Fractures 1

Question 1

What are the roles of falls, trauma and osteoporosis in causing fractures?

Answer 1

Falls can cause fractures in abnormal bones eg osteoporotic bones, or if it is a high energy fall
Osteoporosis causes thin bones with increased risk of low trauma fracture
Trauma can cause fractures as high energy transfer

Risk of fracture is related to: age, BMD, falls, bone turnover

Question 2

What is the biology and bio mechanics of fractures?

Answer 2

A fracture is a break in the structural continuity of the bone. May be a crack, break, split, crumpling or buckle.

They can fracture due to: high energy transfer (normal bone), repetitive stress (normal bone), low energy transfer (abnormal bone eg osteoporosis, osteomalacia, other).

Biology: it is a mechanical and structural failure of the bone which disrupts the blood supply. It is regenerative and heals in 4 stages.

Question 3

How is a fracture described?

Answer 3

Complete fracture: transverse, oblique, spiral, comminuted
Incomplete fracture: bowing, buckle, greenstick
Salter Harris (involves the growth plate)

Question 4

What are the clinical features of and investigations into a fracture?

Answer 4

Clinical features

• swelling
• bruising over bone
• deformity
• pain (worse on movement or when pressure applied)

Investigations

• platelet concentrates
• x ray
• MRI
• bone scan

Question 5

How do fractures heal?

Answer 5

Stage 1: inflammation.
Begins immediately. Haematoma and fibrin clot. Cells include platelets, PMNs, neutrophils, monocytes, macrophages and byproducts of cell death - lysosomal enzymes. Fibroblasts. Mesenchymal and osteoprogenitor cells induce cells from muscle and soft tissues. Angiogenesis occurs.

Stage 2: soft callus.
Begins when pain and swelling subside, lasts until bony fragments are United by cartilage or fibrous tissue. Gives some stability of the fracture. However angulation can still occur. Continued increase in vascularity.

Stage 3: hard callus.
Conversion of cartilage to woven bone. Increasing rigidity.

Stage 4: bone remodelling.
Woven bone converted to lamellar bone. Medullary canal is reconstituted. Bone response to loading characteristics Wolffs Law.

Question 6

What are the complications of fractures?

Answer 6

Short term: vascular damage, damage to other organs, soft tissue damage, haemarthrosis, compartment syndrome, infection, shock, thromboembolism, fracture blisters

Long term: delayed union, non union, delayed healing, growth disturbance, nerve damage, decreased strength and increased discomfort, joint problems, anxiety and depression, activity restriction