particularly of the medullary web, or external injury; a termination of
inflammatory action in bone corresponding to sphacelation in the softer
tissues. It has been observed, that the bones are not extensively
supplied with bloodvessels, and that their natural powers are inferior
to those of the softer parts; and from this circumstance the frequency
of necrosis can be readily accounted for. The short bones and the
heads of the long bones, are more vascular than the flattened bones
and the shafts of the long ones. Hence necrosis most frequently occurs
in the latter. Necrosis, fortunately, seldom occurs in the heads of
the long bones, or penetrates the separation betwixt the cancelli of
the shaft and the epiphysis. Bits of dead bone in the articular ends,
however, very often lead to disease in the joint. There are in my
private collection a few specimens of necrosis, in which matter found
its way into the neighbouring joint, leading to disease of the tissues
composing it, and rendering amputation necessary for the preservation
of the patient’s existence. External injury may produce this disease
by causing a violent increase of action, or it may be so severe as at
once to deprive part of the bone of its vitality. Destruction of the
periosteum, and of the vessels which enter the surface of the bone,
frequently gives rise to superficial necrosis or exfoliation. Such a
result, however, does not always follow; for we not unfrequently find,
when the periosteum has been forcibly torn off, to a considerable
extent, by external injury, that the part still retains its vitality.
When, however, the bone has been at the same time contused, it is
extremely probable that external necrosis may occur. Again, when the
periosteum has been removed in the most careful manner possible,
exfoliation occasionally takes place. If the exposed bone remain of a
brownish hue, it will generally retain its vigour; if, on the other
hand, the colour is white, it will most probably be cast off. Necrosis
may come on at various periods of life, but is most commonly met with
in young subjects, in whom the inflammatory action is allowed to
make progress before it is noticed or attended to. It may affect the
external or the internal part of a bone, or nearly its whole thickness.
The whole of a bone seldom or ever dies in consequence of increased
action, and it is not often that the entire thickness of any part of
it is found to be necrosed. If the entire thickness dies to a great
extent, there is no reproduction; the epiphyses approximate, and the
limb, if there is only a single bone, must be lost. A large portion
of a bone, or numerous small irregular portions, may die; but still a
part of the original shaft remains, and by its vessels reproduction is
accomplished. The articulating extremity is very rarely destroyed by
this disease. Many writers have talked of death of a bone throughout
its whole extent, and, in fact, the term necrosis was originally
adopted on this supposition.
[Illustration]
[Illustration]
The progress of necrosis is, as has been said, similar to that of
sphacelation. The affected bone gradually changes its colour, and
loses its sensibility; a line of demarcation is formed, and ultimately
the dead portion is completely detached from the living. Previous
to its separation, the surrounding parts, the portions of bone
which are not doomed to perish, have commenced forming new osseous
matter, which is secreted in nodules, and from continued deposition
soon becomes consolidated. The commencement of the process is well
seen in the following sketches from specimens in my collection. The
disease, as represented in the two first cuts, was of the most acute
kind, and a great part of the shaft of the tibia had perished. This
is seen at various points through the sort of cortical deposit of
new bone. The new bone, in its turn, secretes a texture similar to
itself, whereby the deposit becomes more and more extended, and not
unfrequently affords an almost complete encasement to the dead portion,
or sequestrum, as represented in the cut on the right-hand side of the
page. In general bone dies irregularly, so that the sequestrum presents
an uneven surface, and its margins are rough and serrated by numerous
sharp projections, as seen in the one taken from the tibia, and
represented here. From the appearance of the dead bone, it was imagined
that after its separation, portions of it were removed by absorption;
and this opinion was strengthened by the thin exfoliations of the
external lamina being found perforated at several points by minute
apertures,—worm-eaten, as it was called. These cases of death of inner
or medullary shell are irregularly separated, like any other slough;
the remaining living outer shell is enlarged by inflammatory action
and deposit. But a dead portion of bone, detached from the surrounding
parts, is in every respect an extraneous body, and is not, and cannot
be, acted on by the absorbents, any more than a piece of metal, wood,
or stone. Some have gone so far as to affirm that portions of foreign
bodies, ligatures, &c., are absorbed; but this opinion is altogether
too absurd to require any contradiction; the knots of ligatures, like
portions of glass, or other foreign substance, become surrounded with
a dense cyst, and often remain in the body for a long time; so do
portions of dead bone separated by the process here described. A series
of experiments were made by Mr. Gulliver, in order to put this question
at rest, many of which I witnessed and assisted at, and several I also
repeated. Setons of bone were inserted and worn for a long time; thin
plates of bone were confined on suppurating surfaces; pieces of bone
were inserted in the medullary canal of various animals, and kept there
for months, and in one instance for more than a year. These foreign
bodies were weighed with the greatest care and accuracy before and
after they were so exposed to the absorbents, and were found unaltered
in any respect. A paper, detailing these experiments, is published in
the _Medico-Chir. Transactions_.
