Knee Ligament injury and rehab Flashcards
1
Q
What does the MCL restrain
A
- 1ºrestrain: valgus
- 2ºrestrain: hyperextension and tibial rotation
- more slack in flexion and taut in extension
2
Q
What does the LCL restrain
A
- primary restrain = varus
- secondary restraint = hyperextension and rotation
- slack on flexion and taut in extension
3
Q
ACL attachments
A
- anterior intercondylar area of tibial plateau
- runs in a posterior lateral direction
- medial side of the lateral femoral condyle
4
Q
What does the ACL limit
A
- anterior translation of the tibia on the femur (OC)
- posterior translation of the femur on the tibia
- secondary restrains varus and valgus forces as well as ER
5
Q
How do the ACL fibers react during flexion and extension
A
- anterior medial fibers are taut in flexion
- posterior-lateral fibers taut in extension
- anterior shear/tension in open chain extension
6
Q
PCL attachements
A
- posterior tibia plateau to the lateral side of the medial femoral condyle
7
Q
What does the PCL limit
A
- limits posterior translation of the tibia on the femur
- anterior translation of the femur on the tibia
- secondary restrains = rotation, varus, and valgus
8
Q
Joint capsule of the Tibiofemoral joint
A
- secondary restrain in all directions
- a completely torn ACL –> joint capsule will take up slack as well as MCL/LCL/PCL
- therefore do not want to do activities that will stretch
- intracapsular/extra synovial
9
Q
Mechanism of injury common in the knee
A
- Valgus/ER/Flexion - Likely to injure MCL, ACL, Medial Meniscus (possibly lateral meniscus)
- Hyperextension: likely to injure the ACL in a non contact mechanism (common with female jumping athletes)
- Forced tibial ER: torn ACL
- Forced tibial IR: ACL wraps around PCL (can tear)
10
Q
ACL tears common signs and symptoms
A
- Acute blow or twisting injury
- immediate effusion (bleeding into the joint)
- inability to continue to play
- 75% chance ACL injury diagnosis on history alone
11
Q
Describe an torn ligament in relation to the stress strain curve
A
- stretch into plastic
- 4% strain = microtrauma
- 6-8% = 1º-2º strain
- > 8% = 3ºstrain/tear
12
Q
How can you diagnosis grade of sprain with the amount of translation
A
- Grade 1 = 0-5 mm of translation with lachmans
- grade 2 = 5mm-1cm of translation
- grade 3 = >1cm
13
Q
What is another way to diagnosis the sprain of an ACL
A
- end feel can be used
- normal abrupt/firm
- abnormal = soft as ACL is not stopping
14
Q
Requirements for ligament healing
A
- torn ligament remain in proximity or within highly vascularized tissue
- Controlled motion stress stimulates and directs better healing
- protect against harmful stresses
15
Q
How well do the MCL and ACL heal
A
- MCL any grade will heal as it is highly vascularized
- ACL grade 1&2 can scar and heal
- ACL grade 3 is not going to heal as it does not have enough blood flow
