antero-posterior of cavity, 2\ inches.
Transverse ditto, 5 inches. Antero-posterior
of outlet, 2% inches. Transverse, 4 inches.
Sub-pubic angle, 100.
The measurements of a very extreme case
of this kind of distortion are recorded by Dr.
Ramsbotham (see^/%. 117.) as follows:
Fig. 117.
Ovate pelvis. (After Ramsbotham.}
Conjugate or sacro-pubic diameter of brim,
| of an inch only. From right side of sacral
promontory to right pubis, \\ inch. The
same measurement on the left side, If inch.
Antero-posterior diameter of outlet, 2 inches.
Transverse diameter, 4 inches. The shape
of the brim in this pelvis is hour-glass, the
pubic symphysis being pushed back. Such a
pelvis, in the opinion of the above-named
writer, would necessitate the abdominal
section.
In a less extreme case, given by the same
writer, the sacral promontory and lumbar
curve bend much more considerably towards
the left side. At the brim, the conjugate dia-
meter is 1 inch; the right sacro-pubic, 2
186
PELVIS.
inches; the left, f of an inch only. The
transverse diameter, measured in the lateral
curve of the brim, 6^ inches. At the inferior
outlet, the antero-posterior, 4 inches ; the
transverse, 5. In the figure of this pelvis
given by the author, the long axis of the
sacrum is represented as placed obliquely
across the median line, its apex inclining to
the right side; while the tuberosity of the
right ischium is widely divergent, principally
causing the increase of the transverse dia-
meter of the outlet. The left ischial tube-
rosity and acetabulum are brought more
under the line of gravity. The left superior
pubic ram us is thus pushed nearer to the
promontory than the right, causing a slight
twist in the pubic symphysis. In this pelvis
the author considers that delivery might be
effected " per vias naturales," by craniotomy.
In one of Dr. Hull's cases, that of Ann
Lee, affected with this deformity, the con-
jugate diameter was reduced to 1-| inch,
and the sacro-cotyloid on each side equal,
and measuring l^g- inch. The transverse
diameter, in its widest part, amounted to 4^
inches only. There was little flattening of
the pubes, the contraction being produced
chiefly by the projection of the sacrum, the
chief bend being near the sacro-iliac joints.
The distance between the antero-superior
iliac spines was only 8^ inches, but the dimen-
sions of the cavity and inferior outlet were not
materially diminished.
In Mr. Thomson's case of Caesarian section,
the pelvis was affected with this deformity.
The normal lumbar curvature was so much
increased, together with the pelvic inclination,
that the sacrum was placed quite horizontal,
and the superior plane directly vertical, and
its axis consequently parallel with the hori-
zon; but with little or no lateral deviation
of the sacral promontory. The legs were
crooked, and the acetabula faced directly
forwards. The conjugate diameter of the
brim was diminished to $ of an inch ; the
transverse was about 5 inches, and the inter-
sciatic apparently about 4.*
Dr. Robert Lee gives the dimensions of a
case of ovate deformity in which the patient,
after being delivered by craniotomy at an
early period of pregnancy in the first labour,
died in the second from rupture of the uterus.
The conjugate diameter of the brim was 2
inches 1 line; the transverse, 5f inches. At
the outlet the distance between the sciatic
tuberosities was 4 inches ; between the tip
of the coccyx and lower border of the pubic
symphysis, Si inches. This obstetrician con-
siders that if, in this case, premature labour
had been induced at or before the fifth, in-
stead of the seventh month, the patient might
have been saved.f
It has been said that in pelves presenting
the ovate deformity from rickets, the contrac-
tions of the diameters of the brim are generally
* Med. Observations and Inquiry, vol. iv., with
plates.
f Lectures in Med. Gazette, 1843, p. 181.
accompanied by the enlargement of those of
the outlet, and the numerous examples of
enlarged transverse diameters of the outlet,
in particular, are adduced.
