lecture 5: Tissue characteristics and healing Flashcards
Injury classification
- used to be called acute or chronic
- confusing because all injuries are technically acute - something initiates them
- at some point if the injuries do not heal, they are termed chronic
traumatic (acute) injuries
- occur suddenly and have a clearly defined cause or onset
- occur when tissue loading is sufficient to cause sudden irreversible deformation of the tissue.
- usually in high speed sports with or without high energy contact.
what factors cause injuries?
- extrinsic/ external factors
- intrinsic/internal facts
extrinsic/external factors
- originating outside the anatomical limits of a tissue/person.
intrinsic/internal factors
- belonging to or lying within a given part person/tissue
– and – issue combine together to cause further injuries
extrinsic and intrinsic
muscle characteristics
- contractile tissue with central function to generate power
- well vascularized so it is good with oxygen and nutrients which is good for healing quickly
- it also bleeds lots
what are muscle tears called?
- strains
when looking at strains, what do you need to consider?
- percentage of fibers that have been torn
- the ability to move through range, stretch etc
- strength generated (out of 5) on the oxford scale
- pain (someones stronger pain is good)
grading muscle strength (oxford scale): grade 5
- normal
- full strength. throughout available range compared to other side
grading muscle strength (oxford scale): grade 4
- good
- near full strength through available range when compared to other side
grading muscle strength (oxford scale): grade 3
- fair
- full range of motion against gravity only
- when you add resistance, the person can not completely overcome gravity, however, they can move with no resistance
grading muscle strength (oxford scale): grade 2
- poor
- can complete full available range with gravity eliminated
- changing the plane of movement so that you have eliminated gravity
grading muscle strength (oxford scale): grade 1
- trace
- able to palpate (feel) a muscle contraction when the patient tries to contract
grading muscle strength (oxford scale): grade 0
- nothing happens when the patient tries to contract
types of contractions
1: isometric
2: concentric
3: eccentric
isometric
- muscle contraction in which length of muscle stays constant
- i.e. no movement
concentric
- muscle shortens while contracting against resistance
- i.e. bicep curl going up
eccentric
- muscle lengthens while contracting against resistance
- greater risk of injury
- i.e. bicep curl going down
muscle injuries
- generally occur in 2 ways
1: distension (strains/”pulled muscle”)
2: direct trauma - contusion (or bruise)/ laceration
muscle strains
- strains usually occur at the musculotendinous junction
- more common in 2 joint muscles
- strains occur as a result of forcible stretching of a muscle, either passively or when the muscle is activated.
– + – = STRAIN
Active contraction + passive stretch
what are examples of 2 joint muscles
- biceps
- abductor femoris
- hamstrings
grade 1 strain
- usually less than 20% of fibers torn or stretched
- near full ROM with some discomfort near the end
- good strength 4-5/5
- slight pain/discomfort
- no palpable divot
grade 2 strain
- usually 20-80% of fibers are torn
- significantly less ROM with some discomfort near the end.
- poor strength - 50% or 2-3/5
- significant pain/discomfort
- can have palpable divot
grade 3 strain
- 80% to complete rupture
- PROM only - may not have pain on stretch because the muscle is not attached, therefore there is no tension.
