Ch17 Diseases of Bones and Joints_ Inf

7/27/2019 Ch17 Diseases of Bones and Joints_ Inf

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CHAPTER 17

ACUTE OSTEOMYELITIS

CHRONIC OSTEOMYELITISACUTE SUPPURATIVE ARTHRITIS

TUBERCULOUS ARTHRITIS AND OSTEOMYELITIS

TUBERCULOUS TENOSYNOVITIS

FURTHER READING

ACUTE OSTEOMYELITIS

Acute osteomyelitis used to be a common, serious and often fatal disease in

children. In developed countries there has been a fall in the incidence of the

disease, probably due to an improvement in the general health of children, but over

recent decades the incidence has remained unchanged. At the same time,

antibiotics have made the disease less serious: it need never now be fatal and

should be curable.

Aetiology. The bacteria reach the bone by the bloodstream.Aprimary focus may

be obvious in the form of a boil or an infected graze, but often there is no obvious

source of infection. Rarely, the disease may be secondary to a frank septicaemia orpyaemia. More commonly, the blood borne infection takes the form of a

bacteraemia.

It has been suggested that a lowered general resistance on the part of the patient,

and local trauma, may predispose to this disease but the evidence in support of

these suggestions is unconvincing.

In 80 per cent of cases the causative organism is Staphylococcus aureus, which is


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almost invariably resistant to penicillin. Other organisms that may be responsible

include the streptococcus, pneumococcus,Haemophilus influenzae (common under

the age of 2), Staph. albus and the salmonellas.

Pathology. The disease nearly always begins in the metaphysis. The infective

process progresses through the thickness of the cortex via the Haversian canals

and, as it does so, it causes thrombosis of the vessels in the bone. By the time the

infection reaches the

Ciopton Havers, 16501702. London attaomist and physician.

Balm1 & 1ff.e~ Sho,t Pmdic, ofS~rgom, 22nd edition. Edited by Charles V.

Mann, R.C.G. Russeil and NS. Williams. Published in 1995 by Chapman &

Hall, London ISBN 0412 494936 (HB) and 0412 543~J I (PB)subperiosteal region of the bone, a variable amount of the cortex may have been

infarcted. In the first 24 or 48 hours after the onset of the infection an

inflammatory exudate forms deep to the periosteum, elevating the membrane from

the bone. Periosteal elevation is painful and, since the petiosteurn is inelastic, the

inflammatory exudate deep to it is under tension. The patient rapidly develops

marked toxic signs. Approximately 24 hours after the first symptom, frank pus

develops subperiosteally. The infective process rarely crosses the growth plate as it

contains no blood vessels and the periosteutn is finnly attached to the plate at this

level. The inflammatorc process progresses along the length of the medulla causing

venous and arterial thrombosis as it does so. Subpertosteally, pus tracks both

longitudinally and circumferentially around the bone, stripping the periosteum and

interrupting the periosteal vessels. Thus progressisclv larger areas of the cortex

become infarcted and involved in the inflammatory process.

In the absence of treatment, pus finally bursts through the peniosteum and tracks

through the mtasdes to present subcutaneously. Eventually, the skin breaks down

and pus discharges from a sinus which connects the bone with the skirt surface.

The bone infarct in acute osteomyelitis is known as a sequestrum. Surrounding the

sequestrum, the elevated periosteum lays down new bone which entombs the dead

bone within. The ensheathing mass of new bone is known as the involucruni. In theplaces where pus has broken through the periostettm, sinuses develop which are

represented in the involucrum by holes known as doacas (Latin. a drain). The

development of such advanced pathology is now rarely seen since modem

treatment, if adequate and given in time, aborts the disease before pus has formed,

and certainly before a significant amount of bone has died.

Two factors are responsible for the chronicity of the disease: the presence of


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dead, infected bone which cannot be resorbed; and the fact that the intraosseous

abscess cavity cannot be obliterated because it has rigid bony walls. As a

consequence of these factors, the bodys normal defence mechanisms together with

any antibiotics that may be given therapeutically, are unable to reach all the

bacteria in the bone. Accordingly, although the disease process may be sterilised in

the living bone, recurrence is always likely.

Clinical features. Pain is the presenting symptom. It is essential that an accurate

history is taken so that the onset of the first complaint of local pain can be timed

exactly. The significance of this feature of the history is discussed under

Treatment. A history of trauma

267

is sometimes given and this may obscure the true diagnosis. The pain gradually

increases in severity, and the child becomes increasingly febrile and toxic, at a ratedependent upon the toxicity and virulence of the infective organism. It is usual for

the mother to seek medical advice within 48 hours of the onset of the first

symptom.

