Fracture Healing

Question 1

Fracture

Answer 1

Breach in continuity of bone

Question 2

When do fractures occur

Answer 2

• non-physiological loads applied to normal bone
• physiological loads applied to abnormal bome

Question 3

Describing fractures

Answer 3

Site
Pattern
Displacement/angulation
Joint involvement
Skin involvement

Question 4

Describing fractures - site

Answer 4

Bone
Part of bone - proximal, middle , distal

Question 5

Describing fractures - patterns

Answer 5

Transverse
Oblique
Spiral
Comminuted
Segmented
Avuksed
Impacted
Torus
Greenstick

Question 6

Describing fractures - displacement/angulation

Answer 6

Displacement %
Angulation of distal part

Question 7

Describing fractures - joint involvement

Answer 7

Extra-articular
Intra-articular

Question 8

Describing fractures - skin involvement

Answer 8

Open/closed

Question 9

Open fracture

Answer 9

Breach in skin
-orthopaedic emergency
- requires urgent treatment
- soft tissue injury determines outcome

Question 10

Fracture patterns unique to children

Answer 10

Epiphyses open and bone more plastic
Heal quickly
Increased deformity remodelling

Question 11

Fracture healing stages

Answer 11

Haematoma
Inflammation
Repair
Remodelling

Question 12

Fracture healing - haematoma

Answer 12

Bleeding - endosteal and periosteal vessels, muscles etc
Decreased blood flow
Periosteal stripping
Osteocyte death

Question 13

Length of haematoma stage of fracture healing

Answer 13

Hours

Question 14

Fracture healing - inflammation

Answer 14

Fibrin clot organisation - platelets rich in chemo-attractants
Neovascularisation
Cellular invasion
- haematopoeitic cells = clear debris and express repair cytokines
- osteoclasts = resorb dead bone
- mesenchymal stem cells = form osteoblasts for repair

Question 15

Function of haematopoeitic cells in inflammation

Answer 15

Clear debris
Express repair cytokines

Question 16

Function of osteoclasts in inflammation

Answer 16

Resorb dead bone

Question 17

Function of mesenchymal stem cells in inflammation

Answer 17

Differentiate into osteoblasts for bone repair

Question 18

Length of inflammation stage of fracture repair

Answer 18

Days

Question 19

Fracture healing - repair

Answer 19

Callus formation
Progressive matrix mineralisation
High vascukarity

Question 20

Callus formation

Answer 20

Fibroblasts produce fibrous tissue (high strain)
Chondroblasts form cartilage (strain <10%)
Osteoblasts form osteoid (strain <1%)

Question 21

Length of repair stage of fracture healing

Answer 21

Weeks

Question 22

Fracture healing - remodelling

Answer 22

Woven bone structure replaced by lamellar bone - osteonal remodelling
Increased bone strength
Vascularity returns to normal
Healing without scar- unique

Question 23

Length of remodelling stage of fracture repair

Answer 23

Months to years

Question 24

Principles of fracture management

Answer 24

Reduce the fracture
Immobilise the part
Rehabilitate the patient

Question 25

Types of fracture fixation

Answer 25

Slings Casts and splints Extra-medullary devices- plates and screws Intra-medullary devices- nails External fixation

Question 26

Factors the influence fracture healing - patient

Answer 26

Age Nutrition Smoking Drugs – NSAIDs, steroids

Question 27

Factors the influence fracture healing - tissue

Answer 27

Bone type: cancellous vs. cortical Bone site: upper limb vs. lower limb Vascularity / soft tissue damage Bone pathology - # in metastatic deposit does not heal infection

Question 28

Factors the influence fracture healing - treatment

Answer 28

Apposition of fragments Stability (ability to resist force without deforming) Micromotion (<1mm)

Question 29

Types of fracture complications

Answer 29

Early/late Local/general

Question 30

Early local fracture complications

Answer 30

Vessel damage Nerve damage Compartment syndrome infection

Question 31

Early general fracture complications

Answer 31

Hypovolaemic shock ARDS VTE Fat embolism

Question 32

Late local fracture complications

Answer 32

Malunion Non-union Avascular necrosis Ischaemic contractures Joint stiffness Myositis ossificans Complex regional pain syndrome Osteoarthritis

Question 33

Late general fracture complications

Answer 33

Poor mobility Functional disability and social isolation Pressure sores Disuse osteoporosis Loss of income / job

Question 34

Myositis ossificans

Answer 34

reaction to a bruise in a muscle that has been injured. During the healing of the bruise, calcium can become deposited in the bruise causing a hard bone like structure within the muscle.