Musculoskeletal Growth/Injury and Repair - Ligament and Tendon

Question 1

What are ligaments? Function?

Answer 1

• Dense bands of collagenous tissue, some of which are just condensations of joint capsules
• Anchored to bone at each end, provide joint stability through ROM

Question 2

What are the components of a ligament?

Answer 2

• Collagen fibres (type 1)
• Fibroblasts
• Sensory fibres (proprioception / stretch / sensory)
• Vessels at surface

Question 3

What are the differences in composition between tendons and ligaments?

Answer 3

Ligaments are more compliant due to:

• lower percentage of collagen
• Higher percentage of proteoglycans and water
• Less organized collagen fibres
• Ligaments also have rounder fibroblasts

Question 4

How does the resistance of ligaments vary with rate of force loading on them?

Answer 4

• Ligaments are stronger under faster rates of loading

Question 5

What is a common complication of ligament ruptures? What is one of the commonest areas for ligament ruptures in the body?

Answer 5

• Loss of proprioception

- Ankle joint is very susceptible

Question 6

What are the phases of ligament healing?

Answer 6

Haemorrhagic

Proliferative

Remodelling

Question 7

What occurs in the haemorrhagic phase of ligament healing?

Answer 7

• Begins with large haematoma that is gradually resorbed

- Then triggers a hypertrophic vascular response and the blood is replaced with a heavy cellular infiltrate

Question 8

What occurs in the Proliferative phase of ligament healing?

Answer 8

Production of scar tissue and laying down of disorganized collagenous connective tissue

Question 9

What occurs in the Remodelling phase of ligament healing?

Answer 9

The collagenous matrix that has been laid down becomes slightly more organized and ligament-like

• Major differences in architecture, composition and function still persist though

Question 10

Which patients are often given conservative (non-operative) treatment for tendon ruptures? What are some examples of conservative management?

Answer 10

Patients with partial or stable ligament injuries, or patients that are poor candidates for surgery

• Conservative management focuses on joint immobilization, so soft tissue braces up to casts etc.

Question 11

Which patients tend to be given operative treatment for ligament injuries?

Answer 11

Unstable injuries (ACL), athletes and people with mulitple ligaments injured

Question 12

What are some options for operative ligament rupture treatment?

Answer 12

• Direct repair
• Direct repair + augmentation (add tape to ligament to strengthen it)
• Ligament replacement (usually done with some tendon often taken from hamstrings & then attached to bones)

Question 13

Via what structure do tendons attach to bone?

Answer 13

Sharpey’s fibres

Question 14

Describe the composition of tendons

Answer 14

Composed mostly of tenocytes and collagen fibres (type 1)

longitudinal arrangement of cells

surrounded by tendon sheath

Question 15

Describe the structural arrangement of tendons

Answer 15

• Long, narrow spiralling collagen bundles covered by endotenon
• Collagen bundles group to form fascicles which are covered by paratenon
• Fascicles group into tendons which are covered by epitenon

Question 16

Describe the structure of the blood supply of tendons?

Answer 16

• Blood vessels located in the paratenon

- Blood vessels enter the tendons via vincula (vinculum)

Question 17

How is the tendon sheath connected to the tendon in the flexors of the fingers? How does the tendon sheath help supply nutrition to the tendon?

Answer 17

• Connected via a vinculum
• Vincula contain blood vessels
• Often there is also synovial lining and fluid associated with the tendon sheath providing nutrition

Question 18

In the fingers, how are the tendons associated with the bone?

Answer 18

There are thickenings of the tendon sheath that form strong annular pulleys that keep the tendon closely associated to the bone

• Prevents bow-stringing of tendon between bone and carpal tunnel

Question 19

How does immobilization affect tendons?

Answer 19

Immobility reduces water content and glycosaminoglycan concentration

Also reduces strength

Question 20

What happens during tendon degeneration? How may tendon degeneration present? Where does it commonly occur?

Answer 20

Intrasubstance mucoid degeneration

• Presents with swelling +/- pain or tenderness
• Occurs in achilles tendon

Question 21

What is de quervain’s tendinitis? How does it present? Tests for diagnosis?

Answer 21

• Inflammation of EBP & APL at radial aspect of wrist
• Presents as swollen, tender +/- hot
• Positive Finklestein’s test

Question 22

What is enthesiopathy? What is a common place for this to occur?

Answer 22

Inflammation at the insertion of the tendon onto the bone (more usually at the side of muscle origin)

At the elbow (tennis elbow)

(can also occur in ligaments - plantar fasciitis)

Question 23

What is traction apophysitis? Common example? How does it progress?

Answer 23

• Damage to the apophysis of a bone that has not yet reached skeletal maturity (still have growth plates) caused by excessive pull by a tendon (exercise)
• Osgood-Schlatter’s disease (where patella tendon inserts onto tibial tuberosity)
• Pain resolves with rest, or as skeleton reaches maturity

Question 24

What is tendon avulsion? Where does it commonly occur?

Answer 24

Pulling off of a tendon (load exceeds failure strength)

• May occur +/- a fragment of the bone the tendon attaches to

Commonly occurs at distal phalanx and in biceps

Question 25

How is tendon avulsion treated?

Answer 25

If the tendon does not retract (finger) treatment can be conservative - splints If the tendon retracts surgery is needed: - reattach tendon through bone - or fix bone fragment back on

Question 26

What causes instrasubstance ruptures of tendons? Where do they commonly occur?

Answer 26

- Load exceeds the failure strength, often occurs in achilles tendon In achilles tendon, mechanism of rupture: - pushing off forefoot while extending knee - unexpected dorsiflexion of ankle - violent dorsiflexion of plantar flexed foot

Question 27

What are some clinical examination tests for achilles tendon rupture?

Answer 27

- Feel for palpable tendon gap in ruptured tendon (not always present) - Simmond's test: patient lying prone, squeeze the gastrocnemius and the patients foot should plantar flex (positive if doesn't flex - rupture)

Question 28

What is a musculotendinous junction tear? How does it present? How are they usually treated?

Answer 28

- Tear at the junction between muscle belly and tendon - Presents with severe pain + swelling - Usually conservative treatment due to tears mostly being partial

Question 29

When would tendon ruptures tend to be treated conservatively?

Answer 29

When the two ends of the tendon can be opposed (put close together - met up)

Question 30

When would tendon ruptures be treated operatively?

Answer 30

- When the ends of the tendon cannot be opposed - In highly active people - When there is a high risk of re-rupture

Question 31

What is the most common place for tendon laceration / incision? How are these treated?

Answer 31

- In the fingers and hands (FDS & FDP) | - Need to be surgically repaired early (if left untreated may need grafts to re-attach tendon ends)