The separation of the dead part from the living is accomplished with
greater or less ease, according to the bone which is affected, the
state of the constitution, and the general health; in the bones of the
superior extremity, this, as well as every other action, proceeds more
rapidly than in those of the inferior. It occurs in consequence of
absorption of the living part of the bone, which is in close proximity
to the dead. The sequestrum, if large, is not pushed off, as some
have supposed, by granulations, deposited on the living margin of the
bone. A small portion of the inner shell, when completely detached,
may sometimes be observed to be extruded from a cloaca by granulations
from the living bone. During its progress, matter forms, makes its way
to the surface, and is discharged through minute, and often numerous
apertures, which afterwards become fistulous. The soft parts are
thickened and indurated, and the integuments are red, and sometimes of
a livid colour.
Formation of matter upon the bone is occasionally the cause of
necrosis, the periosteum being destroyed or separated from its
connections by the pressure or insinuation of the pus. I have seen
several instances in which it followed neglected erysipelas of the
lower extremity.
The matter is in general thick and laudable; at first it is secreted
profusely, but afterwards in smaller quantity. The external openings,
or papillæ, through which it is discharged, are found to lead to
cloacæ, or apertures in the new and living bone, which encase the dead,
and through these the dead portions can be discovered by the probe;
and it will thus be ascertained whether the sequestrum is fixed or
detached: when loose, it can sometimes be moved upward and downward in
the cavity. When the shaft of a bone is much affected, the whole limb
is enlarged, by the inflammation having extended to a considerable
distance above and below the portion about to become necrosed. The
unshapely appearance of the limb continues until the sequestra are
discharged; for by their presence incited action is still continued,
and subsides only after their removal. Some time before any portion of
bone has become dead, or begun to be separated, great effusion of new
bone has, in general, occurred; thus a preparation has been made for
the strengthening of the limb, which, after a considerable portion of
the bone has been detached, would otherwise be incapable of supporting
the weight of the body. The unnatural bulk of the limb is afterwards
much diminished, for the new bone gradually becomes consolidated, and
smooth on the surface by the action of the absorbents. Nature seems to
construct her substitute after the model of the original, and in some
instances but very little change can afterwards be observed in the limb.
In external necrosis, or death of the outer lamella, reparation is
chiefly made by the subjacent parts; and this species of necrosis
occurs most frequently in the flat bones. In necrosis involving a
greater thickness of the bone, the new matter is also furnished by
the subjacent parts, which, however, are materially assisted in the
process by the living bone, which forms the margins of the void caused
by the absorbent process for the detachment of the dead portion. The
bony matter is deposited with great activity, and frequently columns of
the new deposit cross over the sequestrum, binding it firmly down, and
rendering it almost immovable, although it may be completely detached
from the living parts.
It has already been stated, that those vessels which ramify within the
substance of the periosteum have no share in the reproduction of bone,
but plastic matter is effused by the ramifications extending from the
membrane to the bone: this effusion becomes organised, and greatly
assists in forming the substitute.
It has been formerly remarked, that a limited, and, on after
examination, an apparently trifling necrosis of the cancellated
structure, may produce the most violent local symptoms; the painful
feelings, the discharge, and the thickening of the bone, continue, as
long as the cancellated sequestrum remains; severe symptomatic fever
is induced, endangering the life of the patient, and often rendering
removal of the limb absolutely necessary.
