Tendinopathy

Question 1

What is the composition of a tendon?

Answer 1

densely packed, slightly wavy type I collagen bundles
- held together by proteoglycans
Sparsely interdispersed tenocytes

Question 2

What is the role of a tenocyte?

Answer 2

specialist fibroblast which secretes extracellular matrix

Question 3

What is the role of the proteoglycans in a tendon?

Answer 3

hold together the collagen fibres to provide resistance to compressive forces

Question 4

What is the role of collagen in a tendon?

Answer 4

allow resistance to tensile and stretching forces

Question 5

What is the paratenon?

Answer 5

The outer layer of the tendon - reducing the friction forces

Question 6

What is the endotenon?

Answer 6

surrounds each fibre bundle to bind them together and allow gliding/sliding

Question 7

what is the epitenon?

Answer 7

Under the paratenon - surrounds the tendon

Question 8

what is the peritendon?

Answer 8

the epitenon and paratenon together surrounding the entire tendon

Question 9

What is the blood supply to a tendon?

Answer 9

sparse network within the endotenon - originates from osteotendinous and musculotendinous junctions

Question 10

What is tendinopathy?

Answer 10

overuse injury of a tendon - load placed on the tendon exceeds the tendons capacity

Question 11

What type of forces cause mid-portion Achilles tendinopathy?

Answer 11

tensile overload

Question 12

What type of forces causes insertion Achilles tendinopathy?

Answer 12

compressive overload

Question 13

How does a tendon help to transmit forces?

Answer 13

Stretch-shortening cycle - acts like a spring - energy is stored and released to allow propulsion

Question 14

What is the principle of intrinsic factors for tendinopathy?

Answer 14

When the rate of damage is greater than the rate of repair resulting in degeneration

Question 15

Examples of intrinsic risk factors for tendinopathy? (5)

Answer 15

• Older age
• Male
• weight gain
• Reduced muscle power
• Altered biomechanics (e.g. reduced DF or over-pronation)

Question 16

What are the extrinsic risk factors for tendinopathy?

Answer 16

Changes in loading - e.g. hills/increasing speed
Change in intensity or type of training
Training errors
Recent LL injury

Question 17

What are the 3 overlapping phases of tendinopathy?

Answer 17

1. Reactive tendinopathy
2. Tendon disrepair
3. Degenerative tendinopathy

Question 18

What occurs during the reactive tendinopathy phase?

Answer 18

Initial response to excessive load/compressive forces:

• non-inflammatory poliferative response
  - activation of tenocytes –> increased proteogylcans –> increased water content –> change in ground substance –> SWELLING

Question 19

Why does swelling occur in reactive tendinopathy?

Answer 19

to reduce stress by increasing cross sectional area OR to allow adaptation to compression

Question 20

What occurs during the tendon disrepair phase?

Answer 20

Tendon attempts to heal but reactive tendinopathy has not been managed - resulting in failed healing

• increased number of tenocytes –> cell metaplasia (means that the tenocytes are like chondrocytes) –> increased myofibroblasts
• neovascularisation

OVERALL, separation of collagen fibres and disorganisation of the matrix

Question 21

What occurs during the degenerative tendinopathy phase?

Answer 21

1. Areas of cell death due to tenocyte exhaustion
2. Areas form without cells - filled with matrix breakdown products
3. Large areas of disorganized matrix - filled with blood vessels ISLANDS OF DEGENERATION
4. Very little collagen is present

Question 22

What is teh clinical presentation of tendinopathy?

Answer 22

• HIghly localised pain and swelling
• Pain onset after unaccustomed training OR following trauma
• Latent pain after exercise
• Pain after rest
• Some stiffness on rising or after resting

Question 23

Why is mid-portion achilles tendinopathy more common?

Answer 23

hypovascular 2-7cm above calcaneal insertion point

Question 24

What is a subfasicle?

Answer 24

AKA primary fibre bundle - 10-20 collagen fibres bound by endotenon

Question 25

What is a fasicle?

Answer 25

AKA secondary fibre bundle - bunch of subfasicles bound by endotenon

Question 26

Whar is a tertiary fibre bundle?

Answer 26

Bunch of fasicles - bound by endotenon