Physical signs. The essential physical sign is localised

bony tenderness. When the doctor first examines the child, the child is likely to be

irritable and to resent examination. It is imperative that the clinician should be

patient, and gently palpate the childs limbs until the exact area of maximum

tenderness has been identified. If this tenderness lies over the metaphysis of a long

bone, the diagnosis of acute osteomyelitis should be presumed (and treated) until it

can be proved otherwise. The adjacent joint may contain an effusion, raising the

differential diagnosis of suppurative arthritis. The joint itself however is not tender

and although tlte child resists movement of the limb, with patience it is possible to

demonstrate that some movement of the joint is allowed. This contrasts with acute

suppurative arthritis in which absolutely sw movement is permitted. The tempera-

ture is raised, often markedly so, and an associated increase in the pulse rate

occurs. Some days after the onset of the first symptom, noticeable swelling and

heat m~sy be detected in addition to tenderness.

Finally, the area of the abscess (for such it is by this time) is fluctuant.

It is absolutely essential that blood cultures should be undertaken beforeantibiotic treatment is commenced. The child should he searched minutely for

possible primary foci of infection, and if these are found they should be cultured.

Special investigations. Other investigations are of rio diagnostic value early in the

disease. The erythrocyte sedimentation rate (ESR) and white cell count are usually

raised but this is entirely nonspecific.


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Radiology. There are no abnormal radiological features in the first few days of the

infection. As times goes by, new bone can be seen deposited by the elevated

periosteum. but this sign does not appear until more than 10 days after the onset of

the disease and will then be observed whether or not the disease has been

sterilised: it depends entirely upon the presence or absence of periosteal elevation.

Some rarefaction in the bone due to local hyperaemia will also occur after 2 or 3

weeks, but again does not distinguish continuing osteomyelitis from the sterilised

disease. The radiological appearances of chronic osteomyelitis are dealt with later

in this chapter.

Isotope bone scanningwith ~Tc-labelled phosphonate compounds is useful in

cases where the diagnosis is difficult but should not be used where the

investigation may delay treatment in cases where the diagnosis is obvious. It may

help:

where there is difficulty in localisation;

where bone infection must be distinguished from contiguous soft-tissue infection; when joint injection must be distinguished from transient synovitiS.

It is of little use in neonates.

Treatment. The child is admitted to hospital and the limb splinted in such a way

that eas access to the

tender area is retained. The outline of the tender area is marked on the skin.

If the patient is first seen within 48 hours of the appearance of the first

symptoms, antibiotic treatment is begun immediately after appropriate samples

have been taken for blood culture. Acute osteomyelitis is one of the few diseases in

which it is justifiable to begin antibiotic treatment without waiting for bacterial

sensitivity, a peculiarity which stems from the fact that, if the disease can be

sterilised within the first 48 hours, complete resolution can be guaranteed. If

sterilisation fails, or is not attempted in this period, the disease ma) become

chronic, so generating lifelong disability and a possible cause of death. The great

majority of the bacterial isolates from osteomyelitis are Staph. aureus and

cloxadilhin should be administered at a daily dosage of 200 mg/kg in divided doses

intravenously until the child is clinically well, has no fever and the local signs havedecreased. Oral therapy with fludoxad]lin 100 mg/kg daily can then be given.

Benzyl penicillin can be given if either streptococci or pneumococci are isolated

but, as they are relatively rare and are usually sensitive to cloxacillin, there is no

need to use this initially. For penicillin-hypersensitive patients, a cephalosporin or

fusidic acid and erythromycin may be given instead. In children under 3 years,H.

infiuenzae is often responsible and especially affects the small bones of the hands


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and feet. Daily ampicillin 150 mg/kg intravenously is recommended.

Unfortunately, antibiotic resistance among organisms causing osteomyelitis creates

problems. The staphylococci are usually resistant to benzyl penicillin. Most strains

ofH. infiuenzae are currently susceptible to ampicillin, but if failure to respond is

thought to be due to a resistant organism, chloramphenicol should be substituted,

with the precautions outlined in Chapter 6. Other antibiotics may be substituted if

they are indicated by the sensitivity tests.

If the patient is first seen 48 hours or snore after the onset of the first symptom,

the possibility arises that pus is present. If pus is present, it may be sterilised by

antibiotics, but the general surgical principle that an abscess requires surgical

evacuation applies to bone as in other tissues. The presence of pus may be difficult

or impossible to detect with certainty, since fluctuation is late to develop.

Fluctuation cannot be demonstrated in the early stages of abscess formation

because the periosteal membrane is tense, the involved bone is often deep to

muscle, and the area is too tender to palpate firmly. Therefore the surgeon has torely upon his or her general impression as to the severity of the disease.

