Septic Arthritis Flashcards
What is septic arthritis?
Acute joint inflammation resulting from intra-articular infection (cartilage + synovial fluid)
Can destroy a joint in <24h
Usually affects knee
Describe the aetiology of septic arthritis
May be idiopathic
Usually systemic infection allowing for haematogenous spread but can also be 2nd to direct inoculation of organisms into joint
9 RFs for septic arthritis
Recent orthopaedic procedures Osteomyelitis DM RA Prosthetic joints Immunosuppression Alcoholism IVDU Hx of cutaneous ulcers
Describe the epidemiology of septic arthritis
Most common in CHILDREN + ELDERLY
List 3 symptoms of septic arthritis
Sudden onset
Excruciating joint pain
Lloss of joint function
List 4 signs of septic arthritis
Painful, hot, swollen, immobile joint
Erythema
Severe pain prevents passive movement
Pyrexia
What investigations are performed in septic arthritis?
Joint aspiration
Blood cultures
Bloods: CBC, CRP, ESR
X-ray
Describe the onset and distribution of septic arthritis
Sudden onset, usually monoarthropathy (1 large joint)
May cause polyarthropathy in immunosuppressed
TB arthritis develops more slowly + is more chronic
What are the common causative bacteria of septic arthritis in all age groups?
Staphylococcus aureus
TB (suspected in immunocompromised)
What are the common non-bacterial causes of septic arthritis?
Rubella Mumps Hepatitis B Parvovirus B19 Fungi: Candida
What classical triad is seen in patients with septic arthritis?
Fever
Joint pain
Restricted range of motion
4 common causative bacteria of septic arthritis in <4s
Strep. pneumoniae
Strep. pyogenes
Neisseria meningitidis
Gram-negative rods
Common causative bacteria of septic arthritis in 16-40s
Neisseria gonorrhoeae
Describe synovial fluid analysis findings in septic arthritis
Grossly purulent- low viscosity, turbid, yellow HIGH WCC: Neutrophil dominance Lower glucose than blood MC+S for sensitivity Gram stain
What is an absolute contraindication to joint aspiration in suspected septic arthritis?
Infection of skin/ cellulitis surrounding affected joint
Risks introducing pathogen into joint
