Septic Arthritis Flashcards
What is septic arthritis?
Acute joint inflammation resulting from intra-articular infection (infection of cartilage + synovial fluid)
Can destroy a joint in <24h
Usually affects knee
Describe the aetiology of septic arthritis
May be idiopathic
In most cases there is systemic infection allowing for haematogenous spread but can also be secondary to direct inoculation of organisms into the joint
List 9 risk factors for septic arthritis
Recent orthopaedic procedures Osteomyelitis DM RA Prosthetic joints Immunosuppression Alcoholism IV drug use 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
Joint redness, swelling + loss 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 urgently in suspected septic arthritis?
Joint Aspiration: to start on Abx ASAP
URGENT GRAM STAIN
Aspirate: grossly purulent- low viscosity, turbid, yellow
Synovial WCC: HIGH
Send synovial fluid for MC+S: exclude crystal arthritis
PCR may be used if a viral cause is suspected
Performed under USS guidance if hip sepsis is suspected
What investigations are performed in septic arthritis?
Bloods Blood cultures: MC+S Viral serology X-Ray MRI: to detect osteomyelitis
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?
All ages
Staphylococcus aureus
TB (suspected in immunocompromised)
< 4 yrs Strep. pneumoniae Strep. pyogenes Neisseria meningitidis Gram-negative rods
16-40 yrs
Neisseria gonorrhoeae
What are the common causative viruses of septic arthritis?
Rubella Mumps Hepatitis B Parvovirus B19 Fungi Candida
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
