Acute suppurative arthritis is a joint infection that can be caused by direct invasion, spread from adjacent bone, or bloodborne transmission. It leads to inflammation of the synovial membrane and accumulation of pus in the joint. Without treatment, the infection can destroy articular cartilage and bone. Clinical features include pain, swelling, warmth and restricted movement of the infected joint. Joint fluid analysis and culture is important for diagnosis and guiding antibiotic treatment, which typically involves drainage and IV or oral antibiotics for several weeks. Complications can include joint damage, deformity and restricted movement if not properly treated.

1. ACUTE SUPPURATIVE ARTHRITIS.
Dr. Muthoka

2. A jt can become infected by;
I. Direct invasion through a penetrating wound, inta-
articular injection or arthroscopy.
II. Direct spread from an adjacent bone abscess.
III. Blood spread from a distant site.
In infants infection start in the metaphyseal
bone(osteomyelitis) then spread to the joint or vice
versa.
Causal organism: staph-aureus.
In children btn 1 & 4 years old; H influenzae,
streptococcus, E-coli, & proteus.
Predisposing conditions: Rh arthritis, chronic
debilitating disorder, IV drug abuse, AIDs

3. PATHOLOGY
• Haematogenous spread.
• Settle in the synovial membrane.
• Acute inflammatory reaction with serous or
seropurulent exudate & an increase in synovial fluid.
• Pus appears in the joint.
• Articular cartilage is eroded & destroyed by bacterial
enzymes & proteolytic enzymes released from synovial
cells, inflammatory cells & pus.
• In infants the epiphysis may be severely damaged.

4. • Older children, vascular occlusion may lead to necrosis
of epiphyseal bone
• In adults the effects are usually confined to the
articular cartilage, but in the late cases there may be
extensive erosion due to synovial proliferation &
ingrowth.
• If untreated, infection spread to the underlying bone or
burst out of the joint to form an abscess & sinuses.
• With healing there may be:
1. Complete resolution & return to normal.
2. Partial loss of articular cartilage & fibrosis of the joint.
3. Loss of articular cartilage & bony ankylosis.
4. Bone destruction & permanent deformity of the joint.

5. CLINICAL FEATURES
• Differ according to age of the patient.
NEW BORN INFANT
• Emphasis is on septicemia rather than jt pain.
• Irritable & refuses to feed.
• Rapid pulse & fever.
• JT;
– FEEL
– Move to elicit local signs of warmth & tenderness.
– Resistance to mvt.
– Examine umbilical cord.

6. CHILDREN
• Acute pain in a single large joint.
• Reluctance to move the joint (pseudoparesis).
• Looks ill, rapid pulse & a swinging fever.
• Skin redness & superficial joint swelling.
• Local warmth & marked tenderness.
• All movements are restricted & often completely
abolished by pain & spasm.
• Source of infection; septic toe, boil or discharge
from ear.

7. Adults
• Often a superficial joint: knee, wrist, a finger,
ankle or toe that is painful swollen &
inflamed.
• Warmth & local tenderness.
• Mvts are restricted.
• Pt should be questioned & examined for
gonococcal infection or drug abuse.
• Pt on rheumatoid arthritis rx may develop a
silent joint infection.

8. imaging
u/s- reveal joint effusion in early cases.
X-ray;- usually normal.
• watch out for;
• Soft tx swelling.
• Loss of tx planes.
• Widening of the radiographic joint space.
• & slight subluxation because of fluid in the joint.
• E-coli- gas.
• Narrowing & irregularity of joint space.
Mri & radionuclide imaging in obscure sites eg. Sacroiliac.

9. Lab investigations
Raised WCC & ESR.
Blood culture may be +ve.
SPECIAL INVESTIGATIONS
Aspirate joint & examine joint fluid:
– May be purulent.
– Early-clear.
– Aspirate- WCC & gram stain immediately.
– Normal leukocyte count-<300 per ml.
– >10000 per ml in non-infective inflammatory disorders.
– >50000 per ml are suggestive of sepsis.
– Gram –ve cocci; H influenzae or kingella kingae (in
children) gonococcus in adults.

10. Ddx
1. Acute OM.
2. Other types of infection-psoas abscess/ local pelvic infection
3. Trauma-traumatic synovitis/ haemarthrosis/ jt aspiration.
4. Irritable jt; painful & lack mvt. Child is not ill.
5. Rh fever- typically the pain flits from jt to jt
6. JRA-gradual onset with less severe systemic symptoms.
7. Sickle cell dx.
8. Gaucher’s pseudo- osteitis. Acute pain & fever without any
organism.
9. Gout &pseudogout- acute crystal induced synovitis- aspiration;
turbid jt fluid/ raised wcc/ microscopic exam by polarized
microscope show xtic crystals.

11. TREATMENT
• Priority- aspirate joint & examine fluid.
• Start rx without further delay & follow the same principles as AOM.
• If aspirate looks purulent- joint should be drained without waiting
for lab results.
GENERAL SUPPORTIVE CARE
• Analgesics for pain
• Iv fluids-dehydration.
SPLINTAGE
• To rest joint especially in neonates & infants.
• Hip should be abducted & 30 degrees flexed on traction to prevent
dislocation.

12. ANTIBIOTICS
• As AHO.
• Neonates & infants up to 6 months
– penincillinase resistant penincillins eg.-
flucloxacillin & 3rd generation cephalosporins
– Children from 6 months to puberty–similar.
– Older teenagers & adults- flucloxacillin & fusidic
acid.
– 3rd generation cephalosporins- IV for 4-7 days then
orally for 3 weeks.

13. DRAINAGE
• Under anaesthesia.
• Jt is opened through a small incision, drained & washed out
with physiological saline.
• A small catheter is left in place & the wound is closed.
• Suction- irrigation is continued for 2-3 days
• Advisable in
1. very young infants
2. Involving hip
3. Very thick pus aspirated
• Older children; repeated closed aspiration may work.
• If there is no improvement within 48 hours open drainage
is done.

14. complications
Subluxation & dislocation of the hip
Instability of the knee
Damage to cartilagenous physis or epiphysis in growing child.
Sequelae:
• Retarded growth
• Partial or complete destruction of the epiphysis
• Deformity of the joint
• Epiphyseal osteonecrosis
• Acetabular dysplasia
• Pseudoarthrosis of the hip
• Acetabular cartilage erosion( chondrolysis)is seen in older pts & this
may result in restricted mvt or complete ankylosis of the joint.