Lecture 3: Articular & Soft Tissue Injury Flashcards
what are the 3 phases of healing
inflammatory - response phase
Fibroblastic repair phase
Mature remodeling phase
What is the inflammatory response phase
occurs immediately after an injury
the damaged material initiates a response
What is the repair phase called and what happens in this phase
Fibroblastic phase
Fibroblastic cells are laid down in a matrix of collagen fibers and forming scar tissue in random manner
How can we use scar tissue to our advantage
We want to communicate to fibroblast to please do better. We can use the scar tissue to our advantage. In repair and maturation phase you are putting as much load as you can without exceeding their adaptive potential.
How long does the maturation remodeling phase take
long term process (2 years)
What happens in the maturation remodeling phase
Realigning of collagen fibers that make up the scar tissue to the tensile force to which scar is subjected
On going breakdown and synthesis of collagen occur with a steady increase in the tensile strength of the scar matrix
What are the joint stuctures
Joint capsule - outer layer Synovial Cartilage Ligaments Muscle
Does the joint capsule have a good blood supply
outer layer no
inner layer yes
Outer layer of the joint capsule is called, attaches to, vascularity, innervation, and function
Stratum fibrosum (outer layer)
◦ Attaches to periosteum
◦ Reinforced by ligamentous & musculotendinous structures –> checks movement
◦ Capsular redundancy allows full ROM (e.g. GH joint)
◦ Poorly vascularized
◦ Richly innervated by joint receptors
◦ Protects inner layer (synovium)
Inner layer of the joint capsule is called, vascularity, innervation, and function
Stratum synovium (inner layer)
◦ Highly vascularized
◦Poorly innervated ◦Synoviocytes synthesize HYALURONIC ACID
How can you reduce the viscosity of synovial fluid
rapid movement and higher temperatures
What are the components of synovial fluid
Hyaluronic acid Proteins (lubricin) Blood plasma constituents WBC's No fibrinogen or prothrombin - does not clot
What does hyaluronic acid do
contributes to viscosity
reduces friction between capsule and cartilage
What does lubricin do
contributes to cartilage to cartilage lubrication
Cartilage, what is it, what are the components and what are the two types
Connective tissue
Large fibrous component -Collagen
Small cellular component - Chondrocyte
Two types
- Hyaline cartilage
- Fibrocartilage
Hyaline cartilage is located
Articular cartilage
epiphyseal growth plate
Hyaline cartilage ECM includes
elastin
Hyaline cartilage in adults
is mostly avascular and aneural
-this means it doesn’t heal
Articular cartilage is
17 mm thick covering the articular ends of bones
Unique design of collagen fibers at right angles to subchondral bone and parallel to articular surface
Can tolerate high loads of compression
It is porous and sponge like
Is immobilization good for cartilage?
No, death to cartilage
How does articular cartilage get nutrition
synovial fluid and some from blood vessels in bony endplates
Depends on intermittent compression
- WBing
- Muscle contraction
- ROM: closed packed position
How is fibrocartilage similar and different to hyaline cartilage
Same general properties as hyaline cartilage, but greater proportion of collagen therefore it is less distensible
Where is fibrocartilage found
Found in joint spaces to increase congruency and serve as shock absorber ◦ TMJ ◦ Knee ◦ Intervertebral disc ◦ Pubic symphysis
When a joint capsule is injured, what happens
Increased vascularity
Thickening of capsule
Swelling → overstretching of capsule
Likely decrease in proprioception
Typically associated with ligament sprain
Can we treat a decrease in proprioception in a joint capsule? If so give an example
Yes, after ankle sprain we put people on balance routine. Because of damage to the joint capsule. We are trying to build new neurological pathways
Injury to joint capsule MAY be associated with injury to other musculotendinous structures such as
Tendinitis
Tendinosis
Muscle Strain
Two types of injury to the synovium
post-traumatic synovitis
Chronic synovitis- gradual fibrosis
What is post-traumatic synovitis
Capillaries of the synovial membrane dilate and filtration increases
Edema and exudate in the joint
Slight hyperemia (blood) of the synovial membrane
Chronic Synovitis leads to
fibrosis
What is chronic synovitis
Synovial membrane infiltrated with lymphocytes
Increased protein synthesis by the synovial cells
Lymphocytes ingest macrophages and then die
Proteolytic enzymes released
Normal tissue attacked
Reaction of synovial fluid to trauma
if trauma is minor - might see slight elevation in protein and WBC
if prolonged - WBC go up a lot and fluid becomes cloudy.
Protein and viscosity increase and if bloody this will cause damage to cartilage
How is articular cartilage’s ability to heal itself
poor
What are the two types of articular cartilage injuries
Those that do not penetrate the subchondral bone
Those that penetrate the subchondral bone
What is a partial thickness defect (in regards to articular cartilage)
- MAY heal, depending on diffusion from viable periosteum & synovium (movement, WBing, closed packed position)
- If does not heal will lead to necrosis
What is a full thickness defect (in regards to articular cartilage)
- Into subchondral bone
* Heals with fibrocartilage
Articular cartilage injury cycle
Cyclical tissue breakdown ◦ Fracturing of collagen fibers ◦ Depletion of ground substance ◦ Synovial inflammation ◦ Capsular fibrosis ◦ Altered mechanics ◦ Osteoarthritis
Symptoms of articular cartilage injury
◦ Symptoms not present until subchondral bone exposed -b/c it's aneural ◦ Dull ache ◦ Stiff- worse w/ inactivity ◦ Swelling ◦ Decreased ROM
