Septic arthritis is an infection of a joint that causes inflammation. It occurs when bacteria or other microorganisms spread through the bloodstream from another infected site in the body and enter the joint space. Common symptoms include pain, swelling, warmth and reduced range of motion in the infected joint. Diagnosis involves synovial fluid analysis, blood tests and imaging. Treatment requires intravenous antibiotics and may also involve surgical drainage and debridement of the joint. Complications can include bone and cartilage destruction, joint fibrosis or ankylosis if not treated promptly.

1. SEPTIC
ARTHRITIS
BY:
MRS.Keerthi Samuel
Asst.Professor,
Vijay Marie CON

2. INTRODUCTION
 Septic arthritis is the inflammation of a joint
due to an infection usually involving the
synovial membrane.
 The infections occurs as the pathogens travel
through the blood stream from another part of
the body.
 It can also occur through penetrating injuries
to the joint.
 Knees are the most commonly affected joints
followed by hipshoulder and other joints.

3. DEFINITION
 Septic arthritis, also known as joint
infection or infectious arthritis, is the invasion
of a joint by an infectious agent resulting in joint
inflammation Symptoms typically include
redness, heat and pain in a single joint
associated with a decreased ability to move the
joint.
 Septic arthritis is inflammation of a synovial
membrane with purulent effusion into the joint
capsule, due to infection.

5. ETIOLOGY
The bloodstream from an infection
elsewhere (most common)
Direct penetration into the joint
(arthrocentesis, arthroscopy, trauma)
A surrounding infection in
the bone or tissue (uncommon,
from osteomyelitis,
septic bursiti, abscess)

6.  Microorganisms in the blood may come from
infections elsewhere in the body such as wound
infection, UTI, meningitis or endocarditis. Joints
with preexisting arthritis, such as rheumatoid
arthritis, are especially prone to bacterial arthritis
spread through the blood.
 In addition, some treatments for rheumatoid
arthritis can also increase a person's risk by
causing an immunocompromised state.
 Intravenous drug use can cause endocarditis that
spreads bacteria in the bloodstream and
subsequently causes septic arthritis
ETIOLOGY

7. CAUSATIVE ORGANISMS

8. RISK FACTORS
 Age over 80 years
 Diabetes mellitus
 Osteoarthritis
 Rheumatoid arthritis. Risk of septic arthritis increases
with anti-tumor necrosis factor alpha treatment.
 Immunosuppressive medication
 Intravenous drug abuse
 Recent joint surgery
 Hip or knee prosthesis and skin infection
 HIV infection
 Other causes of sepsis

9. PATHOPHYSIOLOGY
Formation of pus in the joint followed by erosion and destruction of the joint
formation of seropurulent exudates which results in increased synovial fluid.
Initiation of the inflammatory reaction resulting in production of destructive enzymes by
the bacteria and enzymes released from synovium and inflammatory cells.
As the synovial membrane is highly vascularized the bacteria enters into the synovial joint
via blood stream
Entry of micro organisms through one of the three ways (Hematogenous, direct
inoculation, direct spread from adjacent focal infection).

10. PATHOPHYSIOLOGY
Healing with: Complete resolution 1. Partial loss of articular cartilage
and
1.2. fibrosis of joint
2. 3.Loss of articular cartilage and bony ankylosis
3.4.Bony destruction and permanent deformity
If left untreated, it will spread to the underlying bone and out of joint to
form abscess and sinus.

11. • In the early stage, there is an acute synovitis with a purulent joint effusion
• Soon the articular cartilage is attacked by bacterial and cellular enzyme.
• If infection is not arrested , the cartilage may be completely destroyed
• Healing then leads to ankylosis

12. CLINICAL FEATURES
 Pain, swelling and warmth at the affected joint resulting in refusal to use
the extremity and prefer to hold the joint rigidly.
 Fever is also a symptom; however, it is less likely in older people.
 On physical examination, the septic joint should be ruled out of intra-
articular (from inside the joint) or periarticular (around the joint such
as bursa and skin) cause. Intra-articular arthritis usually results in severe
limitation of the range of movement of the joint with the joint held in
extended position; the joint space will be maximal in this position. In peri-
articular arthritis, pain only occurs when the joint is moved, and the lesion
usually lies in one specific area around the joint.
 Patient with rheumatoid arthritis and especially those on corticosteroid
maydevelop “silent” joint infection.

