Tuberculous disease in bone is characterised by its insidious onset and slow progress, and by the frequency with which it is a.s.sociated 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 a.s.sume 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 pa.s.sed 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 a.s.sociated abscess or sinus. If all the tubercle has been removed and there is no pyogenic infection, the wound is st.i.tched 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 trabeculae 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."
[Ill.u.s.tration: FIG. 124.--Tuberculous Osteomyelitis of Os Magnum, excised from a boy aet. 8. Note well-defined caseous focus, with several minute foci in surrounding marrow.]
Sometimes the tuberculous granulation tissue spreads in the marrow, a.s.suming the characters of a diffuse infiltration--diffuse tuberculous osteomyelitis. The trabecular framework of the bone undergoes erosion and absorption--rarefying ost.i.tis--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 ca.n.a.l (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.
[Ill.u.s.tration: 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 vertebrae, 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).
[Ill.u.s.tration: 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 sh.e.l.l, 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.
[Ill.u.s.tration: 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.
[Ill.u.s.tration: 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.
[Ill.u.s.tration: 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 periost.i.tis_ 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, tibiae, or ulnae.
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 periost.i.tis and osteomyelitis_ occur, and are characterised by the formation in the periosteum and marrow of circ.u.mscribed 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, diploe, 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 pyaemia. Gummatous disease in the wall of the orbit may cause displacement of the eye and paralysis of the ocular muscles.
[Ill.u.s.tration: 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.
_In the septum of the nose, the nasal bones, and the hard palate_, gummatous disease causes ulceration, which, beginning in the mucous membrane, spreads to the bones, and being complicated with septic infection leads to caries and necrosis. In the nose, the disease is attended with stinking discharge (ozna), the extrusion of portions of dead bone, and subsequently with deformity characterised by loss of the bridge of the nose; in the palate, it is common to have a perforation, so that the air escapes through the nose in speaking, giving to the voice a characteristic nasal tone.
_Syphilitic disease of the tibia_ may be taken as the type of the affection as it occurs _in the long bones_. Gummatous disease in the periosteum may be localised and result in the formation of a well-defined node, or the whole shaft may become the seat of an irregular nodular enlargement (Fig. 132). If the bone is macerated, it is found to be heavier and bulkier than normal; there is diffuse sclerosis with obliteration of the medullary ca.n.a.l, and the surface is uneven from heaping up of new bone--hyperostosis (Fig. 131). If a periosteal gumma breaks down and invades the skin, a syphilitic ulcer is formed with carious bone at the bottom. A central gumma may eat away the surrounding bone to such an extent that the shaft undergoes pathological fracture. In the rare cases in which it attacks the articular end of a long bone, gummatous disease may implicate the adjacent joint and give rise to syphilitic arthritis.
[Ill.u.s.tration: FIG. 131.--Syphilitic Hyperostosis and Sclerosis of Tibia, on section and on surface view.]
_Clinical Features._--There is severe boring pain--as if a gimlet were being driven into the bone. It is worst at night, preventing sleep, and has been ascribed to compression of the nerves in the narrowed Haversian ca.n.a.ls.
The _periosteal gumma_ appears as a smooth, circ.u.mscribed swelling which is soft and elastic in the centre and firm at the margins, and shades off into the surrounding bone. The gumma may be completely absorbed or it may give place to a hard node. In some cases the gumma softens in the centre, the skin becomes adherent, thin, and red, and finally gives way.
The opening in the skin persists as a sinus, or develops into a typical ulcer with irregular, crescentic margins; in either case a probe reveals the presence of carious bone or of a sequestrum. The health may be impaired as a result of mixed infection, and the absorption of toxins and waxy degeneration in the viscera may ultimately be induced.
A _central gumma_ in a long bone may not reveal its presence until it erupts through the sh.e.l.l and reaches the periosteal surface or invades an adjacent joint. Sometimes the first manifestation is a fracture of the bone produced by slight violence.
In radiograms the appearance of syphilitic bones is usually characteristic. When there is hyperostosis and sclerosis, the shaft appears denser and broader than normal, and the contour is uneven or wavy. When there is a central gumma, the shadow is interrupted by a rounded clear area, like that of a chondroma or myeloma, but there is sclerosis round about.
_Diagnosis._--The conditions most liable to be mistaken for syphilitic disease of bone are chronic staphylococcal osteomyelitis, tuberculosis, and sarcoma; and the diagnosis is to be made by the history and progress of the disease, the result of examination with the X-rays, and the results of specific tests and treatment.
_Treatment._--The general health is to be improved by open air, by nourishing food, and by the administration of cod-liver oil, iron, and a.r.s.enic. Anti-syphilitic remedies should be given, and if they are administered before there is any destruction of tissue, the benefit derived from them is usually marked.
Radiograms show the rapid absorption of the new bone both on the surface and in the marrow, and are of value in establishing the therapeutic diagnosis.
In certain cases, and particularly when there are destructive changes in the bone complicated with pyogenic infection, specific remedies have little effect. In cases of persistent or relapsing gummatous disease with ulceration of skin, it is often necessary to remove the diseased soft parts with the sharp spoon and scissors, and to gouge or chisel away the unhealthy bone, on the same lines as in tuberculous disease.
When hyperostosis and sclerosis of the bone is attended with severe pain which does not yield to blistering, the periosteum may be incised and the sclerosed bone perforated with a drill or trephine.
#Lesions of Bone in Inherited Syphilis.#--_Craniotabes_, in which the flat bones of the skull undergo absorption in patches, was formerly regarded as syphilitic, but it is now known to result from prolonged malnutrition from any cause. _Bossing of the skull_ resulting in the formation of Parrot"s nodes is also being withdrawn from the category of syphilitic affections. The lesions in infancy--epiphysitis, bossing of the skull, and craniotabes--have been referred to in the chapter on inherited syphilis.