KINES: Knee Complex Flashcards
1
Q
what forms the knee complex
A
tibiofemoral and patellofemoral joint
2
Q
what type of joint is the tibiofemoral joint
A
double condyloid or modified hinge joint
3
Q
what are the 2 planes of movement of the knee joint
A
primary - sagittal for flex/ext
secondary - transverse for tibial ER and IR
4
Q
what type of joint is the patellofemoral joint
A
non-synovial or false
5
Q
between the 2 femoral condyles which is larger
A
larger medial condyle
6
Q
compare the position of medial and lateral condyle
A
medial - shifted posteriorly and more distal
lateral - shifted anteriorly and more inline w shaft of femur
7
Q
what results due to the larger medial condyle
A
greater radius of curvature and some rotatory movement due to the imbalance of the shape
8
Q
which of the tibial plateaus are larger
A
media to match the condyles
9
Q
discuss the tibiofemoral alignment
A
shaft of femur is not in line w tibia - obliquely oriented
10
Q
normal physiologic valgus angle
A
175-185 degrees
11
Q
anatomical/longtudinal axis of femur
A
oblique
12
Q
anatomical/longtudinal axis of tibia
A
vertically oriented
13
Q
what happens if physiologic angle is greater than 185
A
genu valgum/knock knees
14
Q
what happens if physiologic angle is less than 185
A
genu varum/bow legs
15
Q
what structure is stretched in genu valgum
A
medial collateral ligament
16
Q
what structure is stretched in genu varum
A
lateral collateral ligament
17
Q
what is mechanical axis
A
weight bearing line - passes at center of hip joint, knee joint and ankle joint
18
Q
what happens to mechanical axis during single leg stance
A
axis shifts medially - compressive force on medial and distractive on lateral
19
Q
normal value of Q angle
A
10-15 degrees
males - 14 degrees
female - 17 degrees
20
Q
why do females have higher q angles
A
bcs of wider pelvis and short stature
21
Q
what does the q angle represent
A
the vector for combines pull of the quads and patella tendon; influences amount of force generated
22
Q
where is q angle measured
A
ASIS-midpoint of patella
tibial tubercle to midpoint of patella
23
Q
what are menisci
A
fibrocartilaginous discs - gel like structure
24
Q
purpose of menisci
A
increases concavity of tibial plateau and increases congruence
25
3 functions of menisci
shock absorber and pressure distribution
friction reduction
absence results to injuries
26
compare the medial and lateral menisci
lateral - smaller and circle
medial - larger and C-shaped
27
describe the structure of menisci
thick on outer/periphery and thinner on central area
28
compare the periphery and central area of menisci
cappilaries only present on periphery
inner aspect is avascular
29
explain the healing process in menisci
injuries on outer periphery will have better prognosis than inner aspect
30
what connects the 2 anterior horns of menisci
transverse ligament
31
what are the attachments of the menisci
transverse ligament
collateral ligaments
joint capsule
tendons
coronary ligaments
32
function of coronary ligaments
stabilizes meniscus betw femur and tibia
keeps menisci kept in place in all motions - absence = unstable
33
attachments of medial meniscus
MCL
ACL - anterior horn
PCL - posterior horn
semimembranosus
34
attachments of lateral meniscus
LCL
ACL - common tibial attachment
popliteus
35
what influences meniscal motion
structures around it dictate amount of stabilization
36
compare medial and lateral meniscus in terms of stabilization
medial has more attachments kaya greater risk for injury kase not as freely movable
37
CPP of knee
full knee extension with tibial ER
38
OPP of knee
25-30 deg flexion
39
what are the layers of joint capsule
fibrous capsule and synovial membrane
40
which is the superficial layer of the joint capsule
fibrous capsule
41
which is the deep layer of the joint capsule
synovial membrane
42
attachments of the fibrous capsule
distal femur, proximal tibia, patella, quadriceps and patellar tendon
43
function of fibrous capsule
creates a tight seal and encloses synovial fluid
44
what forms the extensor retinaculum
fibrous capsule
lateral patellar retinaculae
medial patellar retinaculae
45
function of synovial membrane
secrete and absorb synovial fluid
46
what is the position of synovial fluid in knee extension
pushed anteriorly
