Soft Tissue Healing

Question 1

Definition of sprain

Answer 1

A sprain is a stretch or tear of a ligament. It’s the fibrous band of connective tissue that joins the end of one bone with another. Ligaments stabilise and support the body’s joints.

Question 2

What are the 4 grades of sprain

Answer 2

Normal
Grade 1 sprain - stretching small tears
Grade 2 sprain - larger but incomplete tear
Grade 3 sprain - complete tear

Question 3

Definition of strain

Answer 3

Muscle or tendon injury which involves over contracting or lengthening a muscle causing tearing of collagen
Internal - contraction or lengthening
External - e.g. kicked

Question 4

Factors that cause tissue damage

Answer 4

Injury - physical, thermal, radiational, electrical, chemical
Infection - viruses, bacteria fungi, protozoa
Infarcation - myocardial infarct
Immune reactions - foreign protein hypersensitivity and auto immunity

Question 5

2 Types of body tissues

Answer 5

Parenchymal tissue - functioning cells of organs for example: neuronal (brain) tissue, epithelial (skin) tissue, cardiac myocyte (heart) tissue and hepatocyte (liver) tissue

Stromal (interstitial) tissue - supporting connective tissues, contains many cell types including fibroblasts, involved with blood vessels and nerve and never endings

Question 6

What are the 3 types of tissue healing

Answer 6

Resolution - rapid healing of mild injury, epithelial cells slough and regenerate without incident

Tissue regeneration - specialised tissue is replaced by the proliferation of surrounding undamaged specialised cells and injured tissues are repaired with parenchyma

Connective tissue repair (replacement) - lost tissue is replaced by granulation tissue which matures to form a scar tissue

Question 7

What are 3 types of cell which have the ability to regenerate

Answer 7

Labile cells - constant turn over, can be skin cells

Stable cells - usually stop growing once growth stops, can be liver. Requires a supportive framework if damage occurs

Fixed (permanent) nom dividing cells - cannot undergo mitosis, can be nerve, muscle and cardiac. Tissue repair leaves a scar

Question 8

What are the stages for connective tissue repair

Answer 8

Bleeding - 6-8 hrs
Inflammation - 2-3 weeks
Proliferation - days to months
Remodelling - weeks to months

Question 9

Classify bleeding phase

Answer 9

Occurs following injury 
Relatively short lived 
More vascular tissue (e.g. muscle) will bleed for longer 
Other tissues (e.g. ligaments) bleed less volume and duration 
Average is 4-6 hrs, but some continue to bleed longer

Question 10

Classify the inflammatory phase

Answer 10

Changes in blood flow - exudation of protein rich fluid (oedema)
Leukocyte emigration
Phagocytosis
Lymphatic drainage

Question 11

Classify the proliferative phase

Answer 11

24-48 hrs after injury fibroblasts, macrophages and blood vessels proliferate to form granulation tissue
Angiogenesis occurs with development of capillary buds
Capillary network is leaky
WBC and plasma proteins leak into tissue

Question 12

Classify the remodelling/maturation phase

Answer 12

Begins at 3 weeks and can last up to 2 years.
Continuous remodelling of scar tissue
- collagen (type 1) synthesis by fibroblasts
- simultaneous lysis by collagenase enzymes
Physical stress is an important factor in this stage

Question 13

What are the factors that affect wound healing

Answer 13

Nature of injury, site of injury, temperature, drugs, prolonged inflammation, movement (stress), malnutrition, blood flow and oxygen delivery, infection, wound separation, foreign bodies, age, adhesion to bone/tissues

Question 14

What are the complications of tissue repair

Answer 14

Infection - invasion by microorganisms
Ulceration - circumscribed, open, crater like lesions of the skin or mucous membranes
Dehiscence - deficient scar formation, wound separates
Keloid development - hypertrophic scars, excessive collagen production
Adhesions - fibrous connections between cavities and tissues