2. Septic arthritis is an inflammation of synovial membrane
with purulent effusion into the joint capsule due to
infection.
Also referred as infectious arthritis
Septic arthritis is a key consideration in adults presenting with
acute monoarticular arthritis.
Considered as medical emergency
Failure to initiate appropriate antibiotic therapy within the
first 24 to 48 hours of onset can cause subchondral bone loss
and permanent joint dysfunction.
It can cause septic shock, which can be fatal.
DEFINITION
WHAT IS SEPTIC ARTHRITIS?
3. ANATOMY
SYNOVIAL JOINT
Protection of joint cavity
Lines joint & cavity and
secretes synovial fluid for
lubrication
Prevents grinding of the
bone and allow for
smooth articulation
5. The prevalence of bacterial arthritis as the diagnosis among adults
presenting with one or more acutely painful joints has been estimated to
range from 8% - 27%
All age groups, infants and older adults are most likely to develop septic
arthritis.
50% < age 3
M = F
The knee is the most commonly affected but any joint may be involved.
EPIDEMIOLOGY
Infants Hip
Children Knee
Adults Large joints
IVDU Sacrioliac joint
6. The infection can originate anywhere in the body.
May also begin as the result of an open wound, trauma, surgery, or
unsterile injection.
Septic arthritis occurs when the infective organism travels through blood
stream to the joint.
The infection can be caused by bacteria, virus or fungus.
AETIOLOGY
9. AETIOLOGY
1. AGE
2. EXISTING JOINT PROBLEMS
3. MEDICATIONS
Age > 80 years old
Chronic diseases and conditions that affect the joints — such as osteoarthritis, gout, rheumatoid
arthritis or lupus — can increase the risk of septic arthritis, as can an artificial joint, previous joint
surgery and joint injury.
Taking medications for rheumatoid arthritis. People with rheumatoid arthritis have a further
increase in risk because of medications they take that can suppress the immune system, making
infections more likely to occur. Diagnosing septic arthritis in people with rheumatoid arthritis is
difficult because many of the signs and symptoms are similar.
4. SKIN FRAGILITY
Skin that breaks easily and heals poorly can give bacteria access to your body. Skin conditions such
as psoriasis and eczema increase your risk of septic arthritis, as do infected skin wounds. People
who regularly inject drugs also have a higher risk of infection at the site of injection.
10. AETIOLOGY
5. WEAK IMMUNE SYSTEM
6. ALCOLOISM AND IVDU
People with a weak immune system are at greater risk of septic arthritis. This includes people with
diabetes, kidney and liver problems, and those taking drugs that suppress their immune systems.
Having a combination of risk factors puts you at greater risk than
having just one risk factor does.
13. PATHOPHYSIOLOGY
HEMATOGENOUS SPREAD
DIRECT INNOCULATION
Most common form of spread, usually
affects people with underlying medical
problems.
May result from penetrating trauma,
introduction of organisms during
diagnostic and surgical procedures.
E.g. intra-articular injection.
DIRECT SPREAD FROM ADJACENT BONE
More common in children. Osteomyelitis usually begins in the metaphyseal region,
from which it breaks through the periosteum into the joint
20. WHAT IS NEXT?
SEPTIC ARTHRITIS SUSPECTED
BLOOD AND SYNOVIAL FLUID SAMPLE
EMPIRIC PARENTERAL ANTIBIOTICS BASED ON GRAM STAIN
JOINT DRAINAGE
ADJUST ANTIBIOTICS BASED ON CULTURE AND SENSITIVITY RESULT
21. INVESTIGATIONS
1. BLOOD INVESTIGATIONS
Raised WCC
Raised ESR and CRP
Blood culture (positive)
2. IMAGING
X-ray
Early stage: May look normal except widening of joint space, ultrasound helpful
Late stage: Narrowing and irregularity of joint space; may have OM changes of
adjacent bones
MRI and radionuclide imaging are helpful in diagnosing arthritis in obscure sites
such as the sacroiliac and sterno-clavicular joint.
3. SYNOVIAL FLUID ANALYSIS
31. KOCHER CRITERIA
Kocker et al in 1999: the presence or absence of the above 4 clinical predictors could be
used to accurately predict the likelihood of a septic hip in a child with limp.
32. TREATMENT
1st priority – aspirate the joint and examine the fluid
General supportive care – analgesics and IV fluid
Splintage
Antibiotics
a. Neonates and infants up to 6 months – penicillin ( flucloxacillin) + 3rd gen
cephalosporin
b. Children from 6 months to puberty – similar to above.
c. Older teenager and adults – flucloxacillin and fusidic acid and 3rd
generation cephalosporin
Antibiotics given IV for 4-7 days, then orally for 3 weeks.
34. COMPLICATIONS
1. Bone destruction and dislocation of the joint (especially hip)
2. Cartilage destruction
3. May lead to either fibrosis or bony ankylosis
4. In adult partial destruction of the joint will result in secondary
osteoarthritis
5. Growth disturbance
6. Presenting as either localized deformity or shortening of the
bone
Editor's Notes
Septic arthritis of the sacroiliac joint is a relatively rare disorder, affecting between 1% and 2% of all patients with septic arthritis.
AETIOLOGY
S aureus
Most common pathogen in infectious arthritis of both native & prosthetic joints
Infections caused by Methicillin-resistant S aureus are usually more aggressive, w/ involvement of >1 joint
S epidermidis
More common in prosthetic joint infection
Streptococci
Next to S aureus, most common Gram positive aerobes causing infectious arthritis
Group B streptococci is a common cause of infectious arthritis in neonates while S pyogenes & S pneumoniaeare are common pathogens in children ≤ 5 years old who have infectious arthritis
Streptococci are important infectious arthritis pathogens in patients w/ serious infections of the genitourinary or gastrointestinal tract
Gram-negative bacilli
Common etiologic agents of infectious arthritis in intravenous (IV) drug users, elderly & immunocompromised persons
Elderly patients frequently have underlying joint diseases & concomitant diseases like diabetes mellitus (DM) & rheumatoid arthritis
Disease-modifying drugs used to treat rheumatoid arthritis (eg Infliximab & Etanercept) may predispose patients to the development of infectious arthritis
H influenzae was formerly a common pathogen in infectious arthritis in children aged 1 month-5 years but widespread vaccination against the organism has drastically reduced the number of cases
P aeruginosa may be a cause of infectious arthritis in IV drugs users, premature infants & patients w/ central vascular catheters
N gonorrhoeae
Possible etiologic agent in young, healthy, sexually active adults w/ infectious arthritis
Incidence frequently related to socioeconomic status
Anaerobes
More common in patients w/ DM & those w/ prosthetic joint infection
Mycobacterial species & fungi
Much less common cause of infectious arthritis compared to bacteria
Low immune system, recent travel & living in endemic areas are determinants for people susceptible to mycobacterial infections
Infectious arthritis caused by these organisms usually presents w/ marked joint swelling, mild signs of acute inflammation & few systemic symptoms
Tuberculous infectious arthritis may be more common in low-income groups while other mycobacterial species can cause infectious arthritis in human immunodeficiency virus (HIV)-infected persons
Candida arthritis is more common in immunocompromised persons & is associated w/ the presence of a central vascular catheter
MIMS MALAYSIA
https://specialty.mims.com/infectious%20arthritis/signs%20and%20symptoms?channel=infectious-diseases