Osteomyelitis

Question 1

What is osteomyelitis?

Answer 1

An infection of the bone

Osteomyelitis can be subclassified into haematogenous and non-haematogenous types.

Question 2

What characterizes haematogenous osteomyelitis?

Answer 2

Results from bacteraemia, usually monomicrobial, and is the most common form in children

Vertebral osteomyelitis is the most common form in adults.

Question 3

What are the risk factors for haematogenous osteomyelitis?

Answer 3

• Sickle cell anaemia
• Intravenous drug use
• Immunosuppression (medication or HIV)
• Infective endocarditis

These factors increase susceptibility to infections that can lead to osteomyelitis.

Question 4

What defines non-haematogenous osteomyelitis?

Answer 4

Results from contiguous spread of infection or direct injury/trauma to bone, often polymicrobial, and is the most common form in adults

This type is primarily associated with conditions affecting soft tissues.

Question 5

What are the risk factors for non-haematogenous osteomyelitis?

Answer 5

• Diabetic foot ulcers/pressure sores
• Diabetes mellitus
• Peripheral arterial disease

These conditions can lead to infections that affect the bones.

Question 6

What is the most common microbiological cause of osteomyelitis?

Answer 6

Staph. aureus, except in sickle-cell anaemia patients where Salmonella species predominate

Understanding the microbiology helps in targeted treatment.

Question 7

What is the imaging modality of choice for investigating osteomyelitis?

Answer 7

MRI, with a sensitivity of 90-100%

MRI is preferred due to its ability to detect bone infections accurately.

Question 8

What is the first-line management for osteomyelitis?

Answer 8

Flucloxacillin for 6 weeks

Alternative treatment includes clindamycin for those allergic to penicillin.

Question 9

Fill in the blank: The most common form of haematogenous osteomyelitis in adults is _______.

Answer 9

vertebral osteomyelitis

This highlights the difference in presentation between children and adults.

Question 10

True or False: Non-haematogenous osteomyelitis is usually monomicrobial.

Answer 10

False

Non-haematogenous osteomyelitis is often polymicrobial.

Question 11

Which organism to suspect causing osteomyelitis in unvaccinated child?

Answer 11

Haemophilius influenzae

Question 12

Which organism to suspect causing osteomyelitis in IV drug user?

Answer 12

Pseudomonas aeruginosa

Question 13

Which organism to suspect causing osteomyelitis in sickle cell?

Answer 13

Salmonella

Question 14

What is the ideal imaging for osteomyelitis?

Answer 14

MRI

Question 15

What causes Fever/back pain with pain on extension of the hip?

Answer 15

Iliopsoas abscess

Question 16

What is the most common cause of iliopsoas abscess!

Answer 16

Staphyloccocus aureus

Question 17

What is a common secondary cause of iliopsoas abscsss?

Answer 17

Crohn’s disease

Question 18

What factors are linked to iliopsoas abscsss?

Answer 18

Higher mortality than priamry abscsss and linked to:

*Crohn’s (commonest cause in this category)
*Diverticulitis, colorectal cancer
UTI, GU cancers
*Vertebral osteomyelitis
*Femoral catheter, lithotripsy
*Endocarditis
intravenous drug use

Question 19

What investigation is ideal for iliopsoas abscsss suspicion?

Answer 19

*CT abdomen is the investigation of choice

*hyperextend the affected hip. This should elicit pain as the psoas muscle is stretched.

Question 20

How to manage iliopsoas abscsss.

Answer 20

Antibiotics
Percutaneous drainage

Question 21

What to do if Percutaneous drainage does not resolve iliopsoas abscsss?

Answer 21

Surgery is indicated if:
1. Failure of percutaneous drainage
2. Presence of an another intra-abdominal pathology which requires surger