Ligament Injuries To The Knee Flashcards
What kind of collagen is present in ligaments?
Type 1
What are ligaments structured to resist?
Tension
How are most ligaments packaged?
Into bundles
What will load do in elastic properties?
Deform to proportion of load when it is applied
Return to original shape when it is removed
What are viscous properties?
Resistance to flow of fluid
What type of fiber is scar tissue?
Type 3
What does moderate stress induce?
Organization of collagen in more parallel arrangements
When does peak energy absorption performance of a ligament occur?
Time of skeletal maturity (gradually declines after)
What is the relationship between the MCL and meniscus?
Grade 2 or 3 MCL injury usually involves meniscus too
What are the major functions of ligaments?
Stability and proprioception
What are the 4 major ligaments of the knee?
ACL
PCL
MCL
LCL
What ligaments have attachment to the meniscus?
ACL
PCL
MCL
What is the function of the posterior capsule?
Resists knee extension
What would a second degree ligament sprain fall under in the stress strain curve?
Plastic region
What would a first degree ligament sprain fall under in the stress strain curve?
Elastic region
What would a third degree ligament sprain fall under in the stress strain curve?
Failure region
How long does a grade 2 ligament injury take to heal?
4-6 weeks
What is a grade 1 ligament strain?
Pain with stress testing (no instability)
What is a grade 2 ligament strain?
Pain with stress testing (instability, firm end feel)
What is a grade 3 ligament strain?
Complete tear (instability, no firm end feel) (less pain)
What are younger children more likely to get over a ligament injury?
Avulsion fracture
What are the special tests for the MCL?
Valgus stress test at 20-30°
Does the valgus stress test help rule in or rule out?
Rule out (high sensitivity)
What are special tests used for the LCL?
Palpation
Varus stress test at 20°
What are the special tests used for the ACL?
Lachman’s
Anterior drawer
Is Lachman’s good at ruling in or out?
Both (high sensitivity and specificity)
Is the anterior drawer good and ruling in or out?
Ruling in (high specificity)
What are special tests used for the PCL?
Sag sign
Posterior drawer
Are sag sign and posterior drawer good at ruling in or out?
Both (high sensitivity and specificity)
When should a decision to be made to have ACL surgery post injury?
6-12 months
What do copers and non copers have in common?
Poor quad control
What percentage of grade 3 PCL sprains are repaired surgically?
10%
How long does a PCL take to heal with surgery?
18 months
What is a quad allograft compared to a patellar autograft?
Larger and stronger
What is there less of with a quad autograft?
Anterior knee pain and pain with kneeling
What is a complication of getting a quad autograft?
More difficult to harvest and surgeons have less experience
How should you be early on if you get a hamstring allograft?
Less aggressive
What should you not do if you get a hamstring allograft?
No isolated hamstring strengthening until week 8
What is at an increased risk of you get a quad autograft?
Patellar fracture
What is the first goal when treating a patient who had an ACLR?
Knee extension as quickly as possible
What is the most important intervention to prevent a second ACL injury?
Neuromuscular control
What is the weakest time for a graft?
6-8 weeks
Return to participation
Practice (non contact)
Return to sport
Riding bench, time constraint (playing different position)
Return to performance
Back in sport at a higher level than before
When should you perform a return to sport assessment?
Week 8 and then gradually throughout rehab
What is an important limb symmetry test that should be included in your return to sport assessment?
Hop test