Occasionally abscesses form at a considerable distance from the
necrosed part, and terminate in sinuses, which communicate with
the diseased bone, and are consequently long and tortuous, so that
examination by the probe is rendered difficult. When necrosis is
extensive, there is a risk of fracture occurring, if motion of the limb
be permitted before a sufficient quantity of matter has been effused,
before nature has had sufficient time for the consolidation of her
substitute, and consequently before the new bone has come to resemble
the old in thickness and cohesion.
Violent inflammatory fever attends the incited action of the vessels
of the bone and periosteum which precedes necrosis. But after the
abscesses have given way the painful symptoms subside, and the health
seldom suffers to any great extent, the system becoming gradually
accustomed, as it were, to the new condition of the parts. Hectic
supervenes only when the disease is very extensive, and joints become
involved. Frequently fresh collections of matter form as each piece of
bone approaches the surface. When the effusion of new bone has extended
to the neighbourhood of a joint, its motion may be very much impeded,
and, from the limb being kept in a state of rest for the cure of the
necrosis, anchylosis may even occur.
_Treatment._—The means of preventing inflammatory action from
running high and ending in death of bone have been already alluded
to—abstraction of blood, rest, purgatives, and antimonials. When
necrosis has occurred, no interference with the bone is allowable,
unless the sequestrum is quite loose, or unless the patient’s health
is suffering severely under the discharge and irritation. When the
sequestrum can be readily moved about, or when, projecting through the
external opening, it can be laid hold of by the fingers or forceps,
attempts must be made to remove it. The surgeon ought not, however,
to allow it to approach the surface, and project externally, for the
natural discharge of the sequestrum is a much more tedious process
than the removal of it by art, and by the irritation produced during
its spontaneous ejection the inflammatory action is continued, and may
prove alarming. Long before it has appeared externally, it must have
been completely separated from the living parts, so as to admit of
ready extraction by the proper means. When it has been ascertained that
the sequestrum is separated, it ought to be laid hold of by forceps,
and moved freely upward and downward, so that any slight attachments
by which it is connected to the neighbouring parts may be destroyed,
whether these be minute filaments which still in some degree retain
their vitality, or small portions of newly deposited bone, which are
so situated as to prevent the free movement of the sequestrum. In
general, no impediment of this nature exists, and the dead bone is
easily removed. Before extraction can be accomplished, it is generally
necessary to enlarge freely the external opening, in all cases where
the dead portion of bone is of considerable size. If, on thus exposing
the parts, the sequestrum be found detached, but still firmly bound
down by the substitute bone, deposited over it either in one continuous
sheet, or in irregular columns, this must be divided by a trephine, a
small saw, or cutting pliers, before the sequestrum can be extracted.
When a dead portion of bone, of considerable length, is exposed at its
centre, whilst its extremities are entangled by the old or substitute
bone, the division of the exposed part of sequestrum, by means of the
cutting pliers, will often be sufficient for its removal, the cut ends
being seized by the forceps, and one half removed after the other;
thus the perforation or removal of any portion of the substitute will
be rendered unnecessary. The instruments, and especially those for
extraction, ought to be very powerful, and suited to the purpose; for
in the employment of inefficient means there is much folly and cruelty.
Incisions into a necrosed limb are attended with profuse hemorrhage
from the enlarged and excited vessels; and in some cases it is with
difficulty arrested, in consequence of retraction of the cut ends of
the vessels not taking place within the condensed and indurated parts.
Pressure, and an elevated position of the part, will generally be
found to answer. When necrosis has been extensive, the limb must be
carefully supported by the application of splints and bandage, till
the process of reparation be completed, in order to prevent fracture
of the recently formed substitute. This proceeding is seldom, however,
necessary.
The treatment may be summed up in a very few words. Prevent the
necrosis, if possible; open abscesses whenever they appear; encourage
the patient to move the neighbouring joints; support the strength;
remove sequestra when loose, but do not interfere till they are
ascertained to be so; give the limb proper support and rest, when a
large sequestrum is formed. When fracture has taken place, when the
health has been undermined, or when neighbouring joints have become
diseased, amputate, in order to save the life, if it be impossible to
save the limb.
[Illustration]
It is almost superfluous to remark, that leeching and blistering are
worse than useless after necrosis has occurred, however useful they may
be in preventing it; and that the adoption of measures to promote the
dissolution and absorption of the sequestra are glaringly absurd.
