Lecture 5

Question 1

Transverse fractures?

Answer 1

• There is complete separation, and the fracture is perpendicular to the length of the bone
• May be caused by a shear force or side impact

Question 2

Oblique fractures?

Answer 2

• The fracture line runs diagonally along the length of the bone
• May occur as a result of bending or twisting (torsion)
• Usually seen in shaft of a long bone, such as the femur, tibia or humerus

Question 3

Spiral fractures?

Answer 3

• The bone has been twisted apart
• Often this type of fracture will result in sharp bone edges which can penetrate muscle or other tissue
• Occurs following some rotational action (torque) on the bone

Question 4

Compression fractures?

Answer 4

• Occurs in the vertebral body
• Vertebrae crush under the weight of the body
• Osteoporosis is the most common cause of this type of fracture

Question 5

Stress fractures?

Answer 5

• A fracture which has not resulted in a complete break of the bone. However, if undetected this could happen
• Is caused by the pull of muscles without the intervention of trauma or extreme weight-bearing
• Usually occurs in the lower extremities in athletes

Question 6

Greenstick fractures?

Answer 6

• When a bone bends and cracks, instead of breaking completely
• Most commonly occurs in children because their bones are softer and more flexible than the bones of adults
• Arises due to the fact that bone is stronger under compression

Question 7

What is the simplest form of bone repair?

Answer 7

To re-align the bone and allow natural bone growth to cause the broken bone to fuse together
(splints, casts, etc.)

Question 8

What are other ways to repair more severe breaks?

Answer 8

• Metal plates and screws can be used to hold the broken bones in place
• External fixators can be used to hold broken bones in place until natural growth fixes the bone
• Tissue engineered biomaterials can stimulate growth

Question 9

What is osteoporosis?

Answer 9

• A disease which compromises the matrix structure of bone, significantly reducing its mechanical strength
• Compromises the trabecular structure in the bone

Question 10

What is the typical lifetime of a hip replacement?

Answer 10

10-12 years, after which it has to be replaced

Question 11

What happens to a hip replacement that causes it to need to be replaced?

Answer 11

Loosening, a break or dislocation