Knowledge of its duration may be crucial in deciding either to treat the patient

initially with antibiotics, or to combine this therapy with incision of the tender

area.

If it is decided to rely on antibiotic therapy alone in the belief that no pus is

present, antibiotics should be given and the effect of this treatment upon the toxic

268

signs and upon local tenderness should be watched very closely. If the antibiotic is

controlling the disease, and if no pus is present, the temperature will subside and

become normal within 2 or 3 days and the local tenderness will progressively

disappear. If, on the other hand, the antibiotics are inappropriate to the sensitivities

of the organism or pus is present, the temperature is likely to settle but not

completely; spikes up to 380C will continue. If this occurs, the tender area must be

explored surgically with a view to evacuating pus if any is present and to obtaining

the organism for culture and sensitivity.

Operation. Operation is carried out under general anaesthesia and is preceded by

exsanguination of the limb by elevation and the use of an inflatable tourniquet. An

incision is made over the tender area and carried down to the bone where pus isusually found deep to the penosteum. The abscess cavity is fully opened and the

pus evacuated. A swab is taken for culture and sensitivity at this stage. There is

controversy as to whether or not this procedure should be followed by drilling the

cortex to enable any pus that may be present in the medullary cavity to drain to the

surface. The wound is then closed with intermpted sutures over a closed, sterile

suction drain. Antibiotics and local splintage are continued postoperatively.


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Complications. These may be divided into two types, general and local. The

general complications are septicaentia and pyaemia, which may give nse to

metastatic abscesses. Either complication, if uncontrolled, may prove fatal.

Amyloid diseae may develop as a complication of chronic osteomyelitis (below).

The local complications include:

secondary involvement of the joint if the epiphyseal line is intraarticular, for

example, the hip joint in association with osteomyelitis of the proximal femur;

spontaneous fracture, which is rare provided the limb is splinted and the disease

adequately treated;

deformity which, surprisingly, is rare;

chronic osteomyelltis.

Differential diagnosis.Acute suppurative arthritis. The sepsis is intra-articular,

and therefore the patient allows no movement of the joint. in the sympathetic

effusion associated with acute osteomyelitis, a certain range of painless movementcan usually be obtained if the joint is moved gently. The maximum tendemess is

near the end of the bone in osteomyelitis rather than over the joint as in suppurative

arthritis.

Acute rheumatic arthritis is usually polyarticular and fleeting in any one joint.

There is a history of a sore throat and cardiovascular signs are often present.

Haemarfhrosis may occur in haemophilia. The patient is usually a known

haemophiliac and aspiration, if necessary, reveals blood.

Scurvy. Subperiosteal haematomata are sometimes very tender and, if near an

epiphrsis, may be confused with acute osteomyelitis.

Acute exanthentas and typhoid fryer. These conditions may be suspected on

account of the profoundly toxic and even comatose condition of the patient. If

careful palpation over a locallsed area of the end of a long bone induces resentful

movements or moaning, the possibility of osteomyelitis should be considered.

Typhoid is a likely cause of osteomyelitis in a child with sickle-cell anaemia.

Ewings tumour. See Chapter 18.

Acute traumatic osteomyelitis

This condition arises as a result of infected wounds, e.g. compound fractures, andoperations on bones. The constitutional disturbances are less severe than in acute

(infective) osteomyelitis, as the causative wound provides some measure of

drainage. Treatment consists of more extensive opening of the wound, removal of

dead bone, and antibiotics. The prevention of this

condition depends upon adequate initial treatment of compound fractures (Chapter

14) and upon sterile operating conditions.


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Subacute osteomyelitis

There is wide variation in the clinical presentation of acute osteomyelitis and less

severe forms are seen. This ma) be due to an alteration in the virulence of the

causative organism, increasing resistance of the host or the use of antibiotics.

There may be few systemic signs but there is always bony tenderness.

Investigations must include a full blood count, blood and urine culture, and

suitable radiographs. An ESR is important to provide a baseline for treatment

which is along the lines indicated for acute osteomvelitis.

CHRONIC OSTEOMYELITIS

Pathology. Acute haematogenous osteomyelitis may develop into chronic

osteomyelitis if early treatment is either not available, or is inadequate, so that

infected bone dies to form a sequestrum (Fig. 17.1). The disease may take twoforms. The pathology of the more common variety in which a large volume of

bone is involved (Fig. 17.2) has been described under acute osteomyelitis. The

incidence of this condition has been greatly reduced by modern treatment of the

acute infection but some cases remain as a legacy of the era before antibiotics, and

more will probably occur in the future if the acute infection is inadequately treated.

