Connective Tissue Part 3 Injury and Repair Flashcards
What are five types of tendon injuries?
- peritendinitis
- tendinitis
- tendinosis
- chronic tendinitis
- Rupture
Three phases of tendon healing?
- inflammatory phase
- reparative or collagen producing phase
- remodeling phase/maturation phase
How does scar tissue lay in comparison to previous collagen fibers?
perpendicular, remodeling is dependent on stress
What are the two roles of fibroblasts as they migrate to the wound?
-reparative and reabsorptive
what happens if you have excessive collagen synthesis?
excessive scar tissue and adhesions that can restrict mobility
when is tensile strength of a healing tendon sufficient for strong contraction with out disruption of healing?
4-5 weeks
in regards to tendon healing, what does immobilization do?
- reduces collagen synthesis (weaker tendon)
- decreased nutrition to tissue form synovial fluid
- adhesion formation
- essential to prevent rupture in early stages
when letting a tendon heal you should immobilize and then?
gradually increase controlled mobilization
what is collagen fibers surrounded by CT, connects bone to bone
ligaments
what fibers are collagen fibers that penetrate bone matrix, bind to periosteum to bone and reinforce tendinous/ligamentous insertions?
Sharpeys Fibers
what is the main structural support for joint stability?
ligaments
where do ligaments get their blood?
arterial plexuses
what is the benefit of sensory receptors in ligaments/joints?
proprioceptive feedback and kinesthetic awareness
history of trauma, point tenderness, and joint effusion are characteristics of what type of injury?
Ligament
How many grades of ligaments sprains are there?
3
- mild
- moderate
- severe
Grade 1 ligament sprain
mild, no increased laxity/instability, painful
Grade 2 ligament sprain
moderate, slight laxity/instability, marked swelling/pain
Grade 3 ligament sprain
severe, disruption of ligament with gross instability, marked swelling, significant pain
What is the most common tear of a ligament?
mid substance tear during fast loading
What is the least common tear of ligament?
insertion point
What type of ligament tear occurs with slow loading mostly in people over 50 years old?
avulsion of bone
How long is the proliferation/repair stage of ligament healing?
48-6wks
New capillary growth, fibroblastic activity, formation of fibrin close, production of collagen/ECM, fibrin clot, and collagen randomly arranged is what stage of healing in a ligament?
proliferation/repair
how long is the remodeling/maturation stage of ligament healing??
6 wks to 24+ months
collagen organizes along lines of stress, increases strength of ligament, and collagen shifts from type III to type I
Remodeling/Maturation
two types of injury to cartilage?
- loss of matrix macromolecules with out damage to cells or matrix
- mechanical injury
three types of mechanical injury in cartilage?
- trauma
- penetrating injuries
- frictional abrasion
how soon is the fibrin clot in cartilage repair?
wishing 48 hours
When do fibroblasts and collagen type I replace the fibrin clot in cartilage repair?
+5 days
When is matrix formation in cartilage repair?
2 weeks
After 2 months repair is complete but
the matrix is lacking
what type of injury is it when there is death of matrix and cells, tearing of periosteum, endosteum and capillaries, and fragments?
Fracture Healing, Bone Repair
Describe the repair process of bone healing?
- localized hematoma (impaction, induction, inflammation)
- internal callus formation (set callus-proliferative)
- cementing bone, cartilage layer, proliferative osteogenic surface layer
- external callus (hard)
- remodling
what is wolfs law
stresses applied to bone will alter the structure of the bone
what is the force per cross sectional area
stress
what type stress is stretched perpendicular to cross section
tensile stress
stress of squeezing force perpendicular to cross section
compressive stress
force parallel to cross section
shear stress
what is the percent change in length
strain
What are two time dependent propteries of joints?
Force Relaxation and Creep
at a fixed length, the drop in force measured over time
Force Relaxation
constant foce, tissue gradually lengthens-due to rearrangement of structures in ECM
Creep
Factos affecting biomechanics propteries
age pregnancy non-steriodal drugs steroids exercise immobilization stiffness viscoelasticity
Matrix changes when you immobilize a tendon or ligament?
- decreased water
- decreased GAGs
- increased tissue metabolism
- increased collagen turnover
- increased immature collagen
- increased cross linkages
What happens when cartilage is immobilized
- adherence to fatty CT
- atrophy
- pressure necrosis and cartilage
- softening of articular cartilage
- loss of ECM proteoglycans
What happens when immobilizing a muscle in lengthened position?
- fibers lengthen
- more sarcomeres
- shorter sarcomeres
- increased actin/myosin
- lengthened tendon
- length/tension curves right
what happens when you immobilize a muscle in shortened position?
- fibers shorten
- less sarcomeres
- longer sarcomeres
- decreased actin/myosin
- shortened tendon
- length tension curves left
Types of stretch?
- stretch
- elastic stretch
- plastic stretch
- viscoelastic
linear deformation that increases length
stretch
tissues return to pervious length, short term deformation
elastic stretch
increased length maintained without sustaining force-permanent deformation
plastic stretch
substance with bother plastic and elastic stretch
viscoelastic
Stretching implications
- activation of muscle spindle-stretch reflex
- use of GTO to facilitate relaxation and increase stretch
- stretch plastic not elastic
