BONE AND JOINT INFECTION

Question 1

What do we call infection of the bone?

Answer 1

Osteomyelitis

Question 2

What is the usual source of infection in osteomyelitis cases?

Answer 2

Haematogenous spread - often secondary to infected wound

Question 3

Where in the bone does osteomyelitis usually start?

Answer 3

In the metaphysis, where there is relative stasis of blood

Question 4

Which bones are most often affected by osteomyelitis?

Answer 4

2/3rds of cases occur in femur or tibia

Question 5

What is the peak age of incidence for osteomyelitis?

Answer 5

Neonatal period

9-11 year children

Question 6

What is the pathogen most commonly responsible for osteomyelitis?

Answer 6

S. aureus

Question 7

Other than s. aureus, what pathogens are known to commonly cause osteomyelitis in children?

Answer 7

Group B streptococcus

E. coli - neonates only

Should also consider M. tuberculosis

Question 8

Which group of patients are more at risk of developing osteomyelitis?

Answer 8

Sickle cell disease

Question 9

Osteomyelitis caused by what other pathogen are children with sickle cell disease particularly prone to?

Answer 9

Salmonella osteomyelitis

Question 10

What are the clinical features of osteomyelitis in a child?

Answer 10

Fever

Pain

Limp

Refusal to move affected limb

Exquisite tenderness over affected bone

Red, warm area

Question 11

What are the investigations that should be done in someone who presents with signs and symptoms consistent with osteomyelitis?

Answer 11

FBC - raised WCC

CRP - raised

ESR - raised

Blood cultures

Bone aspiration for culture and antibiotic sensitivity

Imaging

Question 12

What imaging should be done for a child who presents with osteomyelitis?

Answer 12

MRI, USS and bone scans are more sensitive in the early phase of illness (24-48 hours)

X-rays tend to be normal for the first 10 days

Question 13

How do we manage a child with osteomyelitis?

Answer 13

Urgent IV antibiotics until clinical improvement and normalising of acute phase reactants.

Oral antibiotics for several weeks after coming off IV.

Surgical drainage may be indicated if non-adequate response to antibiotics.

Question 14

What antibiotics should be used in the treatment of osteomyelitis?

Answer 14

Flucloxacillin and sodium fusidate

Question 15

What antibiotics should be used in the treatment of osteomyelitis in a patient who is allergic to penicillin?

Answer 15

Clindamycin

Question 16

What antibiotics should be used in the treatment of osteomyelitis where salmonella is suspected as the causative organism?

Answer 16

Ceftriaxone

Question 17

What are the complications of osteomyelitis?

Answer 17

Chronic osteomyelitis

Septic arthritis

Growth disturbance and limb deformity - especially if infection affects epiphyseal plate)

Question 18

Which is more common in kids: osteomyelitis or septic arthritis?

Answer 18

Septic arthritis

Question 19

In what age group is the incidence of septic arthritis highest?

Answer 19

Younger than 3 years old

Question 20

What is the main source of infection for septic arthritis?

Answer 20

Haematogenous spread

Question 21

What is the most common site of septic arthritis in infants?

Answer 21

Hip

Question 22

What is the most common site of septic arthritis in older children?

Answer 22

Knee

Question 23

What is the pathogen most commonly responsible for septic arthritis?

Answer 23

S. aureus

Question 24

What are the clinical features of septic arthritis in a child?

Answer 24

Fever

Irritability

Refusal to weight bear

Infants will often hold limb rigid (pseudoparalysis)

Tenderness over joint

Red, hot and swollen

Question 25

What investigations should be done for a child who presents with signs and symptoms consistent with septic arthritis?

Answer 25

FBC - raised WCC

CRP - raised

ESR - raised

Aspiration of joint space - white cells and culture

USS - effusions

X-ray - non-specific, widened joint space

Question 26

How do we manage a child with septic arthritis?

Answer 26

Urgent IV antibiotics until clinical improvement and normalising of acute phase reactants.

Oral antibiotics for several weeks after coming off IV.

Surgical drainage may be indicated if non-adequate response to antibiotics.

Question 27

What antibiotics should be used in the treatment of septic arthritis?

Answer 27

Flucloxacillin and sodium fusidate