Fig. 17.1 Chronic osteomyelitis of the femur with a cavity containing a


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sequestrum.

The second variety is known as Brodies abscess. The infection in this form of the

disease is closely contained so as to create a chronic abscess within the bone

composed of pus or jelly-like granulation tissue surrounded by sclerotic bone. The

lesion may be the sequel to a pyogenic septicaemia from which the patient has

recovered, leaving a bone abscess which may remain dormant for years. On the

other hand, it may be found in a patient who is known to have had osteomyelitis

(but not septicaemia) affecting a bone other than the one in which the Brodies

abscess is discovered.

Clinical features. Chronic osteomyelitis may remain quiescent for months or

years, but from time to time acute or subacute exacerbations occur. An exacer-

bation is ushered in with constitutional upset and local

SirBenjamin Brodie. 17831862. Surgeon, St Georges Hospital. Lenders,

England.

269

WY.

FIg. 17.3 Bradies abscess of the lower end of the tibia, revealing a band

of sclerosis surroundU ing a central lucent area.

evidence of inflammation, which may culminate in a

discharge of pus, often from a pre-existing sinus. A

radiograph sometimes reveals a sequestrum, and a

sinogram may delineate an abscess cavity in the bone

(Fig. 17.3).

A Brodies abscess causes intermittent local pain and occasionally transitory

effusions in the adjacent joint during an exacerbation. Examination may reveal

tenderness and thickening of the bone. A radiograph is diagnostic. The amount of

bony sclerois is variable, ranging from dense sclerosis extending a considerable

distance round the cavity to, more commonly, a faint line of sclerosis at the

junction of the abscess with the cancellous bone.

The chronicity of a Brodies abscess is the result of the physical characteristics ofbone, because the abscess can never close by collapse of the walls as happens in

soft tissues. Moreover, the infection kills the hard, bony walls of the abscess and

provokes new bone deposition, thus preventing leucocytes, antibodies and

antibiotics from reaching the contents of the cavity.

Treatment of exacerbations in chronic osteomyelitis consists of irnmobilisation of

the limb and the administration of antibiotics. On this regime, the exacerbation


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often subsides, but only to recur again later.

Surgical intervention in chronic osteomyelitis has as its objective the removal of

dead bone and the elimination of dead space. Dead bone in the form of a

sequestrurn may he detected by probing a sinus or

by a radiograph. Seams of dead bone dispersed within living bone cannot be

detected with certainty but may be suspected if a radiograph shows an area of

sclerosis. An appropriate antibiotic (which is chosen in the light of the sensitivity

of the causative organism) is administered for some days before operation. Access

to the bone is usually gained through a previous scar. The soft tissues are stripped

from the bone, and the involucrum is removed to reach the sequestrum. If a cavity

is present, the overhanging walls are removed with an osteotome, until it is

saucerised. Sclerotic bone is removed en bloc if this is practicable. The wound is

drained and closed in such a way as to eliminate dead space as far as possible.

Modern approaches to this problem include insertion of gentanucin-impregnated

beads following debridement of the affected area. These are removed 14 days laterand the dead space obliterated by packing the cavity with cancellous bone chips, or

filling it with a local muscle flap.

So difficult is it to guarantee that an operation will cure chronic osteomyelitis

affecting a large volume of bone, that operative intervention is not to be considered

lightly unless a sequestrum is known to be present. If, however, a sequestrum is

present and is removed, sinuses will often close and the disease may be cured. If

only a cavity or sclerosis is present in the bone without a sequestrum, the attempt

to saucerise may fail and still leave a sinus. There are many patients for whom, if

the discharge is slight and easily controlled by a dressing, it is preferable to retain

the sinus and dressings permanently. Amyloid disease need be feared only when

copious discharge of pus has persisted for some years.

Amputation may be advisable if exacerbations are frequent or prolonged, to rid

the patient of recurring periods of painful disability, and to forestall the onset of

amyloid disease.

A Brodies abscess should be treated by surgical evacuation and curettage of thecavity under antibiotic cover followed, if the cavity is of moderate size, by packing

with cancellous bone chips.

ACUTE SUPPURATIVE ARTHRITIS


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Like acute osteomvelitis, this used to be a common disease especially in children,

but it is now rare. Acute infection of a joint occurs as a result of the following:

Direct infection, as by a penetrating wound or a compound fracture which

involves the joint.

Local extension, from some neighbouring focus, such as acute arthritis of the hip

joint from osteomyelltis of the femoral neck.

Blood-borne infection, the usual organism being the streptococcus, staphyloccus.

pneumococcus and, less commonly, the gonococcus and salmonellas.