Necrosis, after amputation, was formerly frequent; but in the present
improved state of this operation it is so rare as scarcely to demand
separate consideration.
[Illustration]
Such specimens as here depicted are common enough in the collections
of those who have practised the old round-about operation; in fact,
it is only by this painful and tedious interference of nature that a
tolerable stump is formed in many of these cases. Death of a small
portion will sometimes, though very rarely, follow even a very well
performed amputation, if through any mischance the recovery is
slow, and wasting discharge takes place with emaciation. It happens
sometimes, as when secondary hemorrhage (that is to say, bleeding after
the fourth day) has taken place, that the flaps are separated by the
coagula, and it may be impossible to bring the parts together and give
them due support; then the muscles, wasted and shrunk, may leave the
bone a little, but the exfoliation is but very trifling.
The inner shell of bone, as may be seen in the above sketch, perishes
more extensively than the outer; and this arises probably from
inflammation of the medullary membrane, in consequence of exposure, or,
perhaps, from its being sometimes injured by the operator or assistants
seizing the bone rudely to steady the stump, in order to facilitate the
ligature of the vessels. In experiments on animals, the disturbance
and injury of the medullary membrane is followed by internal necrosis,
thickening of the outer living shell, and effusion betwixt the
periosteum and bone. New bone is also furnished from the medullary
canal, as is also shown in the sketch.
FRAGILITAS OSSIUM
Occurs chiefly in old people, whose bones contain an undue proportion
of earthy matter, are endowed with little vascularity, and filled with
an oleaginous fluid. They contain an undue quantity of phosphate of
lime compared to the gelatin; and the liability to fracture is further
increased by the interstitial absorption of the outer shell. They are
in an atrophied state, and this is often in part attributable to disuse
of the limbs. This state of the osseous system very often follows upon
an attack of rheumatic fever, and is met with in patients who have
laboured under cancerous affections.
The bones, when in this condition, often break from the slightest force
applied; as from the action of the muscles when the patient turns
himself in bed, whilst walking across the room, or when endeavouring
to attain the erect posture when seated on a chair. After fracture
the process of reunion is extremely slow, and it does not take place
at all in patients very old and of worn-out constitution. With a view
to prevent the occurrence of fracture when the bones are in this
condition, for it is impossible by any treatment to prevent the change
in the texture of the bones, the only rational indications seem to be
to keep the patient on a generous diet, and to prohibit him from making
any great muscular exertion—to avoid, in fact, all circumstances likely
to produce a sudden action of any particular set of muscles.
OF MOLLITIES OSSIUM, RACHITIS, ETC.
These affections differ only in this, that in the latter the earthy
matter is not deposited originally, whilst in the former it is absorbed
after having been deposited; in both the result is the same. The latter
is peculiar to the very young, the former to those of an advanced
age.[11]
Rickets and mollities ossium seem to differ also in this. In the latter
there is seldom, if ever, any reparative action. The diseased process
of deposit continues in the bone, the softening increases, and the
patient ultimately perishes. Whereas, in rickets, the softened and
yielding state of the bones is only temporary: after a time earthy
matter is deposited in due quantity, and the bones become compact,
firm, and solid, capable of supporting the weight of the body, though
necessarily permanently bent and deformed, if proper means have not
been employed during the softened condition. The thickness of the
rickety bone, as Mr. Stanley has shown, takes place on the concavity,
which is the situation where the greatest strength may be added with
the least expense of new matter. In the same way the reparation
of fractures not accurately adjusted goes on most actively in the
concavity formed by their displacement.
