Septic arthritis

Question 1

What is Septic arthritis

Answer 1

Septic arthritisis a painful infection in ajointthat can come from germs that travel through your bloodstream from another part of your body.Septic arthritiscan also occur when a penetrating injury, such as an animal bite or trauma, delivers germs directly into thejoint.

Question 2

What age group is more likely to develop septic arthritis

Answer 2

Infants

Older adults

Question 3

What joints are commonly infected in septic arthritis

Answer 3

. Knees are most commonly affected, but septic arthritis also can affect hips, shoulders and other joints.

Question 4

What are the routes of infection for septic arthritis

Answer 4

Haematogenous (most common by far)

eruption of bone abscess

direct invasion

• penetrating wound (iatrogenic? – joint injection)
• intra-articular injury
• arthroscopy

Question 5

What is pathophysiology of septic arthritis

Answer 5

Acute synovitis with purulent joint effusion
Articular cartilage attacked by bacterial toxin and cellular enzyme
Complete destruction of the articular cartilage (if left untreated)

Question 6

What organisms cause septic arthritis

Answer 6

Staphylococus aureus
Haemophilus influenzae
Streptococcus pyogenes
E. coli (seen in very young or old

Question 7

What is prognosis for treated septic arthritis

Answer 7

If you catch it early then can get complete recovery before srticular cartilage is damaged

Question 8

What is prognosis for un-treated septic arthritis

Answer 8

If articular cartilage gets damaged a little bit then osteoarthritis may develop years later

If the arthritic isn’t treated and the articular cartilage is destroyed then the patient can get either a FIBROUS or a BONY ankylosis

Question 9

What is ankylosis

Answer 9

A stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease.

Question 10

What is the most common cause of septic arthritis in adult

Answer 10

Infected joint replacement

Question 11

What organism causes Infected joint replacement

Answer 11

s.aureus

Question 12

What is the septic arthritis presentation in a neonate

Answer 12

• Picture of septicaemia
• irritability
• resistant to movement
• ill

Question 13

What is the septic arthritis presentation in a child

Answer 13

• Acute pain in single large joint
• reluctant to move the joint (any movement – c.f. bursitis where RoM OK)
• increase temp. and pulse
• increase tenderness

Question 14

What is the septic arthritis presentation in an adult

Answer 14

• Often involves superficial joint (knee, ankle, wrist)
• Rare in healthy adult
• May be delayed diagnosis (takes 30 days for shoulder)

Question 15

When do you treat septic arthritis

Answer 15

Anyone that you see that has a temperature and a sore joint must be treated as if they have a septic arthritis

Question 16

What are investigations for septic arthritis

Answer 16

FBC, WBC, ESR, CRP, blood cultures
X ray (not abnormal until later)
Ultrasound (useful for deeper joints)
Aspiration and culture aspirate

Question 17

What is treatment for septic arthritis

Answer 17

General supportive measures
Antibiotics (3-4 weeks)
Surgical drainage & lavage - emergency (“never let the sun set on pus” ); open or arthroscopic lavage;
Infected joint replacements - one stage revision, two stage revision, antibiotics only?

Question 18

What are differential diagnosis for septic arthritis

Answer 18

Acute osteomyelitis
Trauma
Irritable joint
Haemophilia
Rheumatic fever
Gout 
Gaucher’s disease (uncommon)

Question 19

What is Haemophilia

Answer 19

Haemophilia is a rare condition that affects the blood’s ability to clot. It’s usually inherited. Most people who have it are male.