Soft Tissue

Question 1

Phases of soft tissue injury recovery.

Answer 1

1. bleeding - clot formation, increase/decrease swelling
2. inflammatory - critical period 2hr-6days. First 72h is vital, poor management = suboptimal outcomes
3. proliferative - new tissue / angiogenesis
4. maturation - scar formation, remodelling, alignment

All phases overlap and interact to achieve the healing of damaged structures

Question 2

Why is inflammation important?

Answer 2

to start initial adaptation/recovery –> necessary part of healing

process that helps with repair of tissue
- dynamic cascade of cytologic and histologic reactions in blood vessels and adjacent tissues
- macrophages (WBC) provide inflammatory response

Question 3

What happens during initial bleed?

Answer 3

Body wants homeostasis, platelets arrive and form a “plug” to coagulate/block further blood loss. Platelets help with fibrin reinforcement

Haemostasis: platelet plug coagulation / fibrin reinforcement

Platelet (derived from growth factor) promotes tissue healing through tissue regeneration

Question 4

What happens when damaged cells release chemokines during the initial phase?

Answer 4

• activate local Mast Cells that degranulate to release histamine.
• histamine interacts/increases vessel permeability via vasodilation.
• as vessel size increases/dilates, endothelial retraction simultaneously occurs to increase permeability.
• Bradykinins also helps with vasodilation while prostaglandins assist with pain signalling to nervous system.

Question 5

What happens after the initial phase/response to soft tissue injuries?

Answer 5

extravasation of polymorphonuclear leukocytes (the neutrophils - remove damaged tissue) occurs. They are pushed outside the vessels into the interstitial tissues.

Other substances come out such as albumin (attracts fluid = cause swelling).

The monocytes also migrate to injury site (along with macrophages) that ingest damage tissues and foreign materials for infection control.

Question 6

Provide a detailed explanation of the proliferation phase.

Answer 6

Angiogenesis - provide additional oxygenated blood.
Fibroblast collagen deposition: create provisional matrix (granulation tissue) composed mainly of collagen type III - lays down scar formation

Shortly after injury, resident tendon cells adjacent to injury site undergo apoptosis (die)

Epitenon cells (sheath surrounding tendon) close to injury proliferate, epitenon SCX+ cells migrate into scar, forming organised bridging tissue between tendon ends. S100a4+ and alphaSMA+ cells found throughout scar tissue

ECM provide proteoglycans, glycosaminoglycans, elastin, fibronectin to strengthen new scar structure

Question 7

Provide explanation of maturation phase

Answer 7

• remodelling: scar tissue remains disorganised compared to original structures (e.g. tendons and ligaments)
• dramatic decrease in both vascularity and cellularity
• adult tendons lack inherent ability to fully regenerate damaged tissue

NOTE: fibrovascular scar generated during initial healing phases is never fully replaced

Question 8

Signs and Symptoms of Inflammation

Answer 8

pain
swelling
redness
heat
loss of function

Question 9

management of soft tissue injury….

Answer 9

protect from further injury
control inflammatory exudate, pain, metabolic demands of tissue, local tissue temp.
promote collagen fibre growth
maintain CV/MSK fitness

Question 10

What are the steps of POLICE for acute management of soft tissue injuries?

Answer 10

protect, optimal loading, ice, compression, elevation

Excludes: severe pain, immediate swelling, deformity, extreme loss of function, unusual motion, noises at injury site (popping etc)

Question 11

What to avoid with acute soft tissue injuries?

Answer 11

HARM

heat: increases local metabolism/vasodilation
alcohol: may mask pain, vasodilation
running: disrupt repair processes, secondary bleeding
massage: disrupt repair processes, secondary bleeding

Question 12

Effect of protect

Answer 12

prevent further injury

Question 13

effect of optimal loading

Answer 13

oppose long-term -ve effect of immobilisation

improve capillarisation and fibre regeneration

Question 14

effect of cryotherapy (ice)

Answer 14

decrease pain and muscle spasm
- decrease local metabolism
- vasoconstriction (decrease swelling)

Question 15

effect of compression

Answer 15

increase pressure gradient in venous and lymphatic systems (facilitates drainage) to counteract oedema