DISEASES OF BONE
Anatomy and physiology--Regeneration of bone--Transplantation of bone.
DISEASES OF BONE--Definition of terms--Pyogenic diseases:
_Acute osteomyelitis and periostitis_; _Chronic and relapsing
osteomyelitis_; _Abscess of bone_--Tuberculous disease--Syphilitic
disease--Hydatids; Rickets; Osteomalacia--Ostitis deformans of
Paget--Osteomyelitis fibrosa--Affections of bones in diseases of
the nervous system--Fragilitas ossium--Tumours and cysts of bone.
#Surgical Anatomy.#--During the period of growth, a long bone such as
the tibia consists of a shaft or _diaphysis_, and two extremities or
_epiphyses_. So long as growth continues there intervenes between the
shaft and each of the epiphyses a disc of actively growing
cartilage--_the epiphysial cartilage_; and at the junction of this
cartilage with the shaft is a zone of young, vascular, spongy bone known
as the _metaphysis_ or _epiphysial junction_. The shaft is a cylinder of
compact bone enclosing the medullary canal, which is filled with yellow
marrow. The extremities, which include the ossifying junctions, consist
of spongy bone, the spaces of which are filled with red marrow. The
articular aspect of the epiphysis is invested with a thick layer of
hyaline cartilage, known as the _articular cartilage_, which would
appear to be mainly nourished from the synovia.
The external investment--the _periosteum_--is thick and vascular during
the period of growth, but becomes thin and less vascular when the
skeleton has attained maturity. Except where muscles are attached it is
easily separated from the bone; at the extremities it is intimately
connected with the epiphysial cartilage and with the epiphysis, and at
the margin of the latter it becomes continuous with the capsule of the
adjacent joint. It consists of two layers, an outer fibrous and an inner
cellular layer; the cells, which are called osteoblasts, are continuous
with those lining the Haversian canals and the medullary cavity.
The arrangement of the _blood vessels_ determines to some extent the
incidence of disease in bone. The nutrient artery, after entering the
medullary canal through a special foramen in the cortex, bifurcates, and
one main division runs towards each of the extremities, and terminates
at the ossifying junction in a series of capillary loops projected
against the epiphysial cartilage. This arrangement favours the lodgment
of any organisms that may be circulating in the blood, and partly
accounts for the frequency with which diseases of bacterial origin
develop in the region of the ossifying junction. The diaphysis is also
nourished by numerous blood vessels from the periosteum, which penetrate
the cortex through the Haversian canals and anastomose with those
derived from the nutrient artery. The epiphyses are nourished by a
separate system of blood vessels, derived from the arteries which supply
the adjacent joint. The veins of the marrow are of large calibre and are
devoid of valves.
The _nerves_ enter the marrow along with the arteries, and, being
derived from the sympathetic system, are probably chiefly concerned with
the innervation of the blood vessels, but they are also capable of
transmitting sensory impulses, as pain is a prominent feature of many
bone affections.
It has long been believed that _the function of the periosteum_ is to
form new bone, but this view has been questioned by Sir William Macewen,
who maintains that its chief function is to limit the formation of new
bone. His experimental observations appear to show that new bone is
exclusively formed by the cellular elements or osteoblasts: these are
found on the surface of the bone, lining the Haversian canals and in the
marrow. We believe that it will avoid confusion in the study of the
diseases of bone if the osteoblasts on the surface of the bone are still
regarded as forming the deeper layer of the periosteum.
The formation of new bone by the osteoblasts may be _defective_ as a
result of physiological conditions, such as old age and disease of a
part, and defective formation is often associated with atrophy, or more
strictly speaking, absorption, of the existing bone, as is well seen in
the edentulous jaw and in the neck of the femur of a person advanced in
years. Defective formation associated with atrophy is also illustrated
in the bones of the lower limbs of persons who are unable to stand or
walk, and in the distal portion of a bone which is the seat of an
ununited fracture. The same combination is seen in an exaggerated degree
in the bones of limbs that are paralysed; in the case of adults, atrophy
of bone predominates; in children and adolescents, defective formation
is the more prominent feature, and the affected bones are attenuated,
smooth on the surface, and abnormally light.
On the other hand, the formation of new bone may be _exaggerated_, the
osteoblasts being excited to abnormal activity by stimuli of different
kinds: for example, the secretion of certain glandular organs, such as
the pituitary and thyreoid; the diluted toxins of certain
micro-organisms, such as the staphylococcus aureus and the spirochæte of
syphilis; a condition of hyperæmia, such as that produced artificially
by the application of a Bier's bandage or that which accompanies a
chronic leg-ulcer.
The new bone is laid down on the surface, in the Haversian canals, or
in the cancellous spaces and medullary canal, or in all three
situations. The new bone on the surface sometimes takes the form of a
diffuse _encrustation_ of porous or spongy bone as in secondary
syphilis, sometimes as a uniform increase in the girth of the
bone--_hyperostosis_, sometimes as a localised heaping up of bone or
_node_, and sometimes in the form of spicules, spoken of as
_osteophytes_. When the new bone is laid down in the Haversian canals,
cancellous spaces and medulla, the bone becomes denser and heavier, and
is said to be _sclerosed_; in extreme instances this may result in
obliteration of the medullary canal. Hyperostosis and sclerosis are
frequently met with in combination, a condition that is well illustrated
in the femur and tibia in tertiary syphilis; if the subject of this
condition is confined to bed for several months before his death, the
sclerosis may be undone, and rarefaction may even proceed beyond the
normal, the bone becoming lighter and richer in fat, although retaining
its abnormal girth.
The _function of the epiphysial cartilage_ is to provide for the growth
of the shaft in length. While all epiphysial cartilages contribute to
this result, certain of them functionate more actively and for a longer
period than others. Those at the knee, for example, contribute more to
the length of limb than do those at the hip or ankle, and they are also
the last to unite. In the upper limb the more active epiphyses are at
the shoulder and wrist, and these also are the last to unite.
The activity of the epiphysial cartilage may be modified as a result of
disease. In rickets, for example, the formation of new bone may take
place unequally, and may go on more rapidly in one half of the disc than
in the other, with the result that the axis of the shaft comes to
deviate from the normal, giving rise to knock-knee or bow-knee. In
bacterial diseases originating in the marrow, if the epiphysial junction
is directly involved in the destructive process, its bone-forming
functions may be retarded or abolished, and the subsequent growth of the
bone be seriously interfered with. On the other hand, if it is not
directly involved but is merely influenced by the proximity of an
infective focus, its bone-forming functions may be stimulated by the
diluted toxins and the growth of the bone in length exaggerated. In
paralysed limbs the growth from the epiphyses is usually little short of
the normal. The result of interference with growth is more injurious in
the lower than in the upper limb, because, from the functional point of
view, it is essential that the lower extremities should be approximately
of equal length. In the forearm or leg, where there are two parallel
bones, if the growth of one is arrested the continued growth of the
other results in a deviation of the hand or foot to one side.
