Osteomyelitis + open fracture + bone tumours + bursitis Flashcards
Osteomyelitis is an infection of the bone.
Which bones are most commonly affected?
In adults, the vertebrae are the most commonly affected. In children, the long bones are more commonly affected.
How does the bone become infected in osteomyelitis?
- 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)
Risk factors for developing osteomyelitis
- Diabetes mellitus
- Immunosupression (such as long term steroid treatment or AIDS)
- Alcohol excess
- Intravenous drug use
Clinical features of osteomyelitis
- Severe pain in the affected area (may be absent in diabetic foot due to peripheral neuropathy)
- Low grade pyrexia
- Tender
- Overlying swelling and erythema
Differentials for osteomyelitis
- Septic arthritis
- Traumatic injuries (including soft tissue injury and fractures)
- Primary or secondary bone tumours
Investigations for osteomyelitis
- 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
Management of osteomyelitis
- 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.
What is meant by an open fracture?
There is a direct communication between the fracture site and the external environment.
What are the most common open fractures?
- Tibial
- Phalangeal
- Forearm
- Ankle
- Metacarpal
How do patients with an open fracture present?
With pain, swelling and deformity, with an overlying wound or punctum.
What are the most important aspects of examination for an open fracture?
- 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
How is an open fracture classified?
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
Investigations for open fracture
- 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
Management of open fracture
- Urgent realignment and splinting of the limb
- Broad spectrum antibiotics
- Tetanus vaccination
- Remove any gross debris
- Dress wound with saline soaked gauze
How quickly does definitive management of an open fracture need to occur?
Immediately if contaminated with marine, agricultural or sewage material
Otherwise within 12-24 hours
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?
Renal, thyoid, lung, prostate and breast.
The most common site for a bony metastasis is the spine.
What are the risk factors for developing a primary bone cancer?
- 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)
Clinical features of primary bone tumour
- 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)
Investigations for bone tumour
Plain film radiographs
All suspected cases should be discussed in an appropriate multidisciplinary team meeting before further investigations are arranged.
Radiological features of benign and metastatic bone tumours
- 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
What is bursitis?
Inflammation of the bursa
Causes of olecranon bursitis
- Repetitive flexion-extension movements at the elbow causing irritation of the bursa
- Gout
- Rheumatoid arthritis
- Infectinon through skin abrasion or puncture
Causes of trochanteric bursitis
- Overuse
- athletes, often runners
- repeitive movements
- Trauma
- Abnormal movement
- distant problem eg scoliosis
- Local problem
- Muscle wasting following surgery
- Total hip replacement
- Osteoarthritis
Clinical features of olecranon bursitis
- Pain and swelling over the olecranon
- Range of motion is usually preserved (as the joint capsule is not involved)
Investigations for olecranon bursitis
- 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)
First line management of bursitis
NSAIDs and rest
