Bone and Joint Infections Flashcards
Is septic arthritis usually mono or poly - articular?
Monoarticular 90% of the time
What are the signs/symptoms of acute septic arthritis?
Fever (>39), restricted ROM, swelling and inflammation
What are the signs/symptoms of chronic septic arthritis?
Restricted ROM, swelling, inflammation, but no fever (not systemic)
What type of bacteria are Streptococcus pyogenes, pneumoniae group B and Staphylococcus Aureus?
Gram positive cocci bacteria
What type of bacteria is Neisseria Gonorrhoea?
Gram negative cocci
What kind of bacteria is Haemophilus Infleunza?
Gram negative bacilli
What is the most common cause of septic arthritis?
Staphylococcus aureus and Neisseria Gonorrhoea (16-50 year olds)
What area is most commonly affected by septic arthritis?
The knee, but can occur at the hip, ankle and elbow
What are the likely lab findings for someone with septic arthritis?
Elevated ESR/CRP, neutrophilia and synovial fluid may be purulent with reduced glucose levels
How would infiltration of TB (mycobacterial infection) in a joint present on x-ray?
Joint space narrowing, effusions, erosions and cyst formation
How may you distinguish between rheumatoid arthritis and septic arthritis?
RA is almost always bilateral, whereas septic arthritis is usually monoarticular
How is septic arthritis treated?
Drainage and antibiotics
What is reactive (Reiter’s) arthritis?
Reactive/post-infectious arthritis
The presence of which HLA receptor is a risk factor for reactive arthritis?
HLA-B27
What may cause reactive arthritis?
STI (chlamydia trachamatis), enteritis (salmonella campylobacter) or mzycobacter (TB)
How does reactive arthritis usually present?
These are extra-articular symptoms
What is osteomyelitis?
Infection of the bone (marrow) that mainly occurs due to haematogenous spread where there is thereafter a contiguous spread from an infected focus.
What are risk factors for osteomyelitis?
o Impairment of immune surveillance e.g. malnutrition, extremes of age
o Impairment of local vascular supply e.g. diabetes mellitus, venous stasis, radiation fibrosis or sickle cell disease
What is a Brodies’ abscess and when may it be seen?
Oval-shaped lesion that is surrounded by a thick, reactive hardening
What kind of bacteria can flucloxacillin kill?
Gram positive bacteria e.g. staphylococcus and streptococcus
What are the signs and symptoms of osteomyelitis?
Long bone: abrupt onset of fever, decreased limb movement and joint effusion
Chronic vertebral infection: insidious onset over 1-3 months
Non-specific pain presents
What may the lab results show for osteomyelitis?
Elevated ESR and neutrophils,
How is osteomyelitis treated?
Antibiotics, surgical debridement (remove dead bone) and bone reconstruct if necessary
What are the risk factors for infection due to a prosthesis?
Prior surgery at site of prosthesis, RA, corticosteroid therapy, diabetes, obesity, malnutrition, old age
How may infections from prostheses be avoided?
Eliminate infected foci (e.g. bad teeth), use peri-operative antibiotics, use laminar flow theatre ventilation, surgical team wear body suits, prophylaxis for subsequent interventions
How may infections from prostheses be seen on x-rays?
There may be lucencies at the bone-cement interface, with changes in component position, cement fractures, periosteal reactions or gas in the joint
How may infections from prostheses be treated?
Keep/replace prosthesis, resect the damage tissue or long-term antibiotics