13. CLINICAL FEATURES
 Physical examination:
• Lower limb antalgic limp / cannot walk
• Upper limb affected part is closedly guarded
• Marked tenderness, active and passive range of motion are
limited
• Examine for synovial effusion, erythema, heat and
tenderness.
• Spasm of muscles around the joint may be marked.
• Patient may hold the joint in a position to reduce the intra-
articular pressure to minimize pain.

14. DIAGNOSTIC FEATURES-BLOOD TESTS
 Laboratory testing includes white blood cell count, ESR and CRP. These values are
usually elevated in those with septic arthritis; however, these can be elevated by other
infections or inflammatory conditions and are, therefore, nonspecific.
 Procalcitonin may be more useful than CRP.
Investigations Explaination
Full blood count Elevated white blood cell count
ESR > 40 mm/hr
CRP > 20 mg/dL
Blood culture May be positive

15. DIAGNOSTIC FEATURES-SYNOVIAL FLUID ANALYSIS
 Synovial fluid analysis
 Aseptic technique is used during aspiration of synovial fluid.
 Avoid taken from infected site of skin.
The fluid is then analyzed by gross and microscopic examination and culture.
Gross examinations include appearance, volume, viscosity, mucin clotting (amount of
proteoglycans).
Microscopic examinations include leucocyte count, staining of smears, serum glucose ratio,
protein.
Finally, culture and sensitivity for definitive diagnosis and treatment.

17. DIAGNOSTIC FEATURES-IMAGING
 X ray
 Early Stage – Normal
Look for soft tissue swelling, loss of tissue planes, widening of joint space and slight
subluxation due to fluid in joint. Gas may be seen with E. coli infection
 Late stage – Narrowing and irregularity of joint space
Plain film findings of superimposed osteomyelitis may develop (periosteal reaction, bone
destruction, sequestrum formation).

18. DIAGNOSTIC FEATURES-IMAGING
osteonecrosis and
complete collapse of the
femoral head
NARROWING OF JOINT SPACE AND
IRREGULARITY OF SUBCHONDRAL
BONE.

19. DIAGNOSTIC FEATURES-ULTRASONOGRAPHY
• More reliable in revealing a joint effusion in early cases.
• Widening of space between capsule and bone of > 2mm indicates effusion.
• Echo-free transient synovitis
• Positively echogenic septic arthritis

20. MANAGEMENT-MEDICAL
 Empiric antibiotics for suspected bacteria should be started. This should be based
on Gram stain of the synovial fluid as well as other clinical findings. General guidelines
are as follows:
 Gram positive cocci – vancomycin
 Gram negative cocci – Ceftriaxone
 Gram negative bacilli – Ceftriaxone, cefotaxime, or ceftazidime
 Gram stain negative and immunocompetent – vancomycin
 Gram stain negative and immunocompromised– vancomycin + third
generation cephalosporin
 IV drug use (possible pseudomonas aeruginosa) – ceftazidime +/- an aminoglycoside

21. MANAGEMENT
 Once cultures are available, antibiotics can be changed to target the specific
organism.
 After a good response to intravenous antibiotics, people can be switched to oral
antibiotics. The duration of oral antibiotics varies, but is generally for 1–4
weeks depending on the offending organism.
 use of corticosteroids may reduce pain and the number of days of antibiotic
treatment in children.

22. SURGICAL MANAGEMENT
 Repeated daily joint aspiration is useful in the treatment of septic arthritis.
Every aspirate should be sent for culture, gram stain, white cell count to
monitor the progress of the disease.
 Both open surgery and arthroscopy are helpful in the drainage of the infected
joint. During surgery, lysis of the adhesions, drainage of pus, and debridement
of the necrtoic tissues are done.
 Close follow up with physical exam & labs must be done to make sure the
person is no longer feverish, pain has resolved, has improved range of motion,
and lab values are normalized.

23. COMPLICATIONS
 Bone destruction and dislocation of the joint (esp Hip)
Cartilage destruction
 -may lead to either fibrosis or bony ankylosis
 - in adult partial destruction of the joint will result in secondary osteoarthritis
Growth disturbance
 - presenting as either localised deformity or shortening of the bone