- poor strength - 0-1/5 on oxford scale
- variable pain (may be initial then no pain or discomfort)
- large gap or muscle retraction
muscle contusions
- can be any muscle, but quads are most common
- due to vascularity, ecchymosis are quite common
- all result in internal bleeding
ecchymosis
- the bruising or blood showing up under the skin
intra = blood stays in the fascia
inter = blood leaks out
intramuscular
- no injury to fascia
- blood is trapped in muscle
- signficantly longer healing time
- increased compartment pressure
- decreased flow of oxygen and nutrients
- chemical irritation
- take longer to heal than intermuscular
inter-muscular injury
- fascia is injured
- blood flows out between the muscles
-will see ecchymosis faster - heals faster
- no increased pressure
- more blood flow
- increased healing
- blood can be absorbed
- no irritation
tendon characteristics
- connective tissue that attaches muscle to bone
- function is to transfer force from muscles to the skeleton
-65-80% type 1 collagen - arranged into parallel bundles of various sizes
- want these bundles to be a lot of collagen and not a lot of elastin
tendon injuries
can be
1: over use
2” traumatic
overuse tendon injuries
1: tendinitis
2: tenosynovitis
3: paratenonitis
4: tendinosis
5: bursitis
6: periostitis
traumatic tendon injuries
1: laceration (skate)
2: penetrating injury (stab)
3: rupture (achilles, quads)
4: acute tendon strain/tear
these usually are more inflammatory
tendinitis/paratenonitis
tendinitis - is inflammation of the tendon itself and is relatively rate
paratenonitis - inflammation, pain, and crepitation of the paratenon as it slides over the structure
acute irritation is usually triggered by:
- extrinsic factors such as rub from equipment or “too much, too soon”
- internal factor such as rub over bone
tendinitis leading to tendinosis
- if repetitive overuse continues and an inflamed or irritated tendon fails to heal, the tendon begins to degenerate
- primary concern changes over tendon inflammation to tendon degeneration, a condition that is called tendinosis
tendinitis = when you have inflammation of the joint
tendinosis = when you actually see changes in the structure of the joint (is not inflammatory, degenerate process where the tissue begins to change)
tendinosis
- chronic pathological changes brought about by repetitive micro-trauma
- inflammatory cells are absent
- characteristic changes in collagen fiber structure
- abnormal vascularity
collagen structural changes in Tendinosis
in normal tendons the collagen fibers line up and there are many nuclei, however, in tendinosis, the collagen fibres disarray, there is loss of parallel bundles, and fewer cell nuclei
vascular changes in tendinosis
normal tendon will be well developed with evenely spaced vasculature.
tendinosis has hyper vascularity, increased number of poor-quality blood vessels (neovascularization)
do you have good or bad blood flow in tendinosis?
you have bad because it is hyper vascular, and the increased number of poor-quality blood vessels also known as neovascularization
ligament characteristics
- connect bone to another bone
- made predominantly out of collagen
- higher content of elastin than tendons - passive stabilizers
- made predominantly out of collagen
- usually traumatic mechanism of injury
- well innervated so it gets good information about the position, movement and pain. it is also very important for proprioception and rehabilitations
3 types of ligaments
1: intra-articular
2: capsular
3: extra - capsular
intra- articular ligaments
- inside a joint or joint capsule
- total rupture will NOT heal
- blood supply from ends - minimal to middle portion
- ACL
capsular ligaments
- where ligament projects as a thickening of a joint capsule
- total rupture - excellent healing
- good blood supply
- ATFL , MCL
extra - capsular ligament
- outside of the joint capsule
- similar to intra-articular
-CFL, LCL - if you tear them it will swell up greatly
properties of ligaments
- wave or cromp across ligament
- built into the structure of the ligament
- injury can be closely correlated to the load - deformation curve
- 3 phases of curve
- toe region
- linear region
- rupture region
the toe region and early liner region of ligaments
- initial concave region
- represents normal physiological range of strain = 0-2% of length
- early liner region 2-4% due to flattening of crimp
- repeated cycling of stretch in this range is reversible
(basically how we live our everyday lives)
late linear region of ligaments
- pathological irreversible ligament elongation occurs
- as this continues intra and inter molecular cross- links are disrupted until macroscopic failure is clinically evident
- early part = mild/grade 1 sprain < 50%
- 2nd part = grade 2 sprain and obvious clinical laxity
rupture region of ligaments
- failure point at approx. 10% complete rupture
- grade 3 sprain
- decreased pain vs. grade 2
muscle strains wer grade —-
ligament sprains we grade —
1-3
1-3
ligament tears are called –
- sprains
- need to consider:’
- % of fibers torn
- ability to move through range.. stretch
- laxity on testing and end point
- pain - sometimes more is better?
what is end point?
- if you stretch something and feel make a hard stop then you know the ligament is still attached. but if it is not you won’t feel the hard end feel
grade 2 Sprain
- full ROM
- slight pain on palpation
- no joint laxity (good stability)
- people are still very functional
- has an endpoint
when testing for sprains what are you looking for?
1: pain
2: laxity
3: end point
grade 1 sprain
- significant loss of motion
- significant pain on palpation
- significant joint laxity
- has an endpoint because it is still holding on my 20+%
grade 3 sprain
- loss of motion
- pain on palpation
- gross laxity +++ (it will pretty much slide forever)
- has no endpoint!