In certain diseases, such as rickets and inherited syphilis, and in
developmental anomalies such as achondroplasia, _dwarfing_ of the
skeleton results from defective growth of bone at the ossifying
junctions. Conversely, excessive growth of bone at the ossifying
junctions results in abnormal height of the skeleton or _giantism_ as a
result, for example, of increased activity of the pituitary in
adolescents, and in eunuchs who have been castrated in childhood or
adolescence; in the latter, union of the epiphyses at the ends of the
long bones is delayed beyond the usual period at which the skeleton
attains maturity.
#Regeneration of Bone.#--When bone has been lost or destroyed as a
result of injury or disease, it is capable of being reproduced, the
extent to which regeneration takes place varying under different
conditions. The chief part in the regeneration of bone is played by the
osteoblasts in the adjacent marrow and in the deeper layer of the
periosteum. The shaft of a long bone may be reproduced after having been
destroyed by disease or removed by operation. The flat bones of the
skull and the bones of the face, which are primarily developed in
membrane, have little capacity of regeneration; hence, when bone has
been lost or removed in these situations, there results a permanent
defect.
Wounds or defects in articular cartilage are repaired by fibrous or
osseous tissue derived from the subjacent cancellous spaces.
_Transplantation of Bone--Bone-grafting._--Clinical experience is
conclusive that a portion of bone which has been completely detached
from its surroundings--for example, a trephine circle, or a flap of bone
detached with the saw, or the loose fragments in a compound
fracture--may become, if replaced in position, firmly and permanently
incorporated with the surrounding bone. Embedded foreign bodies, on the
other hand, such as ivory pegs or decalcified bone, exhibit, on removal
after a sufficient interval, evidence of having been eroded, in the
shape of worm-eaten depressions and perforations, and do not become
united or fused to the surrounding bone. It follows from this that the
implanting of living bone is to be preferred to the implanting of dead
bone or of foreign material. We believe that transplanted living bone
when placed under favourable conditions survives and becomes
incorporated with the bone with which it is in contact, and does not
merely act as a scaffolding. We believe also that the retention of the
periosteum on the graft is not essential, but, by favouring the
establishment of vascular connections, it contributes to the survival of
the graft and the success of the transplantation. Macewen maintains that
bone grafts "take" better if broken up into small fragments; we regard
this as unnecessary. Bone grafts yield better functional results when
they are immovably fixed to the adjacent bone by suture, pegs, or
plates. As in all grafting procedures, asepsis is essential.
Transplanted bone retains its vitality when embedded in the soft parts,
but is gradually absorbed and replaced by fibrous tissue.
DISEASES OF BONE
The morbid processes met with in bone originate in the same way and lead
to the same results as do similar processes in other tissues. The
structural peculiarities of bone, however, and the important changes
which take place in the skeleton during the period of growth, modify
certain of the clinical and pathological features.
_Definition of Terms._--Any diseased process that affects the periosteum
is spoken of as _periostitis_; the term _osteomyelitis_ is employed when
it is located in the marrow. The term _epiphysitis_ has been applied to
an inflammatory process in two distinct situations--namely, the
ossifying nucleus in the epiphysis, and the ossifying junction or
metaphysis between the epiphysial cartilage and the diaphysis. We shall
restrict the term to inflammation in the first of these situations.
Inflammation at the ossifying junction is included under the term
osteomyelitis.
The term _rarefying ostitis_ is applied to any process that is attended
with excessive absorption of the framework of a bone, whereby it becomes
more porous or spongy than it was before, a condition known as
_osteoporosis_.
The term _caries_ is employed to indicate any diseased process
associated with crumbling away of the trabecular framework of a bone. It
may be considered as the equivalent of ulceration or molecular
destruction in the soft parts. The carious process is preceded by the
formation of granulation tissue in the marrow or periosteum, which eats
away and replaces the bone in contact with it. The subsequent
degeneration and death of the granulation tissue under the necrotic
influence of bacterial toxins results in disintegration and crumbling
away of the trabecular framework of the portion of bone affected.
Clinically, carious bone yields a soft grating sensation under the
pressure of the probe. The macerated bone presents a rough, eroded
surface.
The term _dry caries_ (_caries sicca_) is applied to that variety which
is unattended with suppuration.
_Necrosis_ is the term applied to the death of a tangible portion of
bone, and the dead portion when separated is called a _sequestrum_. The
term _exfoliation_ is sometimes employed to indicate the separation or
throwing off of a superficial sequestrum. The edges and deep surface of
the sequestrum present a serrated or worm-eaten appearance due to the
process of erosion by which the dead bone has been separated from the
living.
BACTERIAL DISEASES
The most important diseases in this group are the pyogenic, the
tuberculous, and the syphilitic.
PYOGENIC DISEASES OF BONE.--These diseases result from
infection with pyogenic organisms, and two varieties or types are
recognised according to whether the organisms concerned reach their seat
of action by way of the blood-stream, or through an infection of the
soft parts in contact with the bone.
INFECTIONS THROUGH THE BLOOD-STREAM
#Diseases caused by the Staphylococcus Aureus.#--As the majority of
pyogenic diseases are due to infection with the staphylococcus aureus,
these will be described first.
#Acute osteomyelitis# is a suppurative process beginning in the marrow
and tending to spread to the periosteum. The disease is common in
children, but is rare after the skeleton has attained maturity. Boys are
affected more often than girls, in the proportion of three to one,
probably because they are more liable to exposure, to injury, and to
violent exertion.
_Etiology._--Staphylococci gain access to the blood-stream in various
ways, it may be through the skin or through a mucous surface.
Such conditions as, for example, a blow, some extra exertion such as a
long walk, or exposure to cold, as in wading, may act as localising
factors.
The long bones are chiefly affected, and the commonest sites are: either
end of the tibia and the lower end of the femur; the other bones of the
skeleton are affected in rare instances.
_Pathology._--The disease commences and is most intense in the marrow of
the ossifying junction at one end of the diaphysis; it may commence at
both ends simultaneously--_bipolar osteomyelitis_; or, commencing at one
end, may spread to the other.
The changes observed are those of intense engorgement of the marrow,
going on to greenish-yellow purulent infiltration. Where the process is
most advanced--that is, at the ossifying junction--there are evidences
of absorption of the framework of the bone; the marrow spaces and
Haversian canals undergo enlargement and become filled with
greenish-yellow pus. This rarefaction of the spongy bone is the earliest
change seen with the X-rays.
The process may remain localised to the ossifying junction, but usually
spreads along the medullary canal for a varying distance, and also
extends to the periosteum by way of the enlarged Haversian canals. The
pus accumulates under the periosteum and lifts it up from the bone. The
extent of spread in the medullary canal and beneath the periosteum is in
close correspondence. The periosteum of the diaphysis is easily
separated--hence the facility with which the pus spreads along the
shaft; but in the region of the ossifying junction it is raised with
difficulty because of its intimate connection with the epiphysial
cartilage. Less frequently there is more than one collection of pus
under the periosteum, each being derived from a focus of suppuration in
the subjacent marrow. The pus perforates the periosteum, and makes its
way to the surface by the easiest anatomical route, and discharges
externally, forming one or more sinuses through which fresh infection
may take place. The infection may spread to the adjacent joint, either
directly through the epiphysis and articular cartilage, or along the
deep layer of the periosteum and its continuation--the capsular
ligament. When the epiphysis is intra-articular, as, for example, in the
head of the femur, the pus when it reaches the surface of the bone
necessarily erupts directly into the joint.
