Knee Flashcards
ACL runs from
Intracondylar eminence anteriorly to medial aspect of lateral condyle
ACL is tight in
EXTENSION
PCL runs from
postierior intracondylar eminence posteriorly to lateral aspect of medial condyle
PCL is tight in
FLEXION
ACL resists
Ant tibial translation
Knee hyperextension
IR
ACL often torn in
Hyperextension
Valgus
Rotational
forces
MCL/LCL are tight in
EXTENSION
MCL runs
LCL runs
inferiorly and anteriorly
From medial femoral epicondyle to the tibia
LCL - from lateral femoral epicondyle to the fibular head
ACL full return post op
6 months to 1 yr
PCL often torn with
Varus
Twisting
MVA with tibia on dashboard
Fall onto flexed knee
ACL - if surgical repair with hamstring -
NO RESTRICTIVE HAMSTRING exercises for 6 wks
LCL torn with
Varus stress contact
MCL torn with
Valgus stress contact
Often rotation force
Patellar surface on femur is larger ___
Laterally!
Patella tends to glide more laterally during knee extension
Tibial condyles - which is larger
Medial!
50% larger and has 3x more cartilage than lateral
Medial meniscus is what shape and what attaches
C shaped
Attaches with MCL and Semimembranosus
Lateral meniscus is what shape and what attaches
O shaped
Attaches with PCL and popliteus
Meniscus - repair vs. removal
Repair has a longer recovery than removal
Meniscus and blood flow - Meniscal tears can heal if
They are localized to the outer/peripheral 1/3 rim/edges
This is the only area that receives blood supply
Outer 1/3 injury can heal without surgery
Inner and middle 1/3 will require menisectomy
Triad
MCL
Medial meniscus
ACL
Tear meniscus - what injury
Rotation/cutting movement
Deep flexion
Degneration
If forced into hyperextension - can be medial meniscus
With valgus (knock knee) - where is tension and where is compression
Medial - tens
Lateral - compression
Mechanical axis is displaced laterally
With varus force - where is the tension and where is compression
Medial - compression
Lateral - tens
Mechanical axis is displaced medially
With genu recurvatum where is the tension and where is the compression
Ant - compression
Post - tension
Mechanical axis is displaced ant
Bowstring effect is what
ITB and other forces tend to draw patella laterally
can lead to chondromalacia
Open chain
Tibia on femur
Concave on convex
SAME
Closed chain
Femur on tibia
Convex on concave
OPP
Screw home mechanism
With extension, ACL is tight and pulls knee into slight ER
Couples motions:
EXT of knee with ER of tibia
FLEX of knee with IR of tibia
Largest joint in the body?
KNEE?
OA in the knee is most common where
medially (from varus knee?)
TKA
Need 90 flex before dc from hospital
Knee ext is priority
Quad tendon rupture
Usually knee flexed to 90 when ruptures
Painful knee may require what with rehab
Strengthening of HIP to decrease load/forces through knee
Ottawa Rules for referring for radiograph
Hx of trauma in 55+ Tenderness at head of fibula Tenderness at patella Inability to flex knee 90 deg Inability to bear weight for 4 steps immed after injury
Patellar tendon rupture - exercise
No active extension for 6 wks (only passive)
6 to 12 month recovery