- might have pain on palpation at first, but when you see them the next day they might not have pain because it is not attached.
fracture characteristics
- can be divided into open (compound) or closed (simple)
- open = bone breaks through surrounding tissue and skin
- closed = little or no displacement of bone through surrounding tissue
fracture classifications
1: greenstick (usually in younger children)
2: spiral (occurs due to a twisting motion)
3: comminuted (where the bone fractures into more than 3 pieces)
4: transverse (when the fracture going right across horizontally)
5: compound (when both of the bones break)
6: vertebral compression (usually happens to older people in the T-spine)
contusion VS. fractures
- when trying to figure out fractures you want to do
1: direct test (palpation)
2: indirect test (passive pronation is an example for forearm fracture) (ask them to pronate and see if there is pain in the top of the arm) - indirect tests = not actually touching it but causing pain by asking the patient to do a movement.
where can contusion occur?
1: bone
2: cartilage
3: muscles
phases of healing
- body goes through a predictable sequence of healing
- our treatment choice will be dependent on the phase of healing
- we have minimal ability to speed up this process, but interfering with this sequence will slow both recovery and return to sport!
inflammatory phase
- generally 1st, 3-4 days
- cellular injury = altered metabolism + release of chemical mediators/proteins
- these cause the inflammatory response
primary and secondary damage
primary
- damage at time of injury (immediately irreversible)
- can not do anything about it in the moment
secondary
- damage by released proteins
- damage as a result of body process
- edema
- damage due to decreased blood flow
- decreased oxygen
signs and symptoms of inflammation
- redness
- swelling
- pain
- local heat
- loss of function
inflammatory stage
1: red
2: hot
3: swollen
4: pain
a sub cycle occurs as the result of pain, muscle spasm and ischemaia increases the possibility of atrophy over a period of time.
pain, the muscle tightens, spasm, decreases blood flow to the area, ischemia, muscle no longer getting blood, cause pain because you are starving it from nutrients and then it goes around again
repair (fibroblastic) phase
- 72 hours to 6 weeks
- proliferative and regenerative healing leading to formation of connective tissue scar and repair of injured tissue
- fibroplasia begins within the first few days and the inflammatory sings should be
- ## (think of it as a can of worms)
repair (fibroblastic) pahse part 2
growth of endothelial capillary buds into the wound is stimulated by lack of oxygen
- these new growths allow increase oxygen and blood flow
- body lays down type 3 collagen
- weak tensile strength
- BEWARE - initially very delicate scar but increase in collagen fibers strengthens it
- the goal of this is to protect athletes from themselves because they are not yet ready to go back to sports
remodelling/maturation phase
- usually firm, strong non-vasular scar by end of 3 - weeks
- long-term process (6 weeks to years)
- with increased stress and strain the collagen changes to type 1 and beings realignment
- by the end of this stage we might be able to have full ROM
- wolfs law-bone and soft tissue will respond to the physical demands places on them, causing them to align along lines of tensile force
- critical that injured structures be exposed to progressively increasing loads
- can work up to aggressive AROM and strengthening to facilitate remodelling and realignment
- watch out for pain and swlling after exercise
day of injury healing process in tendons and ligaments
phase: immediately post - injury
process: clot formation around the wound
0-1 days injury healing process in tendons and ligaments
phase: inflammatory
process: first battery of growth factors and inflammatory molecules produced by cells within the blood clot
1-2 day of injury healing process in tendons and ligaments
phase: inflammatory
process: invasion by extrinsic cells, phagocytosis
2-4 day of injury healing process in tendons and ligaments
phase: proliferation
process: further invasion by extrinsic cells, followed by a second battery of growth factors that stimulate fibroblast proliferation
4-7 day of injury healing process in tendons and ligaments
phase: reparative
process: collagen deposition; granulation tissue formation; revascularisation
7 - 14 day of injury healing process in tendons and ligaments
phase: reparative
process: injury site becomes more organized; extracellular matrix is produced in large amounts
14-21 day of injury healing process in tendons and ligaments
phase: remodelling
process: decreases in cellular and vascular content; increases in collagen type 1
21 + day of injury healing process in tendons and ligaments
phase: remodelling
process: collagen continues to become more organized and cross-linked with heathly matrix outside the injury area. collagen ratios, water content and cellularity begin to approach normal levels
