What are the 3 phases of tissue healing?
Acute (inflammatory), Repair, Remodeling.
Duration of the acute (inflammatory) phase?
First 3–4 days.
Main signs/symptoms of acute phase?
Pain, spasm, swelling, redness (erythema), ↑ temperature.
Purpose of acute phase inflammation?
Protect, localize, rid problematic agents, prepare for healing.
What cells are attracted to the area during acute phase edema?
Leukocytes.
What is phagocytosis?
Leukocytes break down and remove injury debris.
What is secondary injury?
Tissue death from hypoxia, ischemia, or free radicals in surrounding uninjured tissue.
Duration of the repair phase?
48 hours – 6 weeks.
What is formed in the repair phase?
Immature scar tissue.
Characteristics of scar tissue in repair phase?
Random, unorganized, weak, easily re-injured.
Clinical sign that repair phase has begun?
Swelling/pain decreases and function begins to return.
When does collagen begin forming in scar tissue?
During repair phase.
Duration of remodeling phase?
Can last up to 1 year.
What happens during the remodeling phase?
Scar tissue matures, reorganizes, realigns along stress lines, becomes stronger.
What type of collagen is most common in remodeling?
Type I collagen.
How long until firm scar tissue is in place?
About 3 weeks.
What is the risk if remodeling phase is rushed?
Excess scar tissue, poor alignment, prolonged healing.
Define Wolff’s Law.
Tissue remodels and realigns along the lines of tensile stress placed on it.
Clinical implication of Wolff’s Law?
Proper stress promotes healing and function.
What happens if stress is applied too early or too much?
Excess scar tissue, poor alignment, extended healing.
What happens if there is too much immobilization/rest?
Weak scar tissue, poor strength, poor alignment.
When does acute inflammation become subacute?
If it lasts longer than 1 month.
When does it become chronic?
Longer than 1 month and not resolving.
Causes of chronic inflammation?
Repeated micro/macro trauma, improper treatment, premature return to activity.
