Bone and Soft Tissue Infection Flashcards
Are adults or children more susceptible to acute osteomyelitis?
Children
Are boys or girls more likely to get acute osteomyelitis?
Boys
What history can increase the chances of somone getting acute osteomyelitis?
History of trauma Diabetes Rheumatoid arthritis Immunocompromised Long term steroid treatment Sickle cell
What can cause osteomyelitis?
Haematogenous spread
Local spread from contiguous site of infection - trauma, bone surgery, joint replacement
Secondary to vascular insufficiency
What can be a source of infection in infants?
Infected umbilical cord
What are sources of infection in children?
Boils
Tonsilitis
Skin abrasions
What are sources of infection in adults?
UTI
Arterial line
What is the most common infecting organism in acute osteomyelitis?
Staph aureus
What is likely to be an infective organism in acute osteomyelitis in patients with diabetic foot and pressure sores?
Mixed infection with anaerobes
What is the likely causative organism in acute osteomyelitis in a patient with sickle cell disease?
Salmonella species
What are common places to be affected by acute osteomyelitis?
Distal femur Proximal tibia Proximal humerus Hip joint Elbow - radial head
What is the progression of acute osteomyelitis?
Starts at metaphysis Vascular stasis Acute inflammation - increased pressure Formation of pus Release of pressure Necrosis of bone New bone formation Resolution or not? May lead to chronic
What are clinical signs of acute osteomyelitis in infants?
May be very ill Failure to thrive Possibly drowsy or irritable Metaphyseal tenderness and swelling Decrease range of movement Positional change
What are clinical features of acute osteomyelitis in children?
Severe pain Reluctant to move - not weight bearing Fever and tachycardia Malaise Toxaemia
What are clinical features of acute osteomyelitis in adults?
Primary infection seen commonly in thoracolumbar spine
Backache
History of UTI
Secondary is much more common
How is acute osteomyelitis diagnosed?
History and clinical examination FBC + WBC ESR,CRP 3xblood cultures U&Es X-Ray/ultrasound Aspiration Isotope bone scan
What are differential diagnoses for acute osteomyelitis?
Acute septic arthritis Acute inflammatory arthritis Trauma Transient synovitis Soft tissue infection
How is acute osteomyelitis treated?
Supportive treatment for pain and dehydration
Rest and splintage
Antibiotics 4-6 weeks
What can cause antibiotics to fail to treat something?
Drug resistance Bacterial persistence Poor host defences Poor drug absorption Drug inactivation by host flora Poor tissue penetration
What are indications for surgery in acute osteomyelitis?
Aspiration of pus for diagnosis
Abscess drainage
Debridement of dead/infected tissue
Refractory to non operative treatment
What are complications of acute osteomyelitis?
Septicaemia/death Metastatic infection Pathological fracture Septic arthritis Altered bone growth Chronic osteomyelitis
What can cause chronic osteomyelitis other than following an acute case?
Following an operation
Diabetic
Immunosuppressed
Elderly
What are the most common causative organisms of chronic osteomyelitis?
Staph aureus
E Coli
Strep pyogenes
What are complications of chronic osteomyelitis?
Chronically discharging sinus and flare-ups
Pathological fracture
Growth disturbance and deformities
Squamous cell carcinoma
How is chronic osteomyelitis treated?
Long-term antibiotics Eradicate bone infection Treat soft tissue problems Correct deformities Reconstruction Amputation?
What are routes of infection in acute septic arthritis?
Haematogenous
Eruption of bone abscess
Direct invasion
What are common causative organisms of acute septic arthritis?
Staph aureus
Haemophilus influenzae
Strep pyogenes
E coli
What is the progression of acute septic arthritis?
Acute synovitis with purulent effusion
Articular cartilage attacked by bacterial toxin and cellular enzyme
Complete destruction of the articular cartilage
What are features of acute septic arthritis in neonates?
Irritability
Resistant to movement
ill
What are features of acute septic arthritis in children and adults?
Acute pain in a single large joint
Reluctant to move the joint
Increase temp and pulse
Increase tenderness
What investigations are done into acute septic arthritis?
FBC, WBC, CRP, etc
Blood cultures
X-ray/ultrasound
Aspiration
How is acute septic arthritis treated?
General supportive measures
Antibiotics 3-4weeks
Surgical drainage
What is sequestrum?
Necrosis of bone
What is involucrum?
Growth of new bone layer outside of existing bone
What are the classifications of tuberculosis in bone and joint?
Extra-articular (epiphyseal)
Intra-articular (large joints)
Vertebral body
What are clinical features of Tuberculosis?
Insidious onset and general ill health Contact with TB Pain, swelling, weight loss Low grade pyrexia Joint swelling Decrease range of movement Ankylosis Deformity
What are features of spinal tuberculosis?
Little pain
Presents with abscess or kyphosis
How is tuberculosis diagnosed?
Long history Involvement of a single joint Marked thickening of the synovium Marked muscle wasting Periarticular osteoperosis
What investigations can be done into TB?
FBC, ESR Mantoux test Sputum/urine culture Xray Joint aspiration and biopsy
What would you expect to see in an Xray with TB?
Soft tissue swelling
Periarticular osteopaenia
Articular space narrowing
What is Mantoux test?
Intradermal injection of tuberculin and immune response is measured 48-72 hours later
What are differential diagnoses for TB?
Transient synovitis Monoarticular rheumatoid arthritis Haemorrhagic arthritis Pyogenic arthritis Tumour
How is TB treated?
Chemotherapy
Rest and splintage
Operative drainage rarely necessary
What drugs are used for chemotherapy of TB?
For 8 weeks : Rifampicin Isoniazid Etjambutol Then Rifampicin and isoniazid for 6-12 months
