Bone & Soft Tissue Infection

Question 1

What is infection of the bone referred to as?

Answer 1

Osteomyelitis

Question 2

How is osteomyelitis classified?

Answer 2

1) Acute
2) Chronic
1) Specific (e.g. TB)
2) Non-specific (most common)

Question 3

What is the pathological process involved in bone infection?

Answer 3

• Spreads from metaphysis (possibly caused by trauma?)
• Leukocytes release enzymes which lyse the bone
• Spread of infection from metaphysis results in venous congestion and arterial thrombosis
• Acute inflammation occurs as a result of the infection and produces increased pressure

Question 4

What is the most common bacteria involved in acute osteomyelitis?

Answer 4

Staph Aureus

Question 5

What are the common sources of infection in osteomyelitis?

Answer 5

1) Spread via blood
2) Local spread from site of infection - trauma, bone surgery
3) Vascular insufficiency

Question 6

What is the aetiology of acute osteomyelositis?

Answer 6

Acute osteomyelitis:

• Mostly children
• Boys > girls
• History of trauma
• Common with other diseases (diabetes, RA, immune compromised, long-term steroids)

Question 7

What are the common bacterias involved in chronic osteomyelitis?

Answer 7

• Staph Aureus
• E. Coli
• Strep Pyogenes

Question 8

What are the clinical features of an infant with osteomyelitis?

Answer 8

1) Failure to thrive
2) Metaphyseal tenderness + swelling
3) Decreased range of motion
4) Knee most commonly affected

Question 9

What are the clinical features of a child with osteomyelitis?

Answer 9

1) Severe pain
2) Reluctant to move and not weight bearing
3) Fever and tachycardia
4) Malaise

Question 10

What are the clinical features of an adult with osteomyelitis?

Answer 10

1) Commonly seen in thoracolumbar spine (primary)
2) Backache
3) History of UTI
4) Elderly, diabetic, immunocompromised
5) Secondary OM after open fractures or surgery

Question 11

What are the differential diagnosis of acute osteomyelitis?

Answer 11

1) Acute septic arthritis
2) Acute inflammatory arthritis
3) Trauma
4) Transient synovitis
5) Soft tissue infection

Question 12

What are the clinical features of acute septic arthritis in a neonate?

Answer 12

1) Irritability
2) Resistant to movement
3) ill

Question 13

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

Answer 13

1) Acute pain in single large joint
2) Reluctance to move joint
3) Increased temperature and pulse
4) Increased tenderness

Question 14

What are the differential diagnosis of acute septic arthritis?

Answer 14

1) Acute osteomyelitis
2) Trauma
3) Haemophilia
4) Rheumatic fever
5) Gout

Question 15

What are the investigations and expected results of acute osteomyelitis?

Answer 15

1) Clinical examination - raised temp and pulse
2) ESR, CRP - raised
3) FBC - Raised neutrophils
4) Blood cultures - +ve
5) U+E’s - dehydrated

Question 16

What are the investigations and expected results of septic arthritis?

Answer 16

1) FBC, WBC, ESR, CRP, Blood cultures
2) Radiograph
3) USS
4) Aspiration

Question 17

What are the principles of management of bone and soft tissue infections?

Answer 17

1- Supportive treatment for pain + dehydration (general care, analgesia)

2 - Rest + splintage

3) Antibiotics
4) Surgery

Question 18

What are the possible complications of bone and soft tissue infections?

Answer 18

1 - Septicaemia, death

2 - Metastatic infection

3 - Pathological fracture

4 - Septic arthritis

5 - Altered bone growth

6 - Chronic osteomyelitis

Question 19

What are the medical names for necrotised and new bone?

Answer 19

• Necrotised bone is known as sequestrum
• New bone formed is known as involucrum

Question 20

What is the aetiology of chronic osteomyelitis?

Answer 20

Chronic osteomyelitis:

• Can follow acute osteomyelitis
• May start on its own (e.g. post-operative)
• Breakdown of healed wounds

Question 21

Is secondary or primary acute osteomyelitis more common?

Answer 21

Secondary

Question 22

At what stage in acute osteomyelitis will x-rays begin to show abnormalities?

Answer 22

10 days onwards