While the occurrence of purely periosteal suppuration is regarded as
possible, we are of opinion that the embolic form of staphylococcal
osteomyelitis always originates in the marrow.
The portion of the diaphysis which has sustained the action of the
concentrated toxins has its vitality further impaired as a result of the
stripping of the periosteum and thrombosis of the blood vessels of the
marrow, so that _necrosis_ of bone is one of the most striking results
of the disease, and as this takes place rapidly, that is, in a day or
two, the term _acute necrosis_, formerly applied to the disease, was
amply justified.
When there is marked rarefaction of the bone at the ossifying junction,
the epiphysis is liable to be separated--_epiphysiolysis_. The
separation usually takes place through the young bone of the ossifying
junction, and the surfaces of the diaphysis and epiphysis are opposed to
each other by irregular eroded surfaces bathed in pus. The separated
epiphysis may be kept in place by the periosteum, but when this has been
detached by the formation of pus beneath it, the epiphysis is liable to
be displaced by muscular action or by some movement of the limb, or it
is the diaphysis that is displaced, for example, the lower end of the
diaphysis of the femur may be projected into the popliteal space.
The epiphysial cartilage usually continues its bone-forming functions,
but when it has been seriously damaged or displaced, the further growth
of the bone in length may be interfered with. Sometimes the separated
and displaced epiphysis dies and constitutes a sequestrum.
The adjacent joint may become filled at an early stage with a serous
effusion, which may be sterile. When the cocci gain access to the joint,
the lesion assumes the characters of a purulent arthritis, which, from
its frequency during the earlier years of life, has been called _the
acute arthritis of infants_.
Separation of an epiphysis nearly always results in infection and
destruction of the adjacent joint.
Osteomyelitis is rare in the bones of the carpus and tarsus, and the
associated joints are usually infected from the outset. In flat bones,
such as the skull, the scapula, or the ilium, suppuration usually occurs
on both aspects of the bone as well as in the marrow.
_Clinical Features._--The constitutional symptoms, which are due to the
associated toxæmia, vary considerably in different cases. In mild cases
they may be so slight as to escape recognition. In exceptionally severe
cases the patient may succumb before there are obvious signs of the
localisation of the staphylococci in the bone marrow. In average cases
the temperature rises rapidly with a rigor and runs an irregular course
with morning remissions, there is marked general illness accompanied by
headache, vomiting, and sometimes delirium.
The local manifestations are pain and tenderness in relation to one of
the long bones; the pain may be so severe as to prevent sleep and to
cause the child to cry out. Tenderness on pressure over the bone is the
most valuable diagnostic sign. At a later stage there is an ill-defined
swelling in the region of the ossifying junction, with œdema of the
overlying skin and dilatation of the superficial veins.
The swelling appears earlier and is more definite in superficial bones
such as the tibia, than in those more deeply placed such as the upper
end of the femur. It may be less evident to the eye than to the fingers,
and is best appreciated by gently stroking the bone from the middle of
its shaft towards the end. The maximum thickening and tenderness usually
correspond to the junction of the diaphysis with the epiphysis, and the
swelling tails off gradually along the shaft. As time goes on there is
redness of the skin, especially over a superficial bone, such as the
tibia, the swelling becomes softer, and gives evidence of fluctuation.
This stage may be reached at the end of twenty-four hours, or not for
some days.
Suppuration spreads towards the surface, until, some days later, the
skin sloughs and pus escapes, after which the fever usually remits and
the pain and other symptoms are relieved. The pus may contain blood and
droplets of fat derived from the marrow, and in some cases minute
particles of bone are present also. The presence of fat and bony
particles in the pus confirms the medullary origin of the suppuration.
If an incision is made, the periosteum is found to be raised from the
bone; the extent of the bare bone will be found to correspond fairly
accurately with the extent of the lesion in the marrow.
_Local Complications._--The adjacent joint may exhibit symptoms which
vary from those of a simple effusion to those of a purulent _arthritis_.
The joint symptoms may count for little in the clinical picture, or, as
in the case of the hip, may so predominate as to overshadow those of the
bone lesion from which they originated.
_Separation and displacement of the epiphysis_ usually reveals itself by
an alteration in the attitude of the limb; it is nearly always
associated with suppuration in the adjacent joint.
When _pathological fracture_ of the shaft occurs, as it may do, from
some muscular effort or strain, it is attended with the usual signs of
fracture.
_Dislocation_ of the adjacent joint has been chiefly observed at the
hip; it may result from effusion into the joint and stretching of the
ligaments, or may be the sequel of a purulent arthritis; the signs of
dislocation are not so obvious as might be expected, but it is attended
with an alteration in the attitude of the limb, and the displacement of
the head of the bone is readily shown in a skiagram.
_General Complications._--In some cases a _multiplicity of lesions_ in
the bones and joints imparts to the disease the features of pyæmia. The
occurrence of endocarditis, as indicated by alterations in the heart
sounds and the development of murmurs, may cause widespread infective
embolism, and metastatic suppurations in the kidneys, heart-wall, and
lungs, as well as in other bones and joints than those primarily
affected. The secondary suppurations are liable to be overlooked unless
sought for, as they are rarely attended with much pain.
In these multiple forms of osteomyelitis the toxæmic symptoms
predominate; the patient is dull and listless, or he may be restless and
talkative, or actually delirious. The tongue is dry and coated, the lips
and teeth are covered with sordes, the motions are loose and offensive,
and may be passed involuntarily. The temperature is remittent and
irregular, the pulse small and rapid, and the urine may contain blood
and albumen. Sometimes the skin shows erythematous and purpuric rashes,
and the patient may cry out as in meningitis. The post-mortem
appearances are those of pyæmia.
_Differential Diagnosis._--Acute osteomyelitis is to be diagnosed from
infections of the soft parts, such as erysipelas and cellulitis, and, in
the case of the tibia, from erythema nodosum. Tenderness localised to
the ossifying junction is the most valuable diagnostic sign of
osteomyelitis.
When there is early and pronounced general intoxication, there is likely
to be confusion with other acute febrile illnesses, such as scarlet
fever. In all febrile conditions in children and adolescents, the
ossifying junctions of the long bones should be examined for areas of
pain and tenderness.
Osteomyelitis has many features in common with acute articular
rheumatism, and some authorities believe them to be different forms of
the same disease (Kocher). In acute rheumatism, however, the joint
symptoms predominate, there is an absence of suppuration, and the pains
and temperature yield to salicylates.
The _prognosis_ varies with the type of the disease, with its
location--the vertebræ, skull, pelvis, and lower jaw being specially
unfavourable--with the multiplicity of the lesions, and with the
development of endocarditis and internal metastases.
