Ligaments Flashcards
What are the Histological Composition of Ligaments
- 2/3 water: contributes to viscoelastic behaviour
- 1/3 solid: collagen (mainly 6 types), proteoglycans, and elasin
List possible complications to healing
failure to:
- reconnect appropriate locations on bone
- produce enough scar tissue
- produce correct type of tissue
List the ligament injury categories
Fractures
Inflammation
Systemic
Sprains
What are the functions of ligaments
- Connect two bones together
- Stabilize joints
- Shared junction of restraint
- Proprioceptor for the joint
T or F: Ligaments have both specific innervation and blood supply
True
Which region of a ligament is more avascular?
The middle region - influences healing
How does the material (solid) behaviour of a ligament respond to stress?
Crimp –> building stress –> fibers fail –> F increases –> complete disruption
What is the viscoelastic behaviour of a ligament in response to stress?
- Higher loads: Elastic property highest - able to recovery shape
- Lower loads: Viscous highest - acting as liquid that has to be squeezed to move
T or F: Hormones do not influence ligaments
False - hormones influence ligament function, and it may be gender specific (menstrual cycle, pregnancy, likelihood of benign joint hypermobility syndrome)
What are the three steps of ligament healing and length of time in each
- Inflammation - w/in 72 hours
- Proliferation- 48-72 hours after injury up to 6 weeks
- Maturation - 6 weeks or 12+ months to complete
avulsion fractures
Tensile loading of the tissue that causes the insertion stie to pull away from bone, taking a part of bone with it
enthesitis
Inflammation of insertion of ligament -> traction injury
ligament sprain
Disruptions of ligament fibers beyond elastic limits
What is apophysitis
Enthesitis in a younger child
What is Ehlers-Danlos Syndrome
A systemic ligament condition of multiple joint hypermobility
Effects of immobilization on ligamentous structure
Ligaments are strain-rate sensitive and will experience rapid deterioration without a load applied with greater than 6-9 weeks resulting in 50% reduction of strength
Effects of exercise on ligamentous structure
Increase strength and stiffness no more than 10-20%
Possible medical management of ligamentous structure
Surgery may be possible if: high risk for instability in future, associated lesions, age, type of sprain
Why is it important to evaluate a ligament strain immediately after injury?
Edema will begin to occur later and it will be hard to accurately assess and diagnose the problem
What tests can be done to determine the existence of a ligament sprain?
MRI, stress radiographs and arthrograms
When is a ligament unstable only in the position of injury
When it is only a partial tear of the ligament
What are the signs and symptoms of a grade I/mild sprain
- ROM limited in one direction only
- Pain increases w/AROM & PROM
- limited bruising
- localized tenderness over area of injury
What are the signs and symptoms of a grade II/moderate sprain
- stress test gives some laxity but not complete
- dec. ROM, painful, swelling restricts mvmt
- edema
- ecchymosis
- instability with WB
- more diffusely tender
- may be other second degree sprains in nearby ligaments
What are the signs and symptoms of a grade III/Severe sprain
- significant laxity and abnormal inc. ROM
- severe swelling
- ecchymosis or hemarthrosis
- structural, functional instability
- less painful than grade II
- May have second degree sprains in other ligaments
What are the effects of aging on ligaments (general)
- less viscous, slower cell metabolic function
- peak just following skeletal maturity
Ligaments in middle age
- insertions weaken
- less structural strength
- dec. viscosity
- dec structural length
Ligaments and older age
- clinically significant weakness
- lose water
- lose mass
- stiffness
