Ligaments and Tendons

Question 1

Describe load elongation regions of the ligaments mechanical behaviour

Answer 1

Question 2

Describe how ligaments are attached?

Answer 2

Functionally adapted to distribute and dissipate forces by
transmitting them through fibrocartilage to bone.
Two types, direct and indirect:
Direct: Ligament-fibrocartilage-mineralized fibrocartilage-bone
Indirect: Superficial fibers: connected to periosteum
Superficial fibres (sharpey): Anchored directly to bone

Question 3

What is a tendon?

Answer 3

Connects muscle to bone and is Passive structures that surround and stabilize skeletal system

Question 4

Functions of the ligament

Answer 4

Augment mechanical stability, static constraint, guide jt motion and prevent excess motion

Question 5

How would the cross sectional area affect ligaments and tendons?

Answer 5

➢ Increased loads can be applied prior to failure
➢ Increased tissue strength
➢ Increased stiffness

Question 6

Describe the 3 types of viscoelastic responses

Answer 6

Creep: Time dependent elongation of a tissue when subjected to a constant stress.
Stress Relaxation: Time dependent decrease in applied stress required to maintain a
constant elongation
➢ Hysteresis: Energy lost within the tissue between loading and unloading, Response of tissue becomes more repeatable, Subsequent use of same force results in greater deformation

Question 7

Compare Vascularity of L and T

Answer 7

Question 8

Describe the different regions of the tendon stress-strain curve

Answer 8

Question 9

tensile strength and youngs modulus for L and T

Answer 9

Question 10

Compare ligaments and tendons under collagen %, ground substance %, organisation and orientation

Answer 10

Question 11

Describe the factors affecting biomechanical properties of L and T

Answer 11

➢ Maturation and Aging
Strength dependent on cross linking of collagen
Increased cross-link and fibre diameter post 20 years of age
Rapid decrease in diameter but increase in organisation post 60 years
➢ Pregnancy
Stiffness decreases with pregnancy
➢ Mobilization and immobilization
Loading-induced adaptation
Stronger and stiffer with exercise
Weaker with immobilization
No change in diameter, change in collagen turnover, reduced cross-links
➢ Diabetes
Increased stiffness and contracture
➢ Steroids
Inhibit collagen synthesis
Decreased stiffness and strength
➢ Non-steroidal anti-inflammatory Drugs (NSAID)
Increased collagen and strength

Question 12

Does a tendon have good tensile strength?

Answer 12

highest of any soft tissue

Question 13

describe the two ACL repair strategies: pros and cons of each

Answer 13

patella tendon graft and hamstring tendon graft
Patella - performs well, quick recovery, quick union, pain discomfort,
Hamstring - opposite

Question 14

How would longer tissue fibres affect ligaments and tendons?

Answer 14

➢ Greater fibre elongation before failure
➢ Decreased tissue stiffness
➢ Unaltered strength

Question 15

Describe the Viscoelastic behaviour of L and T

Answer 15

➢ Mech props dependent on rate of loading
➢ High rates of loading
➢ Linear region of curve steeper: Greater stiffness
➢ Store more energy, require more force to rupture
➢ Affected by movement of water
➢ Resistance to compressive force due to water trapped in proteoglycans

Question 16

describe the 6 major areas of L and T structure

Answer 16

Question 17

Functions of the tendon

Answer 17

Transmit tensile loads from muscle to bone, Dynamic restraint and enables muscle belly to be at an optimal distance from jt

Question 18

What are the tendons each muscle has?

Answer 18

Proximal: Myotendinous Junction (MTJ)
Distal: Osteotendinous Junction (OTJ)

Question 19

What is an endotendon?

Answer 19

a substance that helps to stabilise and bind the fibrils crimped in areas that may experience high stress.

Question 20

Compare the composition of L and T

Answer 20