_Treatment._--This is carried out on the same lines as in other pyogenic
infections.
In the earliest stages of the disease, the induction of hyperæmia is
indicated, and should be employed until the diagnosis is definitely
established, and in the meantime preparations for operation should be
made. An incision is made down to and through the periosteum, and
whether pus is found or not, the bone should be opened in the vicinity
of the ossifying junction by means of a drill, gouge, or trephine. If
pus is found, the opening in the bone is extended along the shaft as far
as the periosteum has been separated, and the infected marrow is removed
with the spoon. The cavity is then lightly packed with rubber dam, or,
as recommended by Bier, the skin edges are brought together by sutures
which are loosely tied to afford sufficient space between them for the
exit of discharge, and the hyperæmic treatment is continued.
When there is widespread suppuration in the marrow, and the shaft is
extensively bared of periosteum and appears likely to die, it may be
resected straight away or after an interval of a day or two. Early
resection of the shaft is also indicated if the opening of the medullary
canal is not followed by relief of symptoms. In the leg and forearm, the
unaffected bone maintains the length and contour of the limb; in the
case of the femur and humerus, extension with weight and pulley along
with some form of moulded gutter splint is employed with a similar
object.
Amputation of the limb is reserved for grave cases, in which life is
endangered by toxæmia, which is attributed to the primary lesion. It may
be called for later if the limb is likely to be useless, as, for
example, when the whole shaft of the bone is dead without the formation
of a new case, when the epiphyses are separated and displaced, and the
joints are disorganised.
Flat bones, such as the skull or ilium, must be trephined and the pus
cleared out from both aspects of the bone. In the vertebræ, operative
interference is usually restricted to opening and draining the
associated abscess.
#Nature's Effort at Repair.#--_In cases which are left to nature_, and
in which necrosis of bone has occurred, those portions of the periosteum
and marrow which have retained their vitality resume their osteogenetic
functions, often to an exaggerated degree. Where the periosteum has been
lifted up by an accumulation of pus, or is in contact with bone that is
dead, it proceeds to form new bone with great activity, so that the dead
shaft becomes surrounded by a sheath or case of new bone, known as the
_involucrum_ (Fig. 118). Where the periosteum has been perforated by pus
making its way to the surface, there are defects or holes in the
involucrum, called _cloacæ_. As these correspond more or less in
position to the sinuses in the skin, in passing a probe down one of the
sinuses it usually passes through a cloaca and strikes the dead bone
lying in the interior. If the periosteum has been extensively
destroyed, new bone may only be formed in patches, or not at all. The
dead bone is separated from the living by the agency of granulation
tissue with its usual complements of phagocytes and osteoclasts, so that
the sequestrum presents along its margins and on its deep surface a
pitted, grooved, and worm-eaten appearance, except on the periosteal
aspect, which is unaltered. Ultimately the dead bone becomes loose and
lies in a cavity a little larger than itself; the wall of the cavity is
formed by the new case, lined with granulation tissue. The separation of
the sequestrum takes place more rapidly in the spongy bone of the
ossifying junction than in the compact bone of the shaft.
When foci of suppuration have been scattered up and down the medullary
cavity, and the bone has died in patches, several sequestra may be
included by the new case; each portion of dead bone is slowly separated,
and comes to lie in a cavity lined by granulations.
Even at a distance from the actual necrosis there is formation of new
bone by the marrow; the medullary canal is often obliterated, and the
bone becomes heavier and denser--sclerosis; and the new bone which is
deposited on the original shaft results in an increase in the girth of
the bone--hyperostosis.
[Illustration: FIG. 118.--Shaft of Femur after Acute Osteomyelitis. The
shaft has undergone extensive necrosis, and a shell of new bone has been
formed by the periosteum.]
_Pathological fracture_ of the shaft may occur at the site of necrosis,
when the new case is incapable of resisting the strain put upon it, and
is most frequently met with in the shaft of the femur. Short of
fracture, there may be bending or curving of the new case, and this
results in deformity and shortening of the limb (Fig. 119).
The _extrusion of a sequestrum_ may occur, provided there is a cloaca
large enough to allow of its escape, but the surgeon has usually to
interfere by performing the operation of sequestrectomy. Displacement or
partial extrusion of the dead bone may cause complications, as when a
sequestrum derived from the trigone of the femur perforates the
popliteal artery or the cavity of the knee-joint, or a sequestrum of the
pelvis perforates the wall of the urinary bladder.
The extent to which bone which has been lost is reproduced varies in
different parts of the skeleton: while the long bones, the scapula, the
mandible, and other bones which are developed in cartilage are almost
completely re-formed, bones which are entirely developed in membrane,
such as the flat bones of the skull and the maxilla, are not reproduced.
[Illustration: FIG. 119.--Femur and Tibia showing results of Acute
Osteomyelitis affecting Trigone of Femur; sequestrum partly surrounded
by new case; backward displacement of lower epiphysis and implication of
knee-joint.]
It may be instructive to describe _the X-ray appearances of a long bone
that has passed through an attack of acute osteomyelitis_ severe enough
to have caused necrosis of part of the diaphysis. The shadow of the dead
bone is seen in the position of the original shaft which it represents;
it is of the same shape and density as the original shaft, while its
margins present an irregular contour from the erosion concerned in its
separation. The sequestrum is separated from the living bone by a clear
zone which corresponds to the layer of granulations lining the cavity in
which it lies. This clear zone separating the shadow of the dead bone
from that of the living bone by which it is surrounded is conclusive
evidence of a sequestrum. The medullary canal in the vicinity of the
sequestrum being obliterated, is represented by a shadow of varying
density, continuous with that of the surrounding bone. The shadow of the
new case or involucrum with its wavy contour is also in evidence, with
its openings or cloacæ, and is mainly responsible for the increase in
the diameter of the bone.
The skiagram may also show separation and displacement of the adjacent
epiphysis and destruction of the articular surfaces or dislocation of
the joint.
_Sequelæ of Acute Suppurative Osteomyelitis._--The commonest sequel is
the presence of a sequestrum with one or more discharging sinuses; owing
to the abundant formation of scar tissue these sinuses have rigid edges
which are usually depressed and adherent to the bone.
_The Recognition and Removal of Sequestra._--So long as there is dead
bone there will be suppuration from the granulations lining the cavity
in which it lies, and a discharge of pus from the sinuses, so that the
mere persistence of discharge after an attack of osteomyelitis, is
presumptive evidence of the occurrence of necrosis. Where there are one
or more sinuses, the passage of a probe which strikes bare bone affords
corroboration of the view that the bone has perished. When the dead bone
has been separated from the living, the X-rays yield the most exact
information.
The traditional practice is to wait until the dead bone is entirely
separated before undertaking an operation for its removal, from fear, on
the one hand, of leaving portions behind which may keep up the
discharge, and, on the other, of removing more bone than is necessary.
This practice need not be adhered to, as by operating at an earlier
stage healing is greatly hastened. If it is decided to wait for
separation of the dead bone, drainage should be improved, and the
infective element combated by the induction of hyperæmia.
