Fractures

Question 1

What are the prerequesites for proper bone healing?

Answer 1

The prerequisites for proper bone healing are:

• Blood supply with nutrients to bone and periosteum
• Minimal gap between fracture pieces
• A little bit of movement at the fracture site to stimulate adequate osteoblast proliferation

Question 2

What are the stages of fracture healing?

Answer 2

There are three phases of fracture healing:

1. Reactive phase: up to 48 hours. Bleeding into the site of fracture leads to formation of a haematoma. This also leads to inflammation and release of cytokines, growth factors and thus to the recruitment of leukocytes and fibroblasts. Granulation tissue is formed.
2. Reparative phase: 2 days - 2 weeks.
   
   1. Proliferation of osteoblasts and fibroblasts, leading to new cartilage formation - soft callus is formed.
   2. Consolidation means that osteoid and woven bone is put down - hard callus formation.
3. Remodelling phase: up to 7 years. Bone is remodelled via endochondral ossification and lamellar bone is put down. The lamellar bone is remodelled to cope with the mechanical forces applied to it.
   
   • Wolff’s Law: bone grown remodels in response to the forces that are placed on it; “form follows function”.

Question 3

What are the types of fractures based on aetiology?

Answer 3

Causes of fractures can be classified as follows:

• Traumatic: a strong force has been applied to the bone causing it to fracture
  
  • Direct: trauma directly onto fractured bone
  • Indirect: trauma transmitted via other body parts
  • Avulsion: when strong force applied to tendon and it rips of a bitt of bone
• Stress fracture: repetitive strain
  
  • Small amounts of force over time leading to fracture
  • E.g. stress fracture in foot or shin in runners
• Pathological: fractures despite forces thought too weak to break
  
  • Tumours
  • Osteopenia due to osteoporosis or osteomalacia

Question 4

What is the general approach to fracture management?

Answer 4

• Resuscitation
• Reduction
• Restriction
• Repair (?)
• Rehabilitate

Question 5

What is the general management of open fractures?

Answer 5

Open fractures require urgent attention (6 As):

• Analgesia
• Assess: neurovascular status documented, soft tissues, medical photographs
• Antisepsis: wound swab, copious irrigation, cover with betadine-soaked dressing
• Alignment: align fracture and splint
• Anti-tetanus: check status (booster status lasts 10 years)
• Antibiotics: usually flucloxacillin + benzylpenicillin.

Definitive management: debridement and fixation in theatre (aim < 6 hours). Don’t close the wound.

• C. perfringens is the most dangerous complication of an open fracture. It can cause wound infections with gas gangrene. Treat with debridement, benpen + clindamycin.

Question 6

How can fractures be reduced?

Answer 6

Displaced fractures should be reduced (unless if in the ribs because it has no effect on outcome). Reduction is simply putting the bones close to each-other so that healing can occur.

There are two main approaches to reduction:

• Closed reduction - the manipulation of bone fragments without surgical exposure of the fragments. This is usually done under local, regional or general anaesthetic.
  
  • Traction may be used to dis-impact - done less today, but usually to overcome contraction of large muscles such as in femoral fractures. Can be skin traction using tapes and bandages, or skeletal traction using bone pin/nail.
• Open reduction - where the fracture fragments are exposed surgically by dissecting the tissues.

Question 7

What are the methods of fracture restriction?

Answer 7

Methods:

• Non-rigid - slings and supports
• Plaster fixation:
  
  • Full casts - plaster of Paris (POP) or fibreglass
  • Equinus cast for Achilles’ tendon fracture. Traditionally, foot and ankle surgeons would immobilize the ankle in a cast with the ankle set at 30 degrees plantarflexion (equinus) for a minimum of eight weeks after surgical repair of the Achilles tendon.
  • Backslab casts are not complete casts and are usually placed for first 24-48 hours to allow swelling in limbs space to prevent compartment syndrome.
• External fixation:
  
  • Fragments held in position by pins/wires which are then connected to an external frame
  • Used in open fractures when there is a high risk of injury, or when there is risk of tissue loss (e.g. in burns) to allow access to the wound.
  • There is a risk of pin-site infections
• Internal fixation:
  
  • Consists of pins, plates, screws, and IM nails
  • Usually leads to the best anatomical alignment
  • Facilitates early mobilisation

Question 8

What are the methods of rehabilitation following a fracture?

Answer 8

Immobility leads to a reduction in muscle mass of approximately 50% within 2 weeks! Therefore need to maximise mobility of uninjured limbs, as well as maintaining muscle surrounding fracture.

Methods:

• Physiotherapy: exercise regime
• Occupational therapy: splints, mobility aids, home modification
• Also help with day-to-day activities - e.g. meals-on-wheels, care help

Question 9

Describe the Salter-Harris classification of fractures

Answer 9

Salter-Harris Classification can be remembered by the mneumonic SALTCRUSH:

1. Straight through the epiphysis
2. Above (through growth plate and metaphysis)
3. Lower (through growth plate and epiphysis)
4. Trough all three elements
5. CRUSH injury