Bone and Soft Tissue Infection Flashcards
What are the risk factors for acute osteomyelitis?
Diabetes Rheumatoid arthritis Immune compromise Long term steroid treatment Sickle cell
What are the source of infection of acute osteomyelitis?
Haematogenous spread Local spread from contigous site of infection Secondary to vascular insufficiency Infected umbilical cord (infants) Boils Tonsilitis Skin abrasions UTI Arterial line
What are the common organisms that cause acute osteomyelitis?
Staph aureus Strep pyogenes Haemophilus influenzae Mycobacteroum tuberculosis Brucella Group B streptococci E coli
What is the pathology of acute osteomyelitis?
Starts at metaphysis Vascular stasis Acute inflammation, increased pressure Suppuration Release of pressure Necrosis of bone New bone formation
What are the clinical features of acute osteomyelitis in infants?
Failure to thrive Drowsy or irritable Metaphyseal tenderness and swelling Decreased range of movement Positional change Commonest around knee
What are the clinical feature of acute osteomyelitis in children?
Severe pain Reluctant to move, not weight bearing May be tender fever and tachycardia Malaise Toxaemia
What are the clinical features of acute osteomyelitis in adults?
Primary OM commonly seen in thoracolumbar spine
Back ache
History of UTI or urological procedure
Elderly, diabetic, immunocompromised
What investigations should be used to make a diagnosis for acute osteomyelitis?
History and examination FBC and diff WBC ESR, CRP Blood cultures x3 U&Es X ray USS Aspiration Isotope bone scan Labelles white cell scan MRI
What is the differential diagnosis of acute osteomyelitis?
Acute septic arthritis Trauma Acute inflammatory arthritis Transient synovitis Soft tissue infection
What is the treatment of acute osteomyelitis?
Rest and splintage
Antibiotics
Supportive treatment for pain and dehydration
Surgery
What are the indications for surgery in acute osteomyelitis?
Aspiration of pus for diagnosis and culture
Abscess drainage
Debridement of dead/infected/ contaminated tissue
What are the complications of acute osteomyelitis?
Septicaemia, death Metastatic infection Pathological fracture Septic arthritis Altered bone growth Chronic osteomyelitis
What is subacute osteomyelitis?
Increased host resistance/ lowered bacterial virulence or antibiotic usage
What are the clinical features of subacute osteomyelitis?
Long history Pain Limp Local swelling/warmth occasionally Tenderness
What are the clinical features of Brodie’s abscess?
Older children
Painful limp, no systemic features
Radiographic lucency in long bone metaphysis
What is the treatment for subacute osteomyelitis?
Prolonged course of antibiotics
Surgery- curettage
What is the pathology of chronic osteomyelitis?
Cavities, possibly sinuses
Dead bone (retained sequestra)
Involucrum
What is the treatment of chronic osteomyelitis?
Long term antibiotics Eradicate bone infection- surgically Treat soft tissue problems Reconstruction Amputation
What are the complications of chronic osteomyelitis?
Chronically discharging sinus and flare up Ongoing infection Pathological fracture Growth disturbances and deformities Squamous cell carcinoma
What is the route of infection of acute septic arthritis?
Direct invasion
Eruption of bone abscess
Haematogenous
What are the common organisms that cause acute septic arthritis?
Staph aureus
Haemophilus influenzae
Strep pyogenes
E coli
What is the pathology of acute septic arthritis?
Acute synovitis with purulent joint effusion
Articular cartilage attacked by bacterial toxin and cellular enzyme
Complete destruction of the articular cartilage
What are the clinical features of acute septic arthritis in a neonate?
Irritability
Resistant to movement
Ill
What are the clinical features of acute septic arthritis in a child?
Acute pain in a single large joint
Reluctant to move the joint
Increased temperature and pulse
Increase tenderness
What are the clinical features of acute septic arthritis in an adult?
Often involves superficial joint
What investigations should be made for acute septic arthritis?
FBC, WBC, CRP, ESR, blood cultures
X ray
USS
Aspiration
What is the differential diagnosis of acute septic arthritis?
Acute osteomyelitis Trauma Irritable joint Haemophilia Rheumatic fever Gout Gaucher's disease
What is the treatment for acute septic arthritis?
General supportive measures
Antibiotics (3-4 weeks)
Surgical drainage and lavage
What are the clinical features of tuberculosis in bones?
Insidious onset and general ill health Contact with TB Pain, esp at night, swelling, loss of weight Low grade pyrexia Joint swelling Decrease range of movement Ankylosis Deformity
What is the pathology of TB with regards to bone?
Primary complex (in the lung or gut)
Secondary spread
Tuberculous granuloma
What signs on examination and investigation would help make a diagnosis of TB?
Long history Involvement of single joint Marked thickening of the synovium Marked muscle wasting Periarticular osteoporosis
What investigation should be used when making a diagnosis of TB?
FBC, ESR Mantoux test Sputum/ urine culture XRAY Joint aspiration and biopsy
What is the differential diagnosis of TB?
Transient synovitis
Monoarticular rheumatoid arthritis
Haemorrhagic arthritis
Pyogenic arthritis
What is the treatment for TB?
Initially rifampicin, ethambutol and isoniazid (8 weeks)
Then rifampicin and isoniazid (6-12 months)
Rest and splintage