_The operation_ for the removal of the dead bone (_sequestrectomy_)
consists in opening up the periosteum and the new case sufficiently to
allow of the removal of all the dead bone, including the most minute
sequestra. The limb having been rendered bloodless, existing sinuses are
enlarged, but if these are inconveniently situated--for example, in the
centre of the popliteal space in necrosis of the femoral trigone--it is
better to make a fresh wound down to the bone on that aspect of the
limb which affords best access, and which entails the least injury of
the soft parts. The periosteum, which is thick and easily separable, is
raised from the new case with an elevator, and with the chisel or gouge
enough of the new bone is taken away to allow of the removal of the
sequestrum. Care must be taken not to leave behind any fragment of dead
bone, as this will interfere with healing, and may determine a relapse
of suppuration.
The dead bone having been removed, the lining granulations are scraped
away with a spoon, and the cavity is disinfected.
There are different ways of dealing with a _bone cavity_. It may be
packed with gauze (impregnated with "bipp" or with iodoform), which is
changed at intervals until healing takes place from the bottom; it may
be filled with a flap of bone and periosteum raised from the vicinity,
or with bone grafts; or the wall of bone on one side of the cavity may
be chiselled through at its base, so that it can be brought into contact
with the opposite wall. The method of filling bone cavities devised by
Mosetig-Moorhof, consists in disinfecting and drying the cavity by a
current of hot air, and filling it with a mixture of powdered iodoform
(60 parts) and oil of sesame and spermaceti (each 40 parts), which is
fluid at a temperature of 112° F.; the soft parts are then brought
together without drainage. As the cavity fills up with new bone the
iodoform is gradually absorbed. Iodoform gives a dark shadow with the
X-rays, so that the process of its absorption can be followed in
skiagrams taken at intervals.
These procedures may be carried out at the same time as the sequestrum
is removed, or after an interval. In all of them, asepsis is essential
for success.
The _deformities_ resulting from osteomyelitis are more marked the
earlier in life the disease occurs. Even under favourable conditions,
and with the continuous effort at reconstruction of the bone by Nature's
method, the return to normal is often far from perfect, and there
usually remains a variable amount of hyperostosis and sclerosis and
sometimes curving of the bone. Under less favourable conditions, the
late results of osteomyelitis may be more serious. _Shortening_ is not
uncommon from interference with growth at the ossifying junction.
_Exaggerated growth_ in the length of a bone is rare, and has been
observed chiefly in the bones of the leg. Where there are two parallel
bones--as in the leg, for example--the growth of the diseased bone may
be impaired, and the other continuing its normal growth becomes
disproportionately long; less frequently the growth of the diseased
bone is exaggerated, and it becomes the longer of the two. In either
case, the longer bone becomes curved. An _obliquity_ of the bone may
result when one half of the epiphysial cartilage is destroyed and the
other half continues to form bone, giving rise to such deformities as
knock-knee and club-hand.
Deformity may also result from vicious union of a pathological fracture,
permanent displacement of an epiphysis, contracture, ankylosis, or
dislocation of the adjacent joint.
#Relapsing Osteomyelitis.#--As the term indicates, the various forms of
relapsing osteomyelitis date back to an antecedent attack, and their
occurrence depends on the capacity of staphylococci to lie latent in the
marrow.
Relapse may take place within a few months of the original attack, or
not for many years. Cases are sometimes met with in which relapses recur
at regular intervals for several years, the tendency, however, being for
the attacks to become milder as the virulence of the organisms becomes
more and more attenuated.
_Clinical Features._--Osteomyelitis in a patient over twenty-five is
nearly always of the relapsing variety. In some cases the bone becomes
enlarged, with pain and tenderness on pressure; in others there are the
usual phenomena which attend suppuration, but the pus is slow in coming
to the surface, and the constitutional symptoms are slight. The pus may
escape by new channels, or one of the old sinuses may re-open.
Radiograms usually furnish useful information as to the condition of the
bone, both as it is altered by the original attack and by the changes
that attend the relapse of the infective process.
_Treatment._--In cases of thickening of the bone with persistent and
severe pain, if relief is not afforded by the repeated application of
blisters, the thickened periosteum should be incised, and the bone
opened up with the chisel or trephine. In cases attended with
suppuration, the swelling is incised and drained, and if there is a
sequestrum, it must be removed.
#Circumscribed Abscess of Bone--"Brodie's Abscess."#--The most important
form of relapsing osteomyelitis is the circumscribed abscess of bone
first described by Benjamin Brodie. It is usually met with in young
adults, but we have met with it in patients over fifty. Several years
may intervene between the original attack of osteomyelitis and the onset
of symptoms of abscess.
_Morbid Anatomy._[7]--The abscess is nearly always situated in the
central axis of the bone in the region of the ossifying junction,
although cases are occasionally met with in which it lies nearer the
middle of the shaft. In exceptional cases there is more than one abscess
(Fig. 120). The tibia is the bone most commonly affected, but the lower
end of the femur, or either end of the humerus, may be the seat of the
abscess. In the quiescent stage the lesion is represented by a small
cavity in the bone, filled with clear serum, and lined by a fibrous
membrane which is engaged in forming bone. Around the cavity the bone is
sclerosed, and the medullary canal is obliterated. When the infection
becomes active, the contents of the cavity are transformed into a
greenish-yellow pus from which the staphylococcus can be isolated, and
the cavity is lined by a thin film of granulation tissue which erodes
the surrounding bone and so causes the abscess to increase in size. If
the erosion proceeds uniformly, the cavity is spherical or oval; if it
is more active at some points than others, diverticula or tunnels are
formed, and one of these may finally erupt through the shell of the bone
or into an adjacent joint. Small irregular sequestra are occasionally
found within the abscess cavity. In long-standing cases it is common to
find extensive obliteration of the medullary canal, and a considerable
increase in the girth of the bone.
[7] Alexis Thomson, _Edin. Med. Journ._, 1906.
[Illustration: FIG. 120.--Segment of Tibia resected for Brodie's
Abscess. The specimen shows two separate abscesses in the centre of the
shaft, the lower one quiescent, the upper one active and increasing in
size.]
The size of the abscess ranges from that of a cherry to that of a
walnut, but specimens in museums show that, if left to Nature, the
abscess may attain much greater dimensions.
The affected bone is not only thicker and heavier than normal, but may
also be curved or otherwise deformed as a result of the original attack
of osteomyelitis.
The _clinical features_ are almost exclusively local. Pain, due to
tension within the abscess, is the dominant symptom. At first it is
vague and difficult to localise, later it is referred to the interior of
the bone, and is described as "boring." It is aggravated by use of the
limb, and there are often, especially during the night, exacerbations in
which the pain becomes excruciating. In the early stages there are
periods of days or weeks during which the symptoms abate, but as the
abscess increases these become shorter, until the patient is hardly ever
free from pain. Localised tenderness can almost always be elicited by
percussion, or by compressing the bone between the fingers and thumb.
