Septic Arthritis Flashcards
Define septic arthritis
Refers to an infection of one or more joints caused by pathogenic inoculation of microbes
What two ways can the bacteria spread into the joint causing septic arthritis
Direct inoculation
OR
Via haematogenous spread
Septic arthritis is a medical emergency.
What can occur if treatment is delayed
Can result in permanent joint damage and systemic sepsis
What is the most common causative pathogen causing septic arthritis
Staphylococcus Aureus
What joints are affected in septic arthritis
Any joint can be affected but large joints (e.g. hip and knee) are most common
Name the two categories of septic arthritis
Native joint infection
Prosthetic joint infection
Native joint infection is a type of septic arthritis.
How is it usually treated
Infection affecting a native joint
Management typically requires joint drainage (where appropriate) and antimicrobial therapy.
Prosthetic joint infection is a type of septic arthritis.
How is it usually treated
Serious complication of prosthetic joint replacement.
Surgical intervention in addition to antimicrobial therapy is commonly required.
Name some of the risk factors for septic arthritis
Extremes of age (children and elderly)
Prosthetic joint
Underlying joint disease
Immunodeficiency/Immunocompromised
IVDU
Which causative bacteria is most common in IVDU
[septic arthritis]
Pseudomonas aeruginosa
Which causative bacteria is most common in young, sexually active individuals
[septic arthritis]
Neisseria gonorrhoeae
Describe the pathogenesis of septic arthritis
Arises when pathogens (most commonly bacteria) enter the synovium
Pathogens can spread to the synovium either by haematogenous spread or by direct inoculation
Haematogenous spread is the most common mechanism. It is the result of a bacterium located in the bloodstream seeding into the joint
Direct inoculation can occur during surgery, secondary to injury e.g. bites, wounds.
Bacteria can spread into the joint causing septic arthritis by either direct inoculation or via haematogenous spread.
Which is the most common mechanism
Haematogenous spread
Bacteria can spread into the joint causing septic arthritis by either direct inoculation or via haematogenous spread.
Describe some of the ways direct inoculation occurs
During surgery
Secondary to injury e.g. bites, wounds
Describe the clinical features of septic arthritis
Hot, swollen acutely painful joint with restriction of movement
Usually only affects a single joint
Systemically symptoms e.g. fever, lethargy, sepsis
What are the two key investigations used in septic arthritis
- Joint aspiration – synovial fluid sample
- Bloods and culture
Identifying the underlying organism and resistance pattern is key
When should joint aspiration and bloods and cultres be done
As soon as there is clinical suspicion.
Obtained prior to empirical IV antibiotics
What is the key treatment in septic arthritis
IV antibiotics
Alongside IV antibiotics, what other things can be used to aid the management of septic arthritis
Considering joint washout under general anaesthetic
Physiotherapy after acute infection resolves
In a patient with a native joint, what is the first line antibiotics of choice for treating septic arthritis
Flucloxacillin plus rifampicin
Remember to always follow local guidelines though
In a patient with a prosthetic joint, what is the first line antibiotics of choice for treating septic arthritis
If prosthetic joint use vancomycin instead of flucloxacillin
Vancomycin plus rifampicin
What is the normal course of antibiotics for treating septic arthritis
Continue for 3-6 weeks
What patients should be referred to orthopaedics for septic arthritis management
Those with Prosthetic joints
Or those in which the septic joint is inaccessible e.g. hip
Name 3 potential complications of septic arthritis (if left untreated)
Osteomyelitis (infection of the bones)
Arthritis
Ankylosis fusion (fusing of the bones)