The knee joint, owing to its large size and exposed position, is the commonest joint

to be involved by penetrating wounds, whereas strppurative arthritis from blood-

home infections is the more common cause in other joints.

Clinical features. The patient complaints of steadily increasing pain, inability to

move the joint, arid malaise. On examination, the patient is often severlv toxic with

a raised temperature and pulse rate. The joint is held in the position of its greatest

capadty (11w position of ease) and, if subcutaneous, it can he seen to be swollen(Table 17.1). Palpation reveals increased heat, tenderness ar,d an

Fig. 17.2 Chronic osteomyelitis of the forearm of a child due to a

mixed infection (Staph. aureus and Strep. pyogenes) (Department of

Radiology. Royal London Hospital. London, England.)

Table 17.1 Suppurative arthritis: physical signs and optimum positions for Joint

ankylosis

Joint Position of ease Site of maximum swelling

Position for ankylosis

Shoulder Adducted Under the deltoid along the tendon

of 4050 of abduction, with elbow joint just

the biceps and in the axilla anterior to the coronal plane

and hand in

front of the mouth

ElbowFlexed at a right- On either side of the triceps tendon

Flexed at a right-angle semipronated. If

angle and pronated both sides, one elbow at 75 of

extension,

the other at 135. These positions

enablethe patient to reach the external

orifices.

Wrist Slight flexionUnder extensor and flexor tendons Slightly dorsiflexed to

allow a firm grasp

Hip Flexed. adducted and Upper part of Scarpas triangle

2030 of flexion to allow sitting, and in


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externally rotated neutral position as regards

abduction and

rotation

Knee Flexed Suprapatellar bursa and either side of51 0 of flexion to

allow foot to clear

patellar tendon ground in walking

Ankle Slightly plantarflexed Anteriorly and on either side of the

At a right-angle

(and inverted at the Achilles tendon

subtalar joint)

effusion. Movements are prevented absolutely by muscular spasm, and attempts at

either active or passive movement cause severe pain.

Treatment. hnmobilisafion. The joint must be immobilised until the infection has

been cured. As any case of suppurative arthritis may be followed by ankylosis, it isthe duty of the surgeon to anticipate this possibility by immobilising the joint in the

best position for ankylosis, i.e. the position of optimum function, as indicated in

Table 17.1. The limb is supported and fixed by a suitable splint or other appliance

in the correct position, an anaesthetic being administered if necessary. Traction is

used in cases of septic arthritis of the hip to prevent dislocation.

Antibiotics are administered systemically as in acute osteomyelitis.Aspiration is

employed for both diagnostic and therapeutic reasons. The nature of the fluid can

be ascertained, and the organism cultured to obtain its antibiotic sensitivity.

Aspiration reduces the tension within the joint, thereby relieving pain, and limiting

the stretching of ligaments and capsule. It has the disadvantage that a previously

uninfected sympathetic effusion may be infected if the needle traverses a septic

focus on its way into the joint. On balance, the advantages outweigh this

disadvantage. If frank pus is aspirated, the joint is opened (see below).

Aspiration and injection. After fluid has been aspirated, antibiotics maybe injected

into the joint. Repeated injections of antibiotic into a joint are unnecessary, since

systemic administration is adequate.

Arthrotomy and drainage is only done if the joint is found on aspiration to contain

frank pus, or if bone destruction has involved the articular surfaces so that some

degree of ankylosis is all that can be expected when healing has occurred. The jointis opened, washed out and dosed suction drains are placed down to the synovial

cavity. This technique is nowada~s less often needed, because the disease, if

diagnosed early, can he treated by antibiotics and aspiration. but is imperative in a

childs hip because the vascularity of the temoral epiphysis is at risk with

increasing pressure in the joint. This must be relieved promptly by open operation.

Extra-articular abscesses sometimes require to be opened and drained. In the case


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of the knee joint, pus is particularly liable to track upwards beneath the quadriceps,

where its presence may be overlooked.

Excision.Nowadays this is rarely required. but if the condition of the patient

deteriorates in spite of treatment, or if suppuration is prolonged, drastic surgical

ablation of the diseased bone is necessary.

Complications.Early complications include destruction of articular cartilage,

pathological dislocation, and necrosis of the epiphysis resulting from damage to

the blood supply (especially in the case of the proximal femoral epiphysis).Late

complications Include secondary degenerative osteoarthrit.s, joint stiffness and

fibrous or, particularly, bony ankylosis.