The pain induced by the traction of muscles attached to the bone, or by
the weight of the body, may interfere with the function of the limb, and
in the lower extremity cause a limp in walking. The limb may be disabled
from _involvement of the adjacent joint_, in which there may be an
intermittent hydrops which comes and goes coincidently with
exacerbations of pain; or the abscess may perforate the joint and set up
an acute arthritis.
The _diagnosis_ of Brodie's abscess from other affections met with at
the ends of long bones, and particularly from tuberculosis, syphilis,
and new growths, is made by a consideration of the previous history,
especially with reference to an antecedent attack of osteomyelitis. When
the adjacent joint is implicated, the surgeon may be misled by the
patient referring all the symptoms to the joint.
The X-ray picture is usually diagnostic chiefly because all the lesions
which are liable to be confused with Brodie's abscess--gumma, tubercle,
myeloma, chondroma, and sarcoma--give a well-marked central clear area;
the sclerosis around Brodie's abscess gives a dense shadow in which the
central clear area is either not seen at all or only faintly (Fig. 121).
_Treatment._--If an abscess is suspected, there should be no hesitation
in exploring the interior of the bone. It is exposed by a suitable
incision; the periosteum is reflected and the bone is opened up by a
trephine or chisel, and the presence of an abscess may be at once
indicated by the escape of pus. If, owing to the small size of the
abscess or the density of the bone surrounding it, the pus is not
reached by this procedure, the bone should be drilled in different
directions.
[Illustration: FIG. 121.--Radiogram of Brodie's Abscess in Lower End of
Tibia.]
#Other Forms of Acute Osteomyelitis.#--Among the less severe forms of
osteomyelitis resulting from the action of attenuated organisms are the
_serous_ variety, in which an effusion of serous fluid forms under the
periosteum; and _growth fever_, in which the child complains of vague
evanescent pains (growing pains), and of feeling tired and disinclined
to play; there may be some rise of temperature in the evening.
Infection with the _staphylococcus albus_, the _streptococcus_, or the
_pneumococcus_ also causes a mild form of osteomyelitis which may go on
to suppuration.
_Necrosis without suppuration_, described by Paget under the name "quiet
necrosis," is a rare disease, and would appear to be associated with an
attenuated form of staphylococcal infection (Tavel). It occurs in
adults, being met with up to the age of fifty or sixty, and is
characterised by the insidious development of a swelling which involves
a considerable extent of a long bone. The pain varies in intensity, and
may be continuous or intermittent, and there is tenderness on pressure.
The shaft is increased in girth as a result of its being surrounded by a
new case of bone. The resemblance to sarcoma may be very close, but the
swelling is not as defined as in sarcoma, nor does it ever assume the
characteristic "leg of mutton" shape. In both diseases there is a
tendency to pathological fracture. It is difficult also in the absence
of skiagrams to differentiate the condition from syphilitic and from
tuberculous disease. If the diagnosis is not established after
examination with the X-rays, an exploratory incision should be made; if
dead bone is found, it is removed.
In typhoid fever the bone marrow is liable to be invaded by _the typhoid
bacillus_, which may set up osteomyelitis soon after its lodgment, or it
may lie latent for a considerable period before doing so. The lesions
may be single or multiple, they involve the marrow or the periosteum or
both, and they may or may not be attended with suppuration. They are
most commonly met with in the tibia and in the ribs at the
costo-chondral junctions.
The bone lesions usually occur during the seventh or eighth week of the
fever, but have been known to occur much later. The chief complaint is
of vague pains, at first referred to several bones, later becoming
localised in one; they are aggravated by movement, or by handling the
bone, and are worst at night. There is redness and œdema of the
overlying soft parts, and swelling with vague fluctuation, and on
incision there escapes a yellow creamy pus, or a brown syrupy fluid
containing the typhoid bacillus in pure culture. Necrosis is
exceptional.
When the abscess develops slowly, the condition resembles tuberculous
disease, from which it may be diagnosed by the history of typhoid fever,
and by obtaining a positive Widal reaction.
The prognosis is favourable, but recovery is apt to be slow, and relapse
is not uncommon.
It is usually sufficient to incise the periosteum, but when the disease
occurs in a rib it may be necessary to resect a portion of bone.
#Pyogenic Osteomyelitis due to Spread of Infection from the Soft
Parts.#--There still remain those forms of osteomyelitis which result
from infection through a wound involving the bone--for example, compound
fractures, gun-shot injuries, osteotomies, amputations, resections, or
operations for un-united fracture. In all of these the marrow is exposed
to infection by such organisms as are present in the wound. A similar
form of osteomyelitis may occur apart from a wound--for example,
infection may spread to the jaws from lesions of the mouth; to the
skull, from lesions of the scalp or of the cranial bones
themselves--such as a syphilitic gumma or a sarcoma which has fungated
externally; or to the petrous temporal, from suppuration in the middle
ear.
The most common is an osteomyelitis commencing in the marrow exposed in
a wound infected with pyogenic organisms. In amputation stumps,
fungating granulations protrude from the sawn end of the bone, and if
necrosis takes place, the sequestrum is annular, affecting the
cross-section of the bone at the saw-line; or tubular, extending up the
shaft, and tapering off above. The periosteum is more easily detached,
is thicker than normal, and is actively engaged in forming bone. In the
macerated specimen, the new bone presents a characteristic coral-like
appearance, and may be perforated by cloacæ (Fig. 122).
[Illustration: FIG. 122.--Tubular Sequestrum resulting from Septic
Osteomyelitis in Amputation Stump.]
Like other pyogenic infections, it may terminate in pyæmia, as a result
of septic phlebitis in the marrow.
The _clinical features_ of osteomyelitis in _an amputation stump_ are
those of ordinary pyogenic infection; the involvement of the bone may be
suspected from the clinical course, the absence of improvement from
measures directed towards overcoming the sepsis in the soft parts, and
the persistence of suppuration in spite of free drainage, but it is not
recognised unless the bone is exposed by opening up the stump or the
changes in the bone are shown by the X-rays. The first change is due to
the deposit of new bone on the periosteal surface; later, there is the
shadow of the sequestrum.
Healing does not take place until the sequestrum is extruded or removed
by operation.
_In compound fractures_, if a fragment dies and forms a sequestrum, it
is apt to be walled in by new bone; the sinuses continue to discharge
until the sequestrum is removed. Even after healing has taken place,
relapse is liable to occur, especially in gun-shot injuries. Months or
years afterwards, the bone may become painful and tender. The symptoms
may subside under rest and elevation of the limb and the application of
a compress, or an abscess forms and bursts with comparatively little
suffering. The contents may be clear yellow serum or watery pus;
sometimes a small spicule of bone is discharged. Valuable information,
both for diagnosis and treatment, is afforded by skiagrams.
[Illustration: FIG. 123.--New Periosteal Bone on surface of Femur from
Amputation Stump. Osteomyelitis supervened on the amputation, and
resulted in necrosis at the sawn section of the bone. (Anatomical
Museum, University of Edinburgh.)]
