1. Osteomyelitis

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Chronic Osteomyelitis

Severe, persistent,and incapacitatinginfectionof bone and bone marrow ofmore than 6 weeksduration characterised

by recurrent attacks of inflammation withsinuses discharging.

Used to be common sequel to acutehaematogenous osteomyelitis.

Nowadays, frequently follows an openfracture or operation.


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Common organisms

Usual causative organisms:

S. aureus

E. coli

S. pyogenes

Proteus

Pseudomonas

S. epidermidis(commonest in the presence of

foreign implant)


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Pathology

Acute OM commonly leads to chronic OMbecause of > 1 of these reasons:

1) delayed & inadequate tx:

causes spreads of pus within the medullary

cavity & subperiosteally

death of a part of the bone

(sequestrum formation)


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2) type & virulence of organisms

body defense mechanism may not be able tocontrol

3) decreased host resistance

malnutrition compromises bodys defencemechanisms

4) iatrogenic

joints replacements & internal fixation offracture.


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Chracterised by

formation of a

sequestrum, involucrumand discharge of pus.


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Clinical Features

Chronic discharging sinus Commonest presenting symptoms

Onset of sinus may be traced back to an episode of acute OMduring childhood

Often sinuses heal for short periods, only to reappear with each

acute exacerbation Sero-purulentthick pus

H/o extrusion of small bone fragments from the sinuses

Pain Usually minimal but may become aggravated during acute

exacerbations Swelling, redness

Malaise, fatigue

Non-healing ulcer, deformed/non-united bone

Fever (only during acute exacerbation)


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Physical Examination

Chronic discharging sinus

Fixed to underlying bone

Sprouting granulation tissue at its opening, indicating

a sequestrum within the bone Sequestrum may be visible at the mouth of the sinus

itself

Sinus may be surrounded by healed puckered scars

(previous healed sinuses)


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Investigations

Blood

ESR:

During acute flares: CRP,WCC may be

Antistaphylococcal antibody titres may be elevated

Pus culture

Organisms cultured from discharging sinuses should

be tested repeatedly for antibiotic sensitivity

With time, they often change their characteristics and

become resistant to treatment


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X-ray:

- Bone resorption - thickening, irregular &sclerosis of the cortices (surrounding bone).

- Sequestra (dense fragments)

- Bone cavity - an area of rarefaction surroundedby sclerosis.

- Involucrum & cloacae.

Radioisotope scintigraphy (bone scan):

- sensitive but not specific.

- increased uptake at metaphysis.


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Treatment

Principal of treatment: mainlysurgical

Antibiotics:

During acute exacerbations

During post-operative period

The aim of surgical intervention is

Removal of dead bone

Elimination of dead space Removal of infected granulation tissue and

sinuses


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Operative procedures

1) Sequestrectomy

Removal of sequestrum

If it lies within the medullary cavity, a window is made

in the overlying involucrum & the sequestrumremoved

Must have adequate involucrum formation before

performing sequestrectomy


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2) Saucerization

A bone cavity is a non-collapsing cavity so

that there is always some pent-up pus inside

it.

This is responsible for the persistence of

infection

The cavity is converted into a saucer byremoving its wall. This allows free drainage of

the infected material.


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3) Curettage

The wall of the cavity, lined by infected granulation

tissue, is curettaged until the underlying normal-

looking bone is seen.

The cavity is sometimes filled with Gentamicin

impregnated beads to fill up the dead space.

4) Excision of an infected bone

Affected bone can be excised en-bloc without

compromising the functions of the limb

Close the gap by Ilizarovs method of transporting a

viable segment of the bone from adjacent part.

5) Amputation

May be preferred in a case with a long-standing

discharging sinus, especially if the sinus undergoes

malignant change.


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Complications

Acute exacerbationor flare up

Occurs commonly

Subsides with a period of rest and antibiotics

Growth abnormalities

Shorteningwhen growth plate is damaged

Lengtheningincreased vascularity of the growthplate d/t nearby osteomyelitis

Deformity- part of the growth plate is damaged & the

remaining keeps growing


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A pathological fracture

May occur through weakened area of the bone

Conservative treatment

Joint stiffness

May occur because of scarring of the soft tissues or asecondary infection of the joint

Sinus tract malignancy

A rare complication

It occurs many years after the onset of osteomyelitis

Squamous cell carcinoma

Need amputation

Amyloidosis


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Documents

1. Osteomyelitis