TUBERCULOUS ARTHRITIS AND

OSTEOMYELITIS

Pathology. Bone and joint tuberculosis is haematogenous in origin. The primary

focus is related either to the gastrointestinal tract if the disease has been acquiredby the ingestion of bovine mycobacteria (in infected milk), or to the lungs if the

disease has been caused by inhalation of the human strain. With the eradication of

bovine tuberculosis in dairy herds and of human pulmonary tuberculosis, bone and

joint tuberculosis became rare in the UK, but there has been a recent increase in

incidence in certain cities with a large immigrant population. In countries where

bone and joint tuberculosis is still common, it is usually due to the human strain of

the organism, since little milk is drunk.

The disease starts either in thesynovial membrane or in intra-articular bone. The

disease may develop in any synovial joint (especially those with extensive synovial

membranes such as the hip and knee), in tendon synovial sheaths (especially those

of the finger flexors), or in bursae (such as that overlying the greater trochanter).

The spine is also commonly involved and tuberculosis here carries the eponymous

description of Potts disease. The vertebral bodies almost always those of two

neighbouring vertebrae are involved first.

Typical tubercles develop in the synovial membrane, which becomes bulky and

inflamed, and an infected effusion collects in the synovial cavity. If the infection

can be diagnosed and cured at this stage, full function may be restored to the joint.

If, on the other hand, the pathological process progresses, srticular cartilage isdestroyed and the adjacent bone is involved. At this stage, some loss of function is

certain since healing leaves a fibrous ankylosis, not two health) surfaces of

articular cartilage separated by the synovial

Percita! Pot), )714.88. Surgeon, StBartholomews Hospital, England. Antonic


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Searpa, b. 1747. Italian anatornist and surgeon.

271

cavity. 11 the disease starts in intra-articular hone, the synovial membrane rapidly

becomes involvedFor practical purposes, involvement of both the synozjal

membrane and of the bon, must be asszinted when a diagnosis is made of

tuberculous arthritis.

In the spine, the diagnosis is rarely made until the bodies of two neighbouring

vertebrae are significantly involved (Fig. 17.4) so that the end result, at best, is the

replacement of an intervertebral disc and of the diseased bone by fibrous tissue.

Should treatment for spinal disease b~ delayed, abscess formation occurs and the

vertebral bodies collapse (Fig. 17.4). The pus tracks along tissue planes to present

superficially in places often distant from the involved vertebrae, e.g. pus arising

from D~ L1 ma) track along the psoas muscle to present in the groir. brining a

cold abscess.

Vertebral collapse produces forward angulation of the spine (a kyphos, Fig. 17.5)and the combination of pus formation and spinal angulation compresses and may

damage the spinal cord. The cord may also be prejudiced bc interference csith its

blood supply from the anterior spinal artenes. As a c~msequcence paraplegia

(Potts paraplegia) may develop.

Tuberculosis of the shaft of a tong bone occurs in miliary tuberculosis, but is rare.

(b,

Fig. 17.4 Tuberculosis of the 11th s;ict 12th oorsai vertebrae. (a) Collapse ~1 two

vertebral bods n;~ a wedge; )b) perispinsl abscess chadoa.

(a)

L

r

(b)

Fig. 17.5 (a) Tuberculosis of the spine. L1 and L2 (1) have collapsed to produce

wedging (arid hence kyphos). A further tuberculosis lesion is present in O~ (2); (b)

the clinical appearance of kyphos due to tuberculosis of the spine. (From London

Hospital Museum, London, England.)

Clinical features

Symptoms. These may arise from the diseased joint, from the primary focus, and

from the systemic effects of the disease.


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The patient complains of an ache in the joint, at first mild in nature, which is

worse on exertion or at night. If the joint is subcutaneous, it may be noticed to be

swollen, a feature made more obvious by the wasting of the associated muscles. As

the disease progresses, the joint becomes increasingly stiff, partly because

movement is painful and partly because movement is

272

(a)

limited by adhesion formation, muscle spasm and bone destruction. In the spine,

swelling is not visible until a considerable quantity of tuberculous pus has

collected and stiffness may be too slight to be noticed by the patient; thus a mild

ache may be the only symptom of a potentially crippling disease. A kyphos

appears late in the disease.

Systemically, the patient feels unwell, listless and febrile the latter especially

at night, when night sweats max occur, but the local disease can be quite

advanced before systemic symptoms occur.Physical signs. If the joint is superficial, the synovial thickening and effusion

may be visible. The muscles acting on the joint are markedly wasted The joint is

held in its position of ease (Table 17.1)

On palpation, the synovial thickening and effusion can again be made out and the

joint will be found to be moderately tender. The skin overlying the joint, even if

abscess formation has occurred, is not red and is only slightly warm, a feature

which is characteristic of tuberculous inflammation and abscess formation, so that

such abscesses are known as cold abscesses. Active and passive movement of the

joint will be limited and painful.