TUBERCULOUS DISEASE
The tuberculous diseases of bone result from infection of the marrow or
periosteum by tubercle bacilli conveyed through the arteries; it is
exceedingly rare for tubercle to appear in bone as a primary infection,
the bacilli being usually derived from some pre-existing focus in the
bronchial glands or elsewhere. According to the observations of John
Fraser, 60 per cent. of the cases of bone and joint tubercle in children
are due to the bovine bacillus, 37 per cent. to the human variety, and
in 3 per cent. both types are present.
Tuberculous disease in bone is characterised by its insidious onset and
slow progress, and by the frequency with which it is associated with
disease of the adjacent joint.
#Periosteal tuberculosis# is met with in the ribs, sternum, vertebral
column, skull, and less frequently in the long bones of the limbs. It
may originate in the periosteum, or may spread thence from the marrow,
or from synovial membrane.
_In superficial bones_, such as the sternum, the formation of
tuberculous granulation tissue in the deeper layer of the periosteum,
and its subsequent caseation and liquefaction, is attended by the
insidious development of a doughy swelling, which is not as a rule
painful, although tender on pressure. While the swelling often remains
quiescent for some time, it tends to increase in size, to become boggy
or fluctuating, and to assume the characters of a cold abscess. The pus
perforates the fibrous layer of the periosteum, invading and infecting
the overlying soft parts, its spread being influenced by the anatomical
arrangement of the tissues. The size of the abscess affords no
indication of the extent of the bone lesion from which it originates. As
the abscess reaches the surface, the skin becomes of a dusky red or
livid colour, is gradually thinned out, and finally sloughs, forming a
sinus. A probe passed into the sinus strikes carious bone. Small
sequestra may be found embedded in the granulation tissue. The sinus
persists as long as any active tubercle remains in the tissues, and is
apt to form an avenue for pyogenic infection.
_In deeply seated bones_, such as the upper end of the femur, the
formation of a cold abscess in the soft parts is often the first
evidence of the disease.
_Diagnosis._--Before the stage of cold abscess is reached, the localised
swelling is to be differentiated from a gumma, from chronic forms of
staphylococcal osteomyelitis, from enlarged bursa or ganglion, from
sub-periosteal lipoma, and from sarcoma. Most difficulty is met with in
relation to periosteal sarcoma, which must be differentiated either by
the X-ray appearances or by an exploratory incision.
_X-ray appearances in periosteal tubercle_: the surface of the cortical
bone in the area of disease is roughened and irregular by erosion, and
in the vicinity there may be a deposit of new bone on the surface,
particularly if a sinus is present and mixed infection has occurred; in
_syphilis_ the shadow of the bone is denser as a result of sclerosis,
and there is usually more new bone on the surface--hyperostosis; in
_periosteal sarcoma_ there is greater erosion and consequently greater
irregularity in the contour of the cortical bone, and frequently there
is evidence of formation of bone in the form of characteristic spicules
projecting from the surface at a right angle.
The early recognition of periosteal lesions in the articular ends of
bones is of importance, as the disease, if left to itself, is liable to
spread to the adjacent joint.
The _treatment_ is that of tuberculous lesions in general; if
conservative measures fail, the choice lies between the injection of
iodoform, and removal of the infected tissues with the sharp spoon. In
the ribs it is more satisfactory to remove the diseased portion of bone
along with the wall of the associated abscess or sinus. If all the
tubercle has been removed and there is no pyogenic infection, the wound
is stitched up with the object of obtaining primary union; otherwise it
is treated by the open method.
#Tuberculous Osteomyelitis.#--Tuberculous lesions in the marrow occur as
isolated or as multiple foci of granulation tissue, which replace the
marrow and erode the trabeculæ of bone in the vicinity (Fig. 124). The
individual focus varies in size from a pea to a walnut. The changes that
ensue resemble in character those in other tissues, and the extent of
the destruction varies according to the way in which the tubercle
bacillus and the marrow interact upon one another. The granulation
tissue may undergo caseation and liquefaction, or may become
encapsulated by fibrous tissue--"encysted tubercle."
[Illustration: FIG. 124.--Tuberculous Osteomyelitis of Os Magnum,
excised from a boy æt. 8. Note well-defined caseous focus, with several
minute foci in surrounding marrow.]
Sometimes the tuberculous granulation tissue spreads in the marrow,
assuming the characters of a diffuse infiltration--diffuse tuberculous
osteomyelitis. The trabecular framework of the bone undergoes erosion
and absorption--rarefying ostitis--and either disappears altogether or
only irregular fragments or sequestra of microscopic dimensions remain
in the area affected. Less frequently the trabecular framework is added
to by the formation of new bone, resulting in a remarkable degree of
sclerosis, and if, following upon this, there is caseation of the
tubercle and death of the affected portion of bone, there results a
sequestrum often of considerable size and characteristic shape, which,
because of the sclerosis and surrounding endarteritis, is exceedingly
slow in separating. When the sequestrum involves an articular surface it
is often wedge-shaped; in other situations it is rounded or truncated
and lies in the long axis of the medullary canal (Fig. 125). Finally,
the sequestrum lies loose in a cavity lined by tuberculous granulation
tissue, and is readily identified in a radiogram. This type of sclerosis
preceding death of the bone is highly characteristic of tuberculosis.
[Illustration: FIG. 125.--Tuberculous Disease of Child's Tibia,
showing sequestrum in medullary cavity, and increase in girth from
excess of new bone.]
_Clinical Features._--As a rule, it is only in superficially placed
bones, such as the tibia, ulna, clavicle, mandible, or phalanges, that
tuberculous disease in the marrow gives rise to signs sufficiently
definite to allow of its clinical recognition. In the vertebræ, or in
the bones of deeply seated joints, such as the hip or shoulder, the
existence of tuberculous lesions in the marrow can only be inferred from
indirect signs--such, for example, as rigidity and curvature in the case
of the spine, or from the symptoms of grave and persistent joint-disease
in the case of the hip or shoulder.
With few exceptions, tuberculous disease in the interior of a bone does
not reveal its presence until by extension it reaches one or other of
the surfaces of the bone. In the shaft of a long bone its eruption on
the periosteal surface is usually followed by the formation of a cold
abscess in the overlying soft parts. When situated in the articular ends
of bones, the disease more often erupts in relation to the reflection of
the synovial membrane or directly on the articular surface--in either
case giving rise to disease of the joint (Fig. 156).
[Illustration: Fig. 126.--Diffuse Tuberculous Osteomyelitis of Right
Tibia.
(Photograph lent by Sir H. J. Stiles.)]
