Ligament And Joint Injuries Flashcards
What are ligaments composed of?
Collagen, elastin, proteoglycan, and other proteins
Risks associated with ligament injuries
- Ligament scars (weaker tensile strength and viscoelastic properties)
- high risk of reinjury
- decreased proproception
At what percentage of length increase will the collagen fibres begin to rupture?
4% (permanent microdamage)
Example of intra-articular ligaments
Crucial ligaments of knee (inside capsule)
Example of extra-articular ligaments
Calcaneofibular (outside joint capsule)
Example of capsular ligaments
Anterior talofibular (thickens capsule)
How do ligaments adapt to increased loading?
Slowly increase cross-sectional area
What percentage can systematic training increase ligament strength
10-20%
Passive subsystem
Non-contractile connective tissues
Active subsystem
Controlled by neural subsystem to provide dynamic joint stability
Valgus
Buckling inward (think “g” colliding)
Virus
Outward, bow legs (think “r” for rarely touch)
‘Felt my knee cap go out”
Patellar dislocation/subluxation
Hit from lateral side (valgus)
MCL, ACL
Valgus/external rotation (with or without contact)
ACL, MCL, lateral meniscus, bone bruise
Direct blow to anterior tibia
PCL
Hyperextension injury
ACL
Minor twist in older individual
Degenerative meniscal tear
Injuries that cause hemarthrosis (bleeding in the joint)
ACL tear, peripheral meniscus tear, osteochondral injuries, fractures
Injuries that should not usually cause hemarthrosis
MCL tear, central meniscus tear, PCL tear, cartilage injury
ACL bundles
1) anteromedial (resist anterior translation)
2) posterolateral bundle (resist rotation)
… no pain fibres, but proprioceptive
When is MRI imaging necessary?
All dislocated knees, surgical planning, bone damage, multiple ligaments involved
When is the ACL graft the weakest?
Right when you start to feel okay (3 to 6 months)
Modifiable risk factors in the prevention of ACL injuries
- Weak hip abductors and external rotators
- increased knee abduction during cutting and landing
Subluxation
Partial dislocation of articulating bones
Dislocation
Complete separation of articulating bones
Mechanisms for glenohumeral (shoulder) dislocation
- Direct blow to shoulder
- landing on outstretched arm
Labrum injuries (slap tear)
Surrounds socket for stability and is a connection point long head of biceps tendon
Are shoulder injuries at a high risk of recurrence?
Yes, 50 - 90 %
