Fracture assessment and classification

Question 1

What are you looking for in thoracic radiographs after a traumatic fracture?

Answer 1

Pulmonary contusions
Pneumothorax
Fractured ribs
Other, e.g. a ruptured diaphragm

Question 2

Orthopaedic signalment of young animals

Answer 2

More prone to physeal fractures than luxations

Question 3

Orthopaedic signalment of elderly animals

Answer 3

Pathological fracture (if after minimal trauma)

Question 4

Orthopaedic signalment differences between male and female animals

Answer 4

Male animals more prone to traumatic fractures

Question 5

Orthopaedic signalment of toy breeds

Answer 5

Prone to distal radial and ulnar fractures after minimal trauma

Question 6

Orthopaedic signalment of athletic animals e.g. grayhounds and lurchers

Answer 6

Commonly sustain fractures of accessory carpal, radial carpal, and central tarsal

Rarely seen in other dogs

Question 7

DIrect fractures

Answer 7

Occur after direct trauma. Often high energy fractures with associated extensive soft tissue.

Question 8

Indirect fractures

Answer 8

Fracture occurs some distance from the point of application of force and they tend to occur at weak points in the bone.

Fractures can be sustained after minimal trauma for example fractures of the distal radius and ulna are seen in toy breeds after a fall.

Fractures of the humeral condyle also occur in skeletally immature (3-5mth) toy breed puppies after jumping off chairs or out of owners’ arms.

Question 9

Fatigue or stress fractures

Answer 9

Occur because of accumulated microdamage to bone & may lead to eventual complete fracture.

Question 10

Pathological fractures

Answer 10

Fractures can occur after minimal trauma through abnormal bone such as neoplasms (osteosarcoma) or osteoporotic bone (nutritional secondary hyperparathyroidism).

Question 11

Muscular action fractures

Answer 11

Fractures can occur secondary to a forceful muscular contraction when the joint or limb is in a fixed position for example avulsion fractures.

Question 12

Fracture classification

Answer 12

1. cause of fracture
2. communication with external environment
3. extent of bony damage
4. number and position of fragments
5. direction of fracture lines
6. location
7. forces acting on the fracture/displacement
8. stability
9. degree of complexity and involvement of other tissues
10. age

Question 13

Golden period of treating an open fracture

Answer 13

4-6 hours after injury - can effectively be considered a closed fracture

Question 14

Typres of incomplete fractures

Answer 14

Greenstick

Fissure

Depressed

Question 15

Greenstick fractures

Answer 15

occurs in young animals with a fractured cortex on one side together with plastic deformation of the transcortex

may be stable and should heal providing disruptive forces are neutralised.

Question 16

Fissure fractures

Answer 16

often associated with comminuted fractures

can open if inappropriate fixation methods are used potentially making a fracture more complicated.

Question 17

Depression fractures

Answer 17

Usually occur in the skull and are the result of multiple fissures with anatomical displacement of a section of flat bone in the direction of the force.

Further displacement into the cavity must be resisted but anatomical reconstruction is not always necessary unless the displacement is resulting in a problem due to pressure on the underlying structures.

Question 18

Simple fracture

Answer 18

two pieces

Question 19

Comminuted fracture

Answer 19

fractures with more than two pieces and unstable.

All the fracture lines are communicating

Risk of complications is higher with this type of fracture, because of lack of vascularity at the fracture site and associated soft tissue injury.

Question 20

Segmental fractures

Answer 20

fractures with three or more fragments with fracture lines that do not meet at a common point

Question 21

Transverse fracture

Answer 21

fracture line is perpendicular to the long axis of the bone

may be able to be manipulated into position and retain axial alignment (resisting compression).

Question 22

Oblique fracture

Answer 22

fracture line is diagonal to the long axis of the bone

have little axial stability when reduced and have to be held in position artificially.

Question 23

Spiral fracture

Answer 23

the fracture curves around the bone

have little axial stability when reduced and have to be held in position artificially.

Question 24

Locations of fractures

Answer 24

Diaphyseal
a. Proximal
b. Midshaft
c. Distal

Metaphyseal

Epiphyseal (Salter Harris classification)

Condylar

Articular

Question 25

Which location of fractures heal quickest?

Answer 25

metaphyseal and epiphyseal

Question 26

Avulsion fractures

Answer 26

fractures affect a fragment of bone at the site of insertion of a muscle tendon or ligament.

fixation must counteract the strong muscular pull (eg by using pins and figure of eight tension band wire).

Question 27

Impaction fractures

Answer 27

occurs when a bony fragment (generally cortical) is forced or impacted into cancellous bone – typically occurs at the end of long bones

relatively uncommon in small animals and are often stable as a result of the interaction of the two fracture ends.
If realignment is necessary the fragments have to be disengaged and held apart by fixation to prevent shortening

Question 28

Compression fractures

Answer 28

occurs when cancellous bone collapses and compresses upon itself – usually vertebral body.

rarely subject to surgical reduction unless adjacent elements are compromised – generally heal very quickly.

Question 29

Overriding fracture

Answer 29

describe direction the most distal fragment has displaced in relation to the proximal fragment e.g. displaced proximal, cranial and medial

most fractures show overriding and one can anticipate problems at reduction if significant overriding has occurred especially in well-muscled animals and in proximal long bones.

Question 30

Stable fracture

Answer 30

those in which the fragments interlock, providing resistance to collapse

Question 31

Unstable fractures

Answer 31

fracture fragments do not interlock – type of fracture more common.

Question 32

Recent fracture

Answer 32

sharp fracture edges

Question 33

Older fractures

Answer 33

resorption of sharp edges, possibly some callus formation

Old fractures may be more difficult to reduce than fresh fractures. Old fractures include non or delayed union fractures which need special consideration.

Question 34

What are the most urgent fractures

Answer 34

Open fractures and fractures of the skull or spine - most urgent

Articular fractures and dislocations should be dealt with within 24 to 48 hours

Long bone fractures should be treated within 5-7 days

Question 35

When should intramedullary pins be used for?

Answer 35

the humerus, femur, tibia, proximal ulna, metacarpal, metatarsal and os calcaneus bones

NOT radial or mandibular fractures

Question 36

What is external skeletal fixation best used for

Answer 36

Lower limb bones

Avoid where there are large muscle masses surrounding bones

Question 37

Fixation of bones in young animals

Answer 37

the bone is relatively soft and screws will easily strip their threads, similarly in osteopenic bone screw holding is poor.

If there is underlying bone disease such as nutritional secondary hyperparathyroidism then fractures may be best treated conservatively.

Question 38

Treatment of fractures involving the joint surfaces

Answer 38

Perfect reduction of the articular surface

Using rigid internal fixation

interfragmentary compression of the fracture gap - using lag screws (+/- plates)

Early mobilisation and use of the joint is important to minimise stiffness.

Question 39

What to do if multiple limb involvement

Answer 39

the optimal or most rigid fixation method should always be chosen as the repaired fractures will be loaded to a far greater degree than in solitary injuries.