Principles of Tendon and Ligament Biology

Question 1

What are tendons and liagements

Answer 1

Dense, fibrous connective tissue

Question 2

What is the role of Type 1 collagen

Answer 2

It provides high tensile strength

Question 3

What does the fact that tendons and liagements are viscoelastic mean

Answer 3

They respond a different way depending on the force/ speed of movement

Question 4

What does the crimping in tendon tissue mean

Answer 4

You are able to apply a lot of stress to a tendon without it rupturing

Question 5

In tendons and ligaments what provides a failsafe mechanism

Answer 5

Fasciles

Question 6

What does the fact that tendons and ligaments are not passive structures mean

Answer 6

They respond to mechanical loading and exercise

Question 7

What are living cells in tendons called

Answer 7

Fibrblasts

Question 8

What do fibroblasts do

Answer 8

Look after and produce ECM

Question 9

How do fibroblasts communcate

Answer 9

Via gap junctions

Question 10

How to fibroblasts detect and respond to mechanical loading

Answer 10

By increasing the amount of collagen

Question 11

Why do athletes have larger tendons

Answer 11

Because of their constant, long-term commitment

Question 12

What happens to tendons in cases of immobalisation

Answer 12

They become thinner and weaker. In long term recovery form casting it is essential in the beginning to improve motility before exerting force in order to regain controlled passive movement.

Question 13

Why are tendons an essential component of the musculoskeletal system

Answer 13

They transfer force from muscle to bone to generate movement

Question 14

Where do tendons attach

Answer 14

They extend from myotendinous junction (MTJ) to enthesis (osteotendinous junction)

Question 15

What do tendons do

Answer 15

Enable the muscle bulk to be distant from the site of action, reduce bulk and occupy narrow spaces

Question 16

What kind of movement do tendons enable

Answer 16

Proportionate movement

Question 17

What does tendons reinforcing/ replacing joint capsules do

Answer 17

Help to stabilise joints in the shoulder and proximal interphalangeal joints

Question 18

What does the fact that tendons have an elastic nature mean

Answer 18

They can harness energy in locomotion and add this energy to subsequent action meaning that movement is economical

Question 19

Where do ligaments attach

Answer 19

Bone to bone (one enthesis to another)

Question 20

What do ligaments do

Answer 20

Guide and limit joint movements by limiting allowable movements and prohibiting unwanted movements

Question 21

What can ligaments be

Answer 21

Separate, accessory or capsule thickenings. Sometimes ligaments become part of the joint capsule

Question 22

Where have proproception-mechanoreceptors been identified

Answer 22

In the shoulder, knee and ankle joints (and overlying cutaneous layer)

Question 23

What hold tendons in place

Answer 23

Retinaculae

Question 24

What do retinacular in digits do and what happens if they rupure

Answer 24

Ensure the tendon runs close to the bone, if they ruprue bowstringing occurs.

Question 25

What makes up myotendinous junctions and what do they do

Answer 25

Made up by ligaments. They transfer force from the muscle to the tendon.

Question 26

What is the key feature of the end of a muscle before it attaches it connective tissue

Answer 26

It is high invaginated

Question 27

What does invagination do

Answer 27

Increase the surface area for attachment

Question 28

Why are myotendious junctions highly adapted to transfre force

Answer 28

The muscle is high invaginated before it attaches to the connective tissue

Question 29

What are muscles that cross 2 joints called

Answer 29

Biarticular

Question 30

What are muscles tears the occurs at the MTJ typical of

Answer 30

Eccentric contraction

Question 31

What shape are flexor tendons and why

Answer 31

Round/oval which is characteristic of tendons in the palm of the hand to enable tendons to glide smoothly resulting in less friction

Question 32

What shape are extensor tendons and why

Answer 32

Flattened to prevent sublaxation (means tendons go over the top of the knuckle when you make a fist and don't fall out of place

Question 33

What is present between tendons

Answer 33

Connective tissue

Question 34

What are the clinical characteristic of chronic tendinopathy

Answer 34

> 3 months, pain, impaired activity and stiffness, increased tendon thickness, may lead to partial/ total rupture, tendinitis-inflammation

Question 35

Histological observations during surgical interventions in chronic tendinopathy

Answer 35

No inflammatory cells, instead get disordered collagen and fatty deposits resulting in degeneration. During the initial stages inflammation may be present

Question 36

In scans what does a healthy tendon look like

Answer 36

Bright white

Question 37

In scans what does a pathological tendon look like

Answer 37

Brown and thickened or yellow due to calcification

Question 38

What is used to test for a torn Achilles tendon and what means the Achilles is ruptured

Answer 38

The Thompson test. No movement= Achilles ruptured

Question 39

Describe tendon rupture

Answer 39

Spontaneous rupture is most commonly observed during sporting activities, especially during eccentric contraction. Before a rupture a patient is asymptomatic. During a rupture there is pain, sudden popping, bruising and a little bleeding.

Question 40

Under histological examination what do most tendons sow

Answer 40

Degeneration within several cm above and below the rupture

Question 41

What are entheses

Answer 41

Attachments of tendons or ligaments to bone

Question 42

What are entheses prone to

Answer 42

Pathology

Question 43

What are examples of enthesopathies

Answer 43

Tennis elbow, heel spurs, Os-good Schlatters disease, spondylarthropathies

Question 44

What is Os-good Schlatters disease

Answer 44

Inflammation at the attachment site of the tibia

Question 45

What is ankylosing spondylitis

Answer 45

Ossification of enthesis resulting in decreased movement (back, rib expansion, neck) and effects the vertebral column as well as other regions resulting in pain and limited movement

Question 46

What is the primary target organ of ankylosing spondylitis

Answer 46

Enthesis

Question 47

Who does ankylosing spondylitis effect

Answer 47

Males when they are around 25 years old

Question 48

What are the two types of entheses

Answer 48

Fibrous and fibrocartilaginous

Question 49

What are fibrocartilaginous entheses

Answer 49

Where the tendon attaches to the end of a long bone or short bone of the hands or feet

Question 50

Which type of entheses are much more prone to pathologies

Answer 50

Fibricartilaginous

Question 51

What is the function of fibrocartilaginous entheses

Answer 51

They enable gradual bending meaning that the fiber isn't focused at the tissue interface resulting in decreased fraying and dissapation of stress away from the tissue interface

Question 52

What is the smooth front of a fibrocartilaginous enthesis made of and what is its function

Answer 52

It is a calcium front and the smooth front strengthens and prevents movement.

Question 53

What does the fact that the fibrocartilaginous enthesis is high invaginated mean

Answer 53

`The surface area is increased and therefore a stronger attachment site is formed

Question 54

What does the strength of the fibrocartilaginous enthesis mean

Answer 54

You are more likely for the bone attachment to break off from the rest of the bone than the fibrocartilaginous enthesis to rupture

Question 55

Why does degeneration of the fibrocartilaginous enthesis occur in golfers/ tennis elbow

Answer 55

It is due to repeated loading

Question 56

What are tendons called when they change the direction of the muscle they pull

Answer 56

'wrap around regions' or 'gliding regions'

Question 57

What do the wrap around pulleys of tendons do

Answer 57

Generate movement

Question 58

What is an important functional adaptation that takes place in 'wrap around regions'

Answer 58

The area adjacent to the bone becomes compressed and therefore cartilaginous type tissue which resists compression (tendon undergoes metaplasia- changing tissue type)

Question 59

Why are tendons in the foot a common injury site in runners

Answer 59

Due to degeneration of tendons