Acute and chronic osteomyelitis Dr Alihussein Kassam

DR ALIHUSSEIN I KASSAMMNAZI MMOJA HOSPITAL

INTERN DOCTOR

ACUTE AND CHRONIC OSTEOMYELITIS

3 May 2023Dr Alihussein Kassam

DEFINITION

Inflammation of the bone caused by an infecting organism


Introduction The key to successful management

is early diagnosis and appropriate surgical and antimicrobial treatment.

A multi disciplinary approach is required, involving an orthopaedic surgeon, an infectious disease specialist, and a plastic surgeon in complex cases with significant soft tissue loss.


Classification 1) The duration - acute, subacute and

chronic

2) Mechanism of infection – exogenous or hematogenous

3) The type of host response to the infection- pyogenic or non pyogenic


Acute hematogenous osteomyelitisBimodal distribution- younger than 2

years, and 8-12 years



Acute hematogenous osteomyelitis microbial patternStaphylococcus aureus most common

in older children and adultsGram negative bacteria- increasing

trend- vertebralPseudomonas most common in

intravenous drug abusersSalmonella in sicke cellFungal infections in chronically ill

patients on long term intravenous therapy.


Acute hematogenous osteomyelitismicrobial patternInfants- staph aureus most common but

group B streptococcus and gram negative coliforms

Prematures staph aureus andgram negative organisms

Hemophilus influenzae primarily in children 6 months to 4 years old, incidence decreased dramatically by immunizations


Acute hematogenous osteomyelitisdiagnosisHistory and physical examination

Fever and malaisePain and local tendernessSweliingCompartment syndrome in children


Acute hematogenous osteomyelitisdiagnosisLaboratory tests

White blood cell countErythrocyte sedimentation rateC-reactive protein

checked very 2- 3 days post treatment initiation

Aspiration for suspected abscess


Acute hematogenous osteomyelitisdiagnosis

Plain radiographs

Technetium-99m bone scan +/- MRI


Radiographs Soft tissue swelling

Periosteal reaction

Bony destruction (10-12 days)


Bone scan

Can confirm diagnosis

24-48 hrs after onset


Acute hematogenous osteomyelitisTreatmentSurgery and antibiotic treatment are

complementary, in some cases antibiotics alone may cure the disease.

Choice of antibiotics is based on the highest bacteriocidal activity, the least toxicity and the lowest cost


Acute hematogenous osteomyelitisTreatmentNade’s 5 principles of treatment

1. An appropriate antibiotic is effective before pus formation

2. Antibiotics do not sterilize avascular tissues or abscesses and such areas require surgical removal


Acute hematogenous osteomyelitisTreatment- nades principles

3. If such removal is effective, antibiotics should prevent their reformation and primary wound closure should be safe

4. Surgery should not damage already ischaemic bone and soft tissue

5. Antibiotics should be continued after surgery


Acute hematogenous osteomyelitisTreatment

The two main indications for surgery in acute hematogenous osteomyelitis are:1. The presence of an abscess

requiring drainage2. Failure of the patient to improve

despite appropriate intravenous antibiotic treatment


Acute hematogenous osteomyelitisTreatment- surgeryThe objective of surgery is to drain any

abscess cavity and remove all non viable or necrotic tissue

Subperiosteal abscess in an infant-several small holes drilled through the cortex into the medullary canal

If intramedullary pus is found, a small window of bone is removed

Skin is closed loosely over drains and the limb splinted


Acute hematogenous osteomyelitisTreatment

Generally a 6 week course of intravenous antibiotics is given

Orthopedic and infectious disease followup is continued for at least 1 year


CHRONIC OSTEOMYELITISHallmark is infected dead bone within

a compromised soft tissue envelope

The infected foci within the bone are surrounded by sclerotic, relatively avascular bone covered by a thickened periosteum and scarred muscle and subcutaneous tissue


Classification of COM


Anatomical classification


Classification of COM


Diagnosis COM

Based on Clinical laboratory and imaging studies


Clinical evaluation COM

Skin and soft tissue integrityTenderness Bone stabilityNeurovascular status of limbPresence of sinus


Laboratory COM Erythrocyte sedimentation rateC reactive proteinWBC count only elevated in 35%Biopsy for histological and

microbiological evaluationStaphyloccocus speciesAnaerobes and gram negative bacilli


Imaging studies in COMPlain X rays

Cortical destructionPeriosteal reactionSequestra Sinography


Sinography


COM Imaging

CT ScanIdentifying sequestraDefinition of cortical bone and surrounding soft tissues


COM ImagingMRI

Shows margins of bone and soft tissue oedema

Evaluate recurrence of infection after 1 year

Rim sign- well defined rim of high signal intensity surrounding the focus of active disease

Sinus tracks and cellulitis3 May 2023Dr Alihussein Kassam

Treatment of COMSurgical treatment mainstay

SequestrectomyResection of scarred and infected bone and debridement


Surgical treatment of COMAdequate debridement leaves a dead

space that needs to be managed to avoid recurrence, or bony instabilitySkin grafts,Muscle and myocutaneous flapsFree bone transferPapineau techniqueHyperbaric oxygen therapyVacuum dressing


Treatment of COMAntibiotic duration is controversial

6 week is the traditional duration1 week IV, 6 weeks of oral therapyAntibiotic polymethyl methacrylate

(PMMA) beads as a temporary filler of dead space

Biodegradable antibiotic delivery system


Resection or excision for COM

Resection of a segment of affected bone may be necessary to control infection

With techniques of bone and soft tissue transport, massive resections can be performed and reconstructed without significant disability.


Resection or excision for COM


Amputation for osteomyelitisAmputation indications include

Arterial insufficiencyMajor nerve paralysisNon functional limb-stiffness,

contractureMalignant change

Prevalence of maliganacy arising from COM reported as 0.2 to 1.6% of cases.

Most are squamous cell carcinoma, also reticulum cell carcinoma,fibrosarcoma


References Canale Terry and Beaty James (2007) Campbell’s

Operative Orthopaedics, Philadelphia, Mosby Ben Mbonye-Girasi (1981) Mode of Presentation and

End results of Management of Haematogenous Osteomyelitis at the Orthopaedic Unit Kenyatta National Hospital over a Five Year Period. Nairobi : unpublished masters in medicine project, School of Medicine, University of Nairobi

Issac K Ngetich (2002) A Study of Haematogenous Osteomyelitis in Children in Kenyatta National Hospital Kenya. Nairobi : unpublished masters in medicine project, School of Medicine, University of Nairobi

Lewis R P, Sutter V L and Finegold S M (1978) Bone Infections Involving Anaerobic Bacteria. Baltimore pub med PMID 207946


Health & Medicine

Acute and chronic osteomyelitis Dr Alihussein Kassam