[Illustration]
Softening of the bones is met with at all ages, and in different
degrees. It seems sometimes to be congenital, and combined with
hydrocephalus. It often follows dentition, measles, hooping-cough, or
other infantile diseases inducing debility. In females it seems to be
produced, or at least often accompanied, by the debilitating effects
of leucorrhœa, miscarriages, and floodings. Loss of blood, in any way,
predisposes to it. Mercury, given in immoderate quantities, produces
a softening of the bones; and, in some most remarkable instances on
record, the free use of common salt was the only cause assigned. When
the disease affects children, all the bones generally suffer, those of
the extremities as well as those of the trunk; the limbs become bent
in an extraordinary manner, and the heads of the bones are swollen,
and appear to be much more so in consequence of the wasted and flabby
state of the muscles. The child walks with difficulty, and in many
cases the legs are utterly incapable of supporting the weight of the
body, so that he cannot remain in the erect position. The chest and
pelvis become deformed, breathing is oppressed, the digestive organs
are deranged, and the belly is tumid. The bones of the limbs become
flattened as well as bent, and in their concavities, as remarked in the
preceding cut, new bone is effused, in order that the column of support
may be thereby strengthened. The new deposit is of extremely dense
consistence, and is effused in greater or less quantity, according to
the degree of curvature.
The bones of rickety subjects are soft, cellular, and of a brown
colour, contain a dark fluid, and are very deficient in earthy matter.
As a simple proof of the latter circumstance, it may be mentioned
that distortions of the pelvis can be, and often are, accurately
imitated by soaking the bones for some time in acid, whereby the earthy
matter is extracted. In many instances this component of the bones is
almost entirely removed, and soft matter deposited instead; they then
consist merely of an extremely thin external osseous shell, covered by
thickened periosteum, and containing a pulpy substance resembling fatty
matter. During the progress of the disease, the urine deposits, often
in great quantity, a white sediment, which, on analysis, is found to
be the phosphate of lime. In rickets the head is generally enlarged to
a greater or less degree, and the bones of the cranium are thickened
and spongy; not unfrequently the intellectual faculties remain acute.
In adolescents and adults the limbs seldom become affected; the
bones composing the spinal column are the seat of the disease, and,
along with the distortion of the spine, the position of the ribs is
necessarily altered. Certain rare cases have occurred, in which all
the bones of the adult were softened to a very great degree. In one
remarkable instance, the patient complained of an annoying sense of
tightness in the limb most affected, and, on examination, the softened
bone was found greatly depressed at that point, as if a strong ligature
had been drawn tightly round it. Mr. Howship, who attended the patient,
was so kind as to present me some years ago with a portion of the
altered femur, which consists of a fatty-looking substance, and appears
to contain little or no earthy matter.[13]
Though incurvation of the spine occurs in boys, and even in adults,
still it is most frequently met with in young females; and in them it
is often induced by their having assumed a bad habit by sitting long in
one constrained and awkward posture, as in writing or drawing, without,
perhaps, the bones being unnaturally soft in the first instance.
It often follows affections of the lower limbs, as of the knee or
hip-joint; and is also caused by shortening of a limb, which has been
negligently or ineffectually treated after fracture during childhood,
or by the patient being allowed to continue a custom of standing
awkwardly on one leg. In a very remarkable specimen in my possession,
the curvature seems to have resulted from the tremendous enlargement
and consequent weight of the head. The whole skeleton (head, thorax,
pelvis, and extremities) is deformed, flattened, and twisted. This may
have arisen more readily in consequence of the atrophy of the bones,
and retardation of their growth, produced by the long confinement
to bed. The number of ossa triquetra in the lambdoidal suture was
unusually great. The patient attained the age of twenty-five. The
affection commenced from birth.
[Illustration]
At first, during slight curvature from such causes, the spine can be
brought into its original straight position by the voluntary action of
its muscles. After some time, however, the curve cannot be remedied
by any effort; interstitial absorption of the bodies of the vertebræ
towards the concavity of the curve occurs; they become changed in
form, and accommodated to their altered position, as shown in the
accompanying sketch; the muscles also accommodate themselves to the
new position, as do also the various ligaments connected with the
spinal column. When the curvature is seated in the dorsal vertebræ it
is generally to the right side; this shoulder is raised, and the chest
is protruded, whilst the opposite side is depressed and flattened. The
clothes hang loose, or fall off on the left side—the patient rests
the weight of his body chiefly on the left leg—on stooping the right
scapula projects, and, on examination, is found to be nearer to the
spinous processes of the vertebræ than the left. The left cavity of
the chest is diminished, and the ribs press upon the heart and lungs,
causing difficulty of breathing. To preserve the balance of the body,
a curvature occurs below the former, and in the opposite direction;
and not unfrequently there is a third incurvation situated above the
primary one.