In an ovately deformed pel vis in the Museum
of King's College, however, in which the con-
jugate diameter of the brim is 2 inches, and the
transverse also contracted to 4f inches ; at the
outlet the inter-sciatic diameter is contracted
to as little as 3| inches, and with it the sub-
pubic angle is diminished also, while the
antero-posterior is increased to 4 inches.
This pelvis is remarkable for the great flat-
tening of the sacrum, the anterior surface of
which lies almost in a straight line, in which
direction the coccyx also is nearly placed.
The antero-posterior diameter of the cavity
is thus reduced to 3 inches. The distance
between the ischiai spines is, however, 4>
inches. The sacral promontory projects more
forwards than downwards, and the lumbar
curve is inclined to the left side. In this
pelvis the brim is contracted considerably in
all its diameters, and this contraction is
evidently produced by the crushing down-
wards of the sides of the cotylo-sacral arch.
The length of the cotylo-sacral rib on the
right side, taken from opposite the ilio-pec-
tineal eminence to the sacro-iliac angle along
the curve, amounts to only ]i inch, while the
direct measurement is reduced to 1 inch.
The rib of bone is at the same time much
increased in thickness, presenting an almost
cubical mass between the cotyloid and sacro-
iliac articulations. On the left side, the direct
measurement is a little more.
In the table of measurements of diseased
pelves given by Dr. Murphy, the transverse
diameter of the brim in the five ovate pelves
amounts to 5 inches only in two cases, and
in a third, it is diminished to 4f inches. In
many of these cases we may conclude that
the cotylo-sacral rib was shortened as well as
bent backward. The transverse diameter of
the inferior opening is not enlarged in all the
above-mentioned cases. In one it amounted
only to 3f, and the sub-pubic angle (mainly
depending on this diameter) is only 70.
The antero-posterior diameter is, in* three
cases, increased to from 4 to 4| inches, while
in the remaining two cases it is diminished
to 2% and 2-J. These latter measurements,
doubtless, depend in great measure upon the
position of the coccyx, or, as in the case
above given from the Museum of King's Col-
lege, upon the flatness of the sacrum, or in
its bend. They show, however, that the en-
largement of the inferior diameters in not uni-
versally characteristic of the general ovate
deformity. We may also conclude that the
general contraction of the diameters of the
brim, which is often found in these pelves, is
produced mainly by the shortening of the
col^lo-sacral rib of the ilium in the line of
pressure, without any aversion of the lower
part of the innominate bones.
A singular pelvic deformity, related in
some degree to this class, is represented in
Moreau's plates, in which, by an anterior
PELVIS.
187
bend at the lower lumbar vertebras, the
sacrum is placet! horizontally backward, and
the sacro-vertebral angle diminished to rather
less than a right angle. The effect of this is
to increase the obliquity of the innominate
bones, and the distance from the sacrum to
the pubis, to approximate the pubis and
coccyx, and to widen the transverse diameters.
With the exception of the last-named pecu-
liarities, this pelvis presents the condition and
appearance of that of a quadruped, in being
placed horizontally; the trunk, however,
being kept in the vertical position by the re-
markable sacro-vertebral bend.
The cordiform or angular pelvis. This
distortion presents wide differences to the
kind just described.
The sacral promontory, though in some
measure projecting forwards, yet is more
clecidedlv sunk down below its proper level
into the cavity of the pelvis, with an in-
clination to one side of the median line, in
most cases to the left. The lateral masses
of the sacrum are likewise bent back, alter-
ing the outline of the lateral sacral cur-
vature. The vertical curvature of the sacrum
is also increased to a great degree ; the hollow
of the sacrum, in many cases, being almost
bent double. The coccyx is generally placed
horizontally.
The ilia and ischia on each side are
pushed together upwards and towards the
sacrum, so that the acetabula are thereby
approximated and placed nearer to the
sacral promontory. The cotylo-sacral arch