Fracture Mechanics

Question 1

Bone Properties

Answer 1

Capacity to regenerate

Remodel in response to stress (Wolff’s Law)

Question 2

Forces on fractures

Answer 2

Tension, compression, shear, bending, torsion

Question 3

Strength of bone dependent on

Answer 3

Material properties, structural, orientation of load applied, rate of load applied

Question 4

Increased kinetic energy

Answer 4

trash the soft tissues too

Question 5

Incomplete fractures

Answer 5

Greenstick, fissure and depression fractures. No displacement of bone

Question 6

Complete fractures

Answer 6

Transverse, oblique, spiral, comminuted, segmental, and compression fractures

Question 7

Transverse fractures

Answer 7

Result of bending forces

Question 8

Oblique fractures

Answer 8

Bending and axial forces

Question 9

Spiral fractures

Answer 9

Torsional forces

Question 10

Segmental fractures

Answer 10

Fractures lines to not communicate

Question 11

Comminuted

Answer 11

Result of high energy trauma

Question 12

Type 1 fracture

Answer 12

Clean soft tissue laceration of <1cm

Question 13

Type 2 fracture

Answer 13

Soft tissue laceration of >1cm; mild trauma. No flaps or avulsion

Question 14

Type 3a Fracture

Answer 14

Soft tissue available for wound coverage despite vast laceration. Flaps or high energy trauma

Question 15

Type 3b Fracture

Answer 15

Extensive soft tissue injury loss, periosteum stripped and bone exposed

Question 16

Type 3c Fracture

Answer 16

Arterial supple to the distal limb damaged, arterial repair indicated

Question 17

Fracture etiology extrinsic forces v intrinsic

Answer 17

direct v indirect

Physiologic, pathologic, stress

Question 18

Describing fractures

Answer 18

Open or closed, configuration, location, right or left, bone, displacement

Question 19

Secondary bone healing

Answer 19

Inflammatory phase, reparative phase, remodeling phase. Strength dependent on callus formation
Granulation to fibrocartilage to bone

Question 20

Primary bone healing

Answer 20

Requires rigid fixation. Associated with minimal callus formation. Contact healing: direct apposition. Gap healing: gaps <1mm

Question 21

Fracture healing

Answer 21

Dependent on age of animal and location and type of fracture. Callus expected to be evident in 2-4 weeks. Fracture line may initially widen. Fracture segments and fragments remodel

Question 22

Accelerate healing

Answer 22

Reduce better.
Bone graft- greater trochanter- humerous
Osteogenic direct, osteoinduction, osteoconduction