Fractures and bone healing

Question 1

What is a closed and open fracture?

Answer 1

Closed Bone fragments do not pierce skin Open/compound Bone fragments pierce skin

Question 2

Label this image

Answer 2

Answers

Question 3

What kind of frcature is this? How is it usually caused?

Answer 3

Transverse fracture

•Usually caused by directly applied force to fracture site

Question 4

What kind of fracture is shown here? How is it often caused?

Answer 4

Spiral or oblique

•Caused by violence transmitted through limb from a distance (twisting movements)

Question 5

What type of fracture is shown here?

Answer 5

Transverse fracture

Question 6

What type of fracture is shown here? How is it most often caused?

Answer 6

Compression fracture

Fracture in cancellous bone: result of compression (osteoporosis)

Question 7

At what age does a crush fracture occur? What causes it?

Answer 7

•Between 30 and 80 years of age,

–Elasticity of trabecular bone decreases by 64%

–Strength decreases by 68%

–Toughness decreases by 70%

Question 8

What causes burst fracture? Where are they most likley to occure?

Answer 8

Cuased by strong direct pressure

Occurs in short bones e.g. vertebra - •Most common at thoracic/lumbar junction

Question 9

What kind of fracture is this?

Answer 9

Burst fracture

Question 10

What kind of fracture does this image show? How is this fracture often caused?

Answer 10

Avulsion fracture

• Caused by traction
• Bony fragment usually torn off by a tendon or ligament.

Question 11

What type of fracture is this? How is it caused?

Answer 11

Fracture dislocation/subluxation

•Fracture involves a joint: results in mal-alignment of joint surfaces

Question 12

What type of fracture is shown in this image? How is it caused?

Answer 12

Impacted fracture

•Bone fragments are impacted (forced, pushed) into each other

Question 13

What type of fracture is shown in this image?

Answer 13

Fracture dislocation/subluxation

Question 14

What type of fracture is shown in tis image? How is it caused?

Answer 14

Comminuted fracture

•Two or more bone pieces - high energy trauma

Question 15

What type of fracture is this?

Answer 15

Impacted fracture

Question 16

What type of fracture is shown here? How is it often caused?

Answer 16

• Abnormal stress on normal bone (fatigue fracture)
• or normal stress on abnormal bone (insufficiency fracture)

Question 17

Name and describe the 2 different types of stress fractures

Answer 17

• Abnormal stress on normal bone (fatigue fracture)
• or normal stress on abnormal bone (insufficiency fracture)

Question 18

How can an X ray be used to identify stress fractures?

Answer 18

Periosteal reaction on plain film. Bone scintigraphy

becomes positive at same time or sooner than plain films.

Question 19

What type of fracture is this?

Question 20

What type of fracture is shown in this image and how is it often caused?

Answer 20

Torus fracture

•Extremely common injuries to children

–Softer bones

• Axial loading causing trabecular compression
• One side of the bone may buckle
• Bulging of the cortex

Heal very quickly

Question 21

What type of fracture is this and how is it usually caused?

Answer 21

Green stick fracture

•Occurs in children: bones soft and bend without fracturing completely

Question 22

What kind of fracture can interfer with growth?

Answer 22

Fractures of the epiphyseal growth plate

Question 23

What kind of fracture is this?

Answer 23

Fractures of the epiphyseal growth plate

Question 24

What kind of fracture is this?

Answer 24

Torus fracture

Question 25

Describe the different types of Epiphyseal growth plate fractures

Answer 25

Type 1- Complete physeal fractures

Type 2- physeal frcature that extends to the metaphysis- so a chip fracture in the metaphysis

Type 3- physeal fracture that extends through the epiphysis

Type 4- Physeal fracture plus metaphyseal and epiphyseal fracture

Type 5- Compression fracture of the growth plate

Question 26

Describe the mechanisms involved in bone healing

Answer 26

Step 1- fracture hematoma

–blood from broken vessels forms a clot

–6-8 hours after injury

–Swelling and inflammation occurs at fracture site

Step 2- Fibrocartilaginous callus

–new capillaries organise fracture hematoma into granulation tissue - ‘procallus’

–Fibroblasts and osteogenic cells invade procallus and make collagen fibres

–Chondroblasts begin to produce fibrocatilage

lasts about 3 weeks

Step 3- Inflammatory, granulation and soft callus

• Inflammatory cells appear
• Resorption of clot as new capillaries form
• Fibroblasts enter and differentiate into chondrocytes
• Chondrocytes produce collagen that bridges fracture site - cartilage and trabecular bone is laid down

Step 4 - Bony callus

after 3 weeks and lasts about 3-4 months

–osteoblasts make woven bone.

Step 5- Bone remodelling

–Osteoclasts remodel woven bone into compact bone and trabecular bone

–Often no trace of fracture line on X-rays.