Knee Flashcards
1
Q
3 landmarks of distal femur
A
- Lateral condyle
- Medial condyle
- Intercondylar notch/groove
2
Q
Which tibial condyle is larger?
A
Medial
3
Q
Fibula has ____________ function @ knee
A
No direct
4
Q
3 parts of tibial articulation surface
A
- Lateral plateau
- Medial plateau
- Intercondylar region
5
Q
Anterior surface of patella is ________ in all directions
A
Convex
6
Q
Posterior surface of patella is covered with ___________
A
Cartilage
7
Q
Where does the patellar tendon attach on the patella?
A
Apex
8
Q
3 facets of post patella
A
Medial, lateral, odd
9
Q
Primary function of patella
A
Increase angle of application - (MA of quads)
10
Q
Secondary function of patella
A
Protect quad tendon from excessive friction
11
Q
If no patella, quads are __________
A
On slack; active insufficienc
12
Q
Term for “knock kneed”
A
Genu valgum
13
Q
Angle ________ is excessive for genu valgum
A
Of femur in relation to tibia (<170 degrees)
14
Q
Angle ________ is excessive for genu varum
A
Of femur in relation to tib (>180 degrees)
15
Q
“Bow leg”
A
Genu varum
16
Q
Normal alignment of femur
A
Shaft of femur slightly medial
17
Q
The joint capsule is ______, ____________ and ________ with several recesses
A
Large, complexly attached, lax
18
Q
How is joint capsule reinforced posteriorly?
A
Muscles and popliteal ligs
19
Q
How is capsule reinforced M/L?
A
Collateral ligs
20
Q
How is capsule reinforced anteriorly?
A
Vastus medialis, lateralus, MPFL, retinacula
21
Q
Unique thing about synovial lining of knee
A
Most extensive and involved in the body
22
Q
Where is the bursa located
A
Suprapatellar
23
Q
Purpose of fat pads
A
Reduce friction
24
Q
Shape of menisci
A
Crescent
25
Composition of menisci
Fibrocartilaginous discs
26
Shape of medial meniscus
Semicircular
27
Shape of lateral meniscus
Circular
28
Where are menisci thick and thin?
Thick peripherally, thin centrally
29
Blood supply of menisci is greatest in the ____________
Periphery
30
What anchors the menisci?
A/P horns
31
3 secondary attachments of menisci
1. Quads (bilaterally)
2. Semimembranosus (bilaterally)
3. Popliteus to lateral only
32
2 primary functions of menisci
1. Reduce compressive stress
| 2. Stabilize joint during motion (restrict translation)
33
3 secondary functions of menisci
1. Lubricate art cartilage
2. Proprioception
3. Guide arthrokinematics
34
Why is rotation not possible in extension?
Bony congruency
35
Flexion/extension AOR
M/L, migrating
36
Axis of flex/ext is ________
Oblique
37
In full flexion, the tibia is slightly ________ to the femur
Medial
38
Axial rotation _________ with knee flexion
Increases
39
At 90 deg knee flexion: _______ total axial rot
40-45 degrees
40
When tibial tuberosity is lateral to anterior distal femur
External rotation
41
What does tibia need to do to "unlock" to go into flexion?
IR via popliteus
42
Describe the arthrokinematics at the knee during ext
T-on-F: tib rolls and glides anteriorly
F-on-T: fem roll anteriorly and glide posteriorly
43
Describe action of popliteus during flexion both ways
T-on-F: popliteus initiates tib IR
F-on-T: popliteus initiates fem ER
44
____________________ dictates arthrokinematics during final 30 degrees of KE
Joint arthrology
45
Lock:
Unlock:
ER
| IR
46
Is an extension loss or a flexion loss more meaningful for a pt?
Extension
47
Collateral ligs provide ________ plane stability against _____________ forces
Frontal; varus/valgus
48
Cruciate ligs provice _____________ stability
Multiplanar
49
MCL resists _______ stress
Valgus
50
Secondary role of MCL
Preventing anterior translation
51
______ may place increased stress on ACL if injured
MCL
52
MCL has the capacity to __________
Heal; vascularized
53
MCL works ________ in flexion
Harder
54
Resists varus stresses
LCL
55
LCL accounts for more restraining force in more ___________
Flexion
56
Named for their attachment to the tibia
cruciate ligs
57
These ligs work mostly in the saggital plane
Cruciate
58
Cruciate ligs guide _________
Arthrokinematics
59
Cruciate ligs contribute to ________________
Proprioception
60
Where ACL originates and inserts
O: anterior tib plateau
I: lateral femoral condyle
61
When is ACL most taut?
With knee close to extension
62
ACL is most commonly injured when...
Knee is slightly flexed and tib is rotated in either direction
63
How to strain ACL
Forceful contraction of quads, especially near full extension (pulls tib anteriorly)
64
Origin and insertion of PCL
O: posterior intercondylar area of tib
I: medial femoral condyle
65
Primary function of PCL
Restraint to post displacement of tibia on femoral condyles (or ant displacement of femur in closed chain)
66
When are fibers of PCL taut?
Greater flexion
67
Contraction of the ________ can slide tib/fib posteriorly
Hamstring
68
Most injuries of PCL
Traumatic
69
Interface between the patella and intercondylar groove of femur
Patellofemoral joint
70
Max contact of PFJ ______ of total surface area
30%
71
Describe where patella is during extension and flexion
Extension: inferior pole of patella with most contact
Flexion: superior pole of patella with most contact
72
Talk about the motions of the patella relative to the ___________________
Inferior pole
73
3 movements of the patella
1. Shift
2. Tilt
3. Rotation
74
What comprises the q angle?
ASIS --> mid patella
| Tib tub --> mid patella (vertical)
75
Approx q angles in women and men
15 degrees in women
| 11 degrees in men
76
Abnormal q angle
>15 degrees
77
Knees over toes in squat increases
Resultant forces of quads
78
Quad efficiency is affected by _____
Patella
79
Quads produce a force __________ than hamstrings
2/3 greater
80
When do quads produce max torque?
40-70 deg flexion
81
2 functions of quads
1. Dampens impact of loading
| 2. Accelerates tib or femur for tasks requiring knee extension
82
In open chain, when is external moment arm greatest in quads?
Seated knee extension
83
In a squat, when is external moment arm the greatest?
Deep squat (90 degrees of flexion)
84
When are hamstrings most active?
Walking/running
85
Role of hamstrings on tibia and femur
Tib: accelerate or decelerate during T-on-F movements
Femur: stabilizer
86
When can hamstrings produce max torque?
Near full knee extension (seated)
87
Provides medial stability and functions to IR tibia
Pes anserine
88
Muscles responsible for IR tibia
Sartorius and gracilis
89
2 actions of popliteus
IR and knee flexion
90
3 major LATERAL forces on patella
1. IT band
2. Bowstringing force on patella (caused by quads/pat tendon)
3. Lateral patellar retinacular fibers
91
Major MEDIAL forces on patella
1. VMO
2. Raised lateral facet of IC groove
3. Medial patellar retinacular fibers
92
What motions increase bowstringing force on patella?
Excessive knee external rotation and valgus
93
How does a deep squat affect the bowstringing of the patella?
Increased forces of quads/patellar tendon increase bowstringing resultant force