In the spine, the only physical signs of the disease in its early stages are

tenderness on percussion of the spinous processes of the involved vertebrae and

minimal limitation of movement. Later, a kyphos may be seen (Fig. 17.5) and

abscesses may be visible in the groin or posteriorly in the triangle of Petit. A

kyphos in the lumbar spine may be masked by the normal lumbar lordosis.

Special investigations.Haematology and immunology. The ESR and white cell

count are usually raised, the latter with a lymphoLytosis, but normal values should

not be taken as refuting the diagnosis. The Mantoux test is positive sometimes

violently so. The haemoglobin concentration should be measured since anaemia is

common and requires correction.Radiology. The early radiological signs are not dramatic: the bone adjacent to the

joint is a little less dense than normal and it may be possible to make out a soft-

tissue swelling. As the disease advances, the joint space or disc space narrows and

bone destruction becomes visible as an area of osteolysis. Thus in the spine, a

characteristic appearance now develops: the disc space narrows, and lyric lesions,

typically anterior, appear in the bones of the adjacent vertebral bodies. Further


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bony destruction is accompanied by abscess formation so that diseased bone is

seen to lie in and around a soft-tissue shadow containing loose fragments of bone

and calcified soft tissue (Figs 17.4b and 17.6). At this stage, deformity can be

radiologically obvious (Fig. 17.4a).

A chest radiograph should always be taken and may reveal active tuberculosis.

Jean Louis Petit, 16747750 Parisian surgeon

Fig. 17.6 Radiological appearances in active tuberculosis of the hip joint in a child.

Histology. Early accurate diagnosis is imperative, since tuberculous arthritis can

be cured (to leave the patient with no loss of function) provided it is adequately

treated before bone and cartilage are destroyed. Early in the disease the clinical,

haematological, immune and radiological features are not diagnostic, so

histological examination of biopsy material (revealing acid-fast bacilli and typicaltubercles) is essential. Material for biopsy purposes may be obtained in the

following ways.

Removal of lymph nodes. An involved node draining the diseased joint may be

removed. The disadvantage of this method is that a negative result does not esdude

the presence of the disease.

Art hrotonzy and biopsy of the synovial membrane. This method allows the

appearance of the joint to be noted and provides certain histological diagnosis. The

disadvantage is the risk cit sinus formation through the operative wound. Provided

the operation is carried Out under antibiotic cover (see below) this risk is

negligible. This is therefore the method of choice. Where available, the arthroscope

can be used rather than resorting to a full arthrotomy.

Needle biopsy of radiologically involved tissue. This is the method of choice in

the spine because direct surgical access may be difficult.

Bacteriology. Joint aspirate, biopsy material, sputum and urine should be cultured

for tubercle bacilli. A positive culture may take some weeks to obtain. A diagnosis

should have been made by this time on the basis of the histology, and treatment

started Bacteriology is therefore confirmatory, but is necessary to assess thesensitivity of the organism to the various antituberculous agents.

Differential diagnosis. Tuberculous arthritis may be confused with rheumatoid

arthritis in a single joint, infective arthritis, and haemarthroses occurring in

haemophiia. In the spine, the differential diagnosis is from osteomyelitis due to


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other organisms (especially staphylococcus and typhoid bacillus), ankylosing

spondylitis, back pain due to disc prolapse and degeneration, and neoplasm.

Treatment.Antibiotics. Immediately the diagnosis is made, the guidelines

avocated in Chapters 6 and 7 should be followed for at least 12 months (isoniazid

plus rifampictn with or without ethambutollstreptomycin). If the diagnosis depends

upon synovial biopsy, antibiotics are started immediately postoperatively, without

awaiting the histological result.

273

Im,nobilisation. The diseased joint is irn.mobilised in the position of function

(Table 17.1) until local symptoms have settled. In the case of the spine,

immobilisation requires the use of a collar for the cervical spine lesion, or bed rest

until local symptoms have subsided. In countries where hospitalisation may be

difficult, tuberculosis of the lumbar spine has recently been treated by antibioticsalone, the patient remaining ambulant throughout the period of treatment.

General management. The general health of the patient should of course be

improved as far as possible by providing an adequate normal diet and by giving an

iron supplement or even blood transfusion if there is significant anaemia. Should

there be coincidental pulmonary tuberculosis with tubercle bacilli in the sputum, it

will of course be necessary to isolate the patient until this aspect of the disease is

brought under control. Sanatoria, sunshine and special diets are not necessary.

