8: Knee Flashcards
Two types of nerve fibers to the Synovium
- Postganglionic symp adrenergic fibers
2. Unmyelinated C fibers
Postganglionic symp adrenergic fiber function
Control articular blood flow
Unmyelinated C fibers function
Pain transmission during trauma to joint
Prostaglandin E2
Inflammatory agent that can induce signaling in nociceptive fibers of the knee synovium -> pain in normal ROM
how are ACL and PCL internal ligaments
They’re within the joint capsule, but separate from joint activity and synovial fluid
ACL: two attachments
- Anterior part of intercondylar area of tibia
2. Medial side of lateral condyle of femur
Three directions ACL fibers are oriented
Superior, posterior, lateral
PCL: two attachments
- Posterior part of intercondylar area of tibia
2. Lateral side of medial condyle of femur
Three directions PCL fibers are oriented
Superior, anterior, medial
Which ligament taut when leg is flexed vs extended?
Leg flexed: PCL taut
Leg extended: ACL taut
Anterior and posterior drawer sign
Anterior: shows laxity if ACL is torn
Posterior: shows laxity if PCL is torn
Where are menisci attached to joint capsule? And by what?
External margins, by coronary ligaments
Transverse ligament
Joins two menisci at the anterior edge, allowing them to move together
Which meniscus is larger?
Medial
Which menisci’s anterior and posterior horn attaches to the ACL and PCL?
Medial meniscus
Does the medial meniscus attach to the MCL?
Yes
Posterior meniscofemoral L
Joins lateral meniscus + PCL
Popliteus tendon
Passes between lateral meniscus + LCL so these two dont touch
Which meniscus is more likely to tear?
Medial (lateral is more mobile - wont tear as easy)
Body conditions where injury can occur, causing the unhappy triad of injuries
Knee flexed + foot laterally rotated
Triad of injuries in the knee
ACL tear + MCL tear + 1 menisci tear
