Osteomyelitis + open fracture + bone tumours + bursitis

Question 1

Osteomyelitis is an infection of the bone.

Which bones are most commonly affected?

Answer 1

In adults, the vertebrae are the most commonly affected. In children, the long bones are more commonly affected.

Question 2

How does the bone become infected in osteomyelitis?

Answer 2

• Haematogenous spread
• Direct inoculation of micro-organisms into the bone (eg following an open fracture or penetration injury)
• Direct spread from nearby infection (eg septic arthritis)

Question 3

Risk factors for developing osteomyelitis

Answer 3

• Diabetes mellitus
• Immunosupression (such as long term steroid treatment or AIDS)
• Alcohol excess
• Intravenous drug use

Question 4

Clinical features of osteomyelitis

Answer 4

• Severe pain in the affected area (may be absent in diabetic foot due to peripheral neuropathy)
• Low grade pyrexia
• Tender
• Overlying swelling and erythema

Question 5

Differentials for osteomyelitis

Answer 5

• Septic arthritis
• Traumatic injuries (including soft tissue injury and fractures)
• Primary or secondary bone tumours

Question 6

Investigations for osteomyelitis

Answer 6

• Routine blood tests: FBC, CRP, ESR
• Blood cultures
• Plain film radiographs (often performed however poor accuracy for osteomyelitis)
• MRI imaging for definitive diagnosis
• Gold standard diagnosis is from culture from bone biopsy at debridement

Question 7

Management of osteomyelitis

Answer 7

• If patient clinically well:
  
  • long term intravenous antibiotic therapy (>4 weeks)
• If patient deteriorates (clinically deteriorates, the limb shows evidence of deterioration, or imaging shows progressive bone destruction):
  
  • surgical management to prevent chronic osteomyelitis from developing. This involves curettage of the area.

Question 8

What is meant by an open fracture?

Answer 8

There is a direct communication between the fracture site and the external environment.

Question 9

What are the most common open fractures?

Answer 9

• Tibial
• Phalangeal
• Forearm
• Ankle
• Metacarpal

Question 10

How do patients with an open fracture present?

Answer 10

With pain, swelling and deformity, with an overlying wound or punctum.

Question 11

What are the most important aspects of examination for an open fracture?

Answer 11

• Check neurovascular status
• Check overlying skin for any skin or tissue loss
• Contamination should be assessed for and documented
  
  • Marine, agricultural and sewage contamination is of the highest importance

Question 12

How is an open fracture classified?

Answer 12

Gustilo-Anderson classification

• Type 1: <1cm wound and clean
• Type 2: 1-10cm wound and clean
• Type 3A: >10cm wound and high energy, but with adequate soft tissue coverage
• Type 3B: >10cm wound and high energy, but with inadequate soft tissue coverage
• Type 3C: All injuries with vascular injury

3A requires orthopaedics alone

3B requires plastics input

3C requires vascular input

Question 13

Investigations for open fracture

Answer 13

• Basic blood tests including a clotting screen and group and save
• Plain film radiograph
• For comminuted or complex fracture patterns, a CT scan can often aid management

Question 14

Management of open fracture

Answer 14

• Urgent realignment and splinting of the limb
• Broad spectrum antibiotics
• Tetanus vaccination
• Remove any gross debris
• Dress wound with saline soaked gauze

Question 15

How quickly does definitive management of an open fracture need to occur?

Answer 15

Immediately if contaminated with marine, agricultural or sewage material

Otherwise within 12-24 hours

Question 16

Metastatic spread from other cancer types is the most common cause of bone cancer, what are the most common primary sites?

What is the most common site of bony metastasis?

Answer 16

Renal, thyoid, lung, prostate and breast.

The most common site for a bony metastasis is the spine.

Question 17

What are the risk factors for developing a primary bone cancer?

Answer 17

• Genetic association:
  
  • RB1 (familial retinoblastoma) and p53 (Li Fraumeni syndrome) are associated with an increased risk of osteosarcomas
  • Mutations to TSC1 and TSC2 (tuberous sclerosis) are associated with an increased risk of chordomas during childhood
• Previous exposure to radiation or alkylating agents in chemotherapy
• Benign bone conditions, such as Paget’s disease and fibrous dysplasia (both increase risk of osteosarcoma)

Question 18

Clinical features of primary bone tumour

Answer 18

• The main symptoms of primary bone tumour is pain
  
  • ​not associated with movement
  • worse at night (red flag symptom)
• As the tumour enlarges a mass may be palpable
• Pathological fracture (fracture without a history of trauma)

Question 19

Investigations for bone tumour

Answer 19

Plain film radiographs

All suspected cases should be discussed in an appropriate multidisciplinary team meeting before further investigations are arranged.

Question 20

Radiological features of benign and metastatic bone tumours

Answer 20

• Benign lesions are often sharp and well defined, lacking soft tissue involvement and no cortical destruction
• Malignant lesions are often poorly defined with rough boarders, involving soft tissues and have cortical destruction

Question 21

What is bursitis?

Answer 21

Inflammation of the bursa

Question 22

Causes of olecranon bursitis

Answer 22

• Repetitive flexion-extension movements at the elbow causing irritation of the bursa
• Gout
• Rheumatoid arthritis
• Infectinon through skin abrasion or puncture

Question 23

Causes of trochanteric bursitis

Answer 23

• Overuse
  
  • athletes, often runners
  • repeitive movements
• Trauma
• Abnormal movement
  
  • distant problem eg scoliosis
• Local problem
  
  • Muscle wasting following surgery
  • Total hip replacement
  • Osteoarthritis

Question 24

Clinical features of olecranon bursitis

Answer 24

• Pain and swelling over the olecranon
• Range of motion is usually preserved (as the joint capsule is not involved)

Question 25

Investigations for olecranon bursitis

Answer 25

• Routine bloods
• Serum urate levels (if history suggestive of gout)
• Plain film radiographs (to rule out bony injury)
• Aspiration of the fluid (to assess for evidence of infection and for presence of crystals)

Question 26

First line management of bursitis

Answer 26

NSAIDs and rest