knee 2 - injuries Flashcards
(98 cards)
most ACL injuries are what
(80%) non contact
what is the normal MOI of ACL
foot planted, valgus/rot load
low flexion angles
hyperext load (step in pot hole)
what are some examples of activties that lead to ACL injury
- Cutting combined with deceleration
- Landing from a jump in or near full extension
- Pivoting with knee near full extension
- Deceleration with knee internal rotation
- “Dynamic Valgus”: Femoral adduction, Knee abduction, Ankle eversion
what does a contact ACL injury look like
Posteriorly directed blow to anterior femur
blow to the lateral knee when the foot is planted
(dashboard, hyperext)
what is the general presentation of a ACL injury
popping,
giving away, buckling
- episodes of giving way with ADLs
severe pain
Continued effusion
flexed knee gait
Limited range of motion
what is quad inhibition
process in which quadriceps activation failure is caused by neural inhibition, is common following knee injury or surgery
what are the DD for ACL injuries
- Multiple ligament injuries –MCL, PCL
- Meniscal involvement
- Unhappy Triad (O’Donoghue)
- MCL, medial men, ACL
- Patella subluxation/dislocation
what is the PCL MOI
hyperflexion
Fall on a flexed knee with foot in plantarflexion
Hyperextension mechanisms
* Step in a pothole
Blow to anterior tibia (Dashboard)
what is the general presentation of a PCL MOI
posterior knee pain
less effusion compared to ACL
flexion beyond 90 may be painful
hard time descending stairs, squatting, running
less quad inhibition then ACL
what is the DD for PCL injury
- Patellofemoral pain: Patients with chronic PCL insufficiency can develop PFPS
- Need to rule out posterior lateral complex involvement
- False + Anterior Drawer Test
- Consider chondral lesions when MVA trauma is involved
- Meniscal tears at the posterior horns with hyperflexion injuries
what are chondral lesions
caused through degradation of joint cartilage, in response to metabolic, genetic, vascular and traumatic stimul
are PCL injries normally large traumatic events
no
Posterolateral Corner Injuries MOI
- Posterolateral-directed force to the anteromedial tibia
- Knee hyperextension
- Severe tibial external rotation with the knee is low angles of flexion
- Varus forces to a flexed knee
- Atraumatic may present as chronic laxity without a PCL component
what are the structures we find in the posterio-lateral corner
static: PCL, LCL, posterior horn of the lateral meniscus, PL capsule
dynamic: ITB, popliteus, biceps femoris
MCL MOI
- Controlling excessive valgus forces
- With the LCL responsible for preventing excessive Femoral IR and Tibial ER
is the MCL attached to anything else
yes - medial meniscus, and ACL
what does the MCL feel like
flat and broad
what is the main purpose of the MCL
controling knee valgus
what is the secondary purpose of the MCL
with the LCL preventing excessive femoral IR and tibial ER
what is the DD for MCL
- Medial meniscal tear
- ACL / PCL
- Epiphyseal plate injury
- Patella dislocation
is the LCL attached to anything
no - not like the mCL
what structure seperates the lateral menicus and the LCL
popliteus
what forces does the LCL prevent
resists varsus stresses
we do not get hit from the inside of the leg so this does not get injuried as often
what else does thee LCL prevent - movement-wise
lateral tibia rot
median femoral rotation