#Diffuse Tuberculous Osteomyelitis in the shaft of a long bone# is
comparatively rare, and has been observed chiefly in the tibia and the
ulna in children (Fig. 126). It commences at the growing extremity of
the diaphysis, and spreads along the medulla to a variable extent; it is
attended by the formation of vascular and porous bone on the surface,
which causes thickening of the diaphysis; this is most marked at the
ossifying junction and tapers off along the shaft. The infection not
only spreads along the medulla, but it invades the spongy bone
surrounding this, and then the cortical bone, and is only prevented from
reaching the soft parts by the new bone formed by the periosteum. The
bone is replaced by granulation tissue, and disappears, or part of it
may become sclerosed and in time form a sequestrum. In the macerated
specimen, the sequestrum appears small in proportion to the large cavity
in which it lies. All these changes are revealed in a good skiagram,
which not only confirms the diagnosis, but, in many instances,
demonstrates the extent of the disease, the presence or absence of a
sequestrum, and the amount of new bone on the surface. Finally the
periosteum gives way, and an abscess forms in the soft parts; and if
left to itself ruptures externally, leaving a sinus. The most
satisfactory _treatment_ is to resect sub-periosteally the diseased
portion of the diaphysis.
_In cancellous bones, such as those of the tarsus_, there is a similar
caseous infiltration in the marrow, and this may be attended with the
formation of a sequestrum either in the interior of the bone or
involving its outer shell, as shown in Fig. 127. The situation and
extent of the disease are shown in X-ray photographs. After the
tuberculous granulation tissue erupts through the cortex of the bone, it
gives rise to a cold abscess or infects adjacent joints or tendon
sheaths.
[Illustration: FIG. 127.--Advanced Tuberculous Disease in region of
Ankle. The ankle-joint is ankylosed, and there is a large sequestrum in
the calcaneus.
(Specimen in Anatomical Museum, University of Edinburgh.)]
If an exact diagnosis is made at an early stage of the disease--and this
is often possible with the aid of X-rays--the affected bone is excised
sub-periosteally or its interior is cleared out with the sharp spoon and
gouge, the latter procedure being preferred in the case of the
_calcaneus_ to conserve the stability of the heel. When several bones
and joints are simultaneously affected, and there are sinuses with
mixed infection, amputation is usually indicated, especially in adults.
#Tuberculous dactylitis# is the name applied to a diffuse form of the
disease as it affects the phalanges, metacarpal or metatarsal bones. The
lesion presents, on a small scale, all the anatomical changes that have
been described as occurring in the medulla of the tibia or ulna, and
they are easily followed in skiagrams. A periosteal type of dactylitis
is also met with.
The _clinical features_ are those of a spindle-shaped swelling of a
finger or toe, indolent, painless, and interfering but little with the
function of the digit. Recovery may eventually occur without
suppuration, but it is common to have the formation of a cold abscess,
which bursts and forms one or more sinuses. It may be difficult to
differentiate tuberculous dactylitis from the enlargement of the
phalanges in inherited syphilis (syphilitic dactylitis), especially when
the tuberculous lesion occurs in a child who is the subject of inherited
syphilis.
[Illustration: FIG. 128.--Tuberculous Dactylitis.]
In the syphilitic lesion, skiagrams usually show a more abundant
formation of new bone, but in many cases the doubt is only cleared up by
observing the results of the tuberculin test or the effects of
anti-syphilitic treatment.
Sarcoma of a phalanx or metacarpal bone may closely resemble a
dactylitis both clinically and in skiagrams, but it is rare.
_Treatment._--Recovery under conservative measures is not uncommon, and
the functional results are usually better than those following upon
operative treatment, although in either case the affected finger is
liable to be dwarfed (Fig. 129). The finger should be immobilised in a
splint, and a Bier's bandage applied to the upper arm. Operative
interference is indicated if a cold abscess develops, if there is a
persistent sinus, or if a sequestrum has formed, a point upon which
information is obtained by examination with the X-rays. When a toe is
affected, amputation is the best treatment, but in the case of a finger
it is rarely called for. In the case of a metacarpal or metatarsal bone,
sub-periosteal resection is the procedure of choice, saving the
articular ends if possible.
[Illustration: FIG. 129.--Shortening of Middle Finger of Adult, the
result of Tuberculous Dactylitis in childhood.]
SYPHILITIC DISEASE
Syphilitic affections of bone may be met with at any period of the
disease, but the graver forms occur in the tertiary stage of acquired
and inherited syphilis. The virus is carried by the blood-stream to all
parts of the skeleton, but the local development of the disease appears
to be influenced by a predisposition on the part of individual bones.
Syphilitic diseases of bone are much less common in practice than those
due to pyogenic and tuberculous infectious, and they show a marked
predilection for the tibia, sternum, and skull. They differ from
tuberculous affections in the frequency with which they attack the
shafts of bones rather than the articular ends, and in the comparative
rarity of joint complications.
_Evanescent periostitis_ is met with in acquired syphilis during the
period of the early skin eruptions. The patient complains, especially at
night, of pains over the frontal bone, ribs, sternum, tibiæ, or ulnæ.
Localised tenderness is elicited on pressure, and there is slight
swelling, which, however, rarely amounts to what may be described as a
_periosteal node_.
In the later stages of acquired syphilis, _gummatous periostitis and
osteomyelitis_ occur, and are characterised by the formation in the
periosteum and marrow of circumscribed gummata or of a diffuse gummatous
infiltration. The framework of the bone is rarefied in the area
immediately involved, and sclerosed in the parts beyond. If the
gummatous tissue degenerates and breaks down, and especially if the
overlying skin is perforated and septic infection is superadded, the
bone disintegrates and exhibits the condition known as _syphilitic
caries_; sometimes a portion of bone has its blood supply so far
interfered with that it dies--_syphilitic necrosis_. Syphilitic
sequestra are heavier and denser than normal bone, because sclerosis
usually precedes death of the bone. The bones especially affected by
gummatous disease are: the skull, the septum of the nose, the nasal
bones, palate, sternum, femur, tibia, and the bones of the forearm.
_In the bones of the skull_, gummata may form in the peri-cranium,
diploë, or dura mater. An isolated gumma forms a firm elastic swelling,
shading off into the surroundings. In the macerated bone there is a
depression or an actual perforation of the calvaria; multiple gummata
tend to fuse with one another at their margins, giving the appearance of
a combination of circles: these sometimes surround an area of bone and
cut it off from its blood supply (Fig. 130). If the overlying skin is
destroyed and septic infection superadded, such an isolated area of bone
is apt to die and furnish a sequestrum; the separation of the dead bone
is extremely slow, partly from the want of vascularity in the sclerosed
bone round about, and partly from the density of the sequestrum. In
exceptional cases the necrosis involves the entire vertical plate of the
frontal bone. Pus is formed between the bone and the dura (suppurative
pachymeningitis), and this may be followed by cerebral abscess or by
pyæmia. Gummatous disease in the wall of the orbit may cause
displacement of the eye and paralysis of the ocular muscles.
[Illustration: FIG. 130.--Syphilitic Disease of Skull, showing a
sequestrum in process of separation.]
On the inner surface of the skull, the formation of gummatous tissue may
cause pressure on the brain and give rise to intense pain in the head,
Jacksonian epilepsy, or paralysis, the symptoms varying with the seat
and extent of the disease. The cranial nerves may be pressed upon at the
base, especially at their points of exit, and this gives rise to
symptoms of irritation or paralysis in the area of distribution of the
nerves affected.