Surgery. Surgery is not required at the aynovial stage of the disease since, in this

case, the disease can be arrested by antibiotics alone. If, however, the synovial

membrane is very markedly inflamed and thickened, synovectomy and joint toilet

may be helpful.

If abscess formation has occurred, the abscess is incised and thoroughly evacuated

3 or 4 weeks after the commencement of antibiotic treatment. When the abscess

has been evacuated, the originally articulating bones terminate in the abscess

cavity and the joint will never regain its normal function: it is stiff, movement is

painful, and weight bearing in the spine and legs is particularly painful or

impossible. Some form of arthrodesis is required in order to provide the patient

with a painless stable, although stiff, joint. Before antibiotics became available,arthrodesis of a tuberculous joint was carried out avoiding. if possible, the infected

tissue (Fig. 17.7). Such operations (extraarticular arthrodeses) are technically

difficult. Since the advent of antibiotics, the bone ends can be brought into

apposition across the evacuated abscess cavity and sound bony fusion can

commonly be obtained in this way.

In the spine, exactly the same surgical principles apply. The disease is rarely


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diagnosed before bone involvement has taken place and some form of arthrodesis

may be required. If no significant pus formation has occurred when antibiotics are

given, it is usually possible to sterilise the lesion in the vertebral bodies so that

healing results in an anterior interbods fusion; if pus has formed, this needs

Fig. 17.7 Brittains ischiofemoral, extra-articular arthrodesis of the hip (see text).

to be evacuated. Fusion can be assisted, when the lesions have been sterilised, by

the use of bone grafts. If there is likely to be considerable spinal deformity

(particularly in the cervical spine), surgical excision of the diseased tissue and a

bone graft may be necessary.

Occasionally, the disease leaves a joint which is replaced by short, firm fibrous

tissue (a sound fibrous ankvlosis). Tissue of this kind may be sufficiently stable

to allow the joint to function as if it were arthrodesed, especially in the nonweight-

bearing upper limb, so that no surgical arthrodesis may be necessary. A fall ortwist can loosen a fibrous ankvlosis.

Prognosis. The prognosis for this disease is now excellent. Death either from the

tuberculous process itself or from secondary amvloidosis is now rare.

Disability of any kind can often he prevented by early, adequate antibiotic

treatment combined with appropriate immobilisation. At the worst, the patient may

spend some months in hospital and, when finally cured of the tuberculous process,

have a permanently stiffened joint.

TUBERCULOUS TENOSYNOVITIS

This may take two forms:

the endothelial lining of the sheath is replaced by oedematous granulation tissue

containing miliaxy tuberdes. ve~ little free fluid is present. A soft, elastic swelling

appears and if the disease progresses, pus may form and track into neighbouring

sheaths or joints;

an effusion occurs in the tendon sheaths and melon-aced bodies are usuallypresent in large numbers, so that a soft, coarse crepitus is detected on pressing fluid

from one part of the sheath to another. Melon-seed bodies resemble grains of

boiled sago. They are composed of collections of fibrin. cellular debris and

occasional

o 2 3 4cm


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FIg. 17.8 Melon-seed bodies from tuberculous synovitis at the wrist.

Fig. 17.9 A compound palmar ganolion (tuberculous flexor synovitis at the wrist).

The swelling in the palm communicaiet with the swelling above the wrist, and

crosadluctustiun can be demonstrated sometzntes.

2>i

H,l. Britt~i,t l9O4-~54. Orthipadi: su~yc.m. Norf~1k arid Norwich

tubercle bacilli (Fig. 17.8). The term compound palmar ganglion is applied to this

condition when it occurs in connection with the flexor tendons of the fingers. A

soft, painless swelling appears (Fig. 17.9), and fluctuation may be transmitted

above and below the anterior carps! ligament.

As with all forms of tuberculous disease of bone, joint or tendon, obvious wasting

of adjacent musdes is present. Treatment consists of genera] measures, the use of

antibiotics and the application of an appropriate plaster cast to immobilise theinvolved tendon sheath. If the condition progresses, careful dissection and removal

of the tendon sheath is indicated. This is a technically demanding procedure.

FURTHER READING

Galasko, C.S.B. (1989) The management of bone and joint infections.British

Journal of Hospital Medicine,

42, 3244.

Goldschmidt, RB. and Hoffmann, E.B. (1991) Osteomyelitis and septic arthritis in

children. Current Orthopaedics, 5, 24855.

Hughes, 5FF. and Fitzgerald, R.H. (1986)Musculoskeletal Infections, Year Book

Publishers, Chicago.

Ch17 Diseases of Bones and Joints_ Inf

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