47
what is the position of synovial fluid in knee flexion
pushed posteriorly
48
what is the position of synovial fluid in knee OPP
even distribution of fluid
49
what happens to synovial fluid in injury
inflammation or swelling - compression of structures nd pain
patient assumes semiflexed bcs comfort
50
function of fat pads
shock absorbers
reduce frictional surgace
51
what are the fat pads
anterior suprapatellar
posterior suprapatellar
infrapatellar
52
other name for infrapatellar fat pad
hoffa's fat pad
53
describe innervation in fat pad
very rich kaya very sensitive cla
too muhc compression = pain = fat pad impingement syndrome
54
describe the synovial membrane in embryonic stage
separated into lateral and medial compartments
divided by synovial septum
55
describe the synovial membrane in 12 wks
synovial membrane is partially resorbed; mga na rretain = plicae
56
what are plicae
pain sensitive and can be irritated and inflammed = patellar plicae syndrome
57
locations of plicae
inferior - superior - medial - lateral
58
bursa between patella and skin
prepatellar
59
bursa between quads tendon and femur
suprapatellar
60
bursa between tendon and skin in front of patellar tendon
superficial infrapatellar
61
bursa between tendon and skin behind of patellar tendon
deep infrapatellar
62
bursa on pes anserinus muscles
pen ansirinus or subsartorial
63
bursa between semimebranosus and bone
semimebranosus
64
small bursa found posteriorly
popliteal
65
ligament that controls varus forces
LCL
66
what does LCL merge with
biceps femoris tendon; conjoined tendon
67
LCL is a secondary restraint for
tibial ER
68
ligament that controls valgus forces
MCL
69
MCL is a secondary restraint for
excessive anterior tibial translation
70
attachment of ACL
medial tibial plateau to medial surface of lateral femoral condyle
71
direction of ACL
SPL
72
location of ACL
intracapsular and extrasynovial
73
unidirectional control of ACL fixed femur
prevent excessive anterior translation of tibia
74
unidirectional control of ACL fixed tibia
prevents posterior rotation of femur on fixed tibia
HYPEREXTENSION
75
multidirectional control of ACL
supports knee joint laterally and provides stabilazation anterolaterally and anteromedially
76
what are the 2 bundles of ACL
AMB and PKB
77
where is AMB taut
flexion beyond 90 and hyperext
78
where is PLB taut
hyperextension
79
what happens in traumatic hyperex of ACL
injures both bundles
80
where is ACL laxed
at midrange
81
attachment of PCL
lateral tibial plateau to lateral surface of medial femoral condyle
82
direction of PCL
SAM
83
location of PCL
intracapsular and extransynovial
84
unidirectional control of PCL on fixed femur
prevents excessive posterior translatin of tibia
85
unidirectional control of PCL on fixed tibia
prevents excessive anterior translatin of femur
86
multidirectional of PCL
stabilies posterolaterally and posteromedially
87
ACL or PCL
larger cross-sectional area
PCL
88
ACL or PCL
less oblique
PCL
89
ACL or PCL
stronger
PCL
90
ACL or PCL
shorter
PCL
91
ACL or PCL
more commonly injured
ACL
92
what does PCL resist secondarily
varus forces and too much tibial IR
93
expansion of semimembranosus muscle
oblique popliteal ligament
94
attachment of oblique popliteal ligament
posterior joint capsule to posterior medial tibial condyle
95
function of oblique popliteal ligament
posteromedial control/support
96
attachement of posterior oblique ligament
adductor tubercle and MCL joing to the posteromedial tibia and medial meniscus
97
fucntion of Posterior oblique ligament
Reinforces the posteromedial aspect
98
function of arcuate ligament
reinforces posterolateral aspect
99
what is the meniscofemoral ligament
not a true ligament bcs does not attach to 2 bones
100
attachement of meniscofemoral ligament
lateral meniscus to PCL and medial femoral condyle
101
name for anterior fibers of meniscofemoral lgiament
ligament of Humphry
102
name for posterior fibers of meniscofemoral lgiament
ligament of wrisberg
103
discuss the arthrokinematics in OKC knee ext
concave tibia moves
tibial will roll and glide anteriorly
104
discuss the arthrokinematics in OKC knee flex
tibial rolls and glides posteriorly
105
discuss the arthrokinematics in CKC knee flex
convex femur moves
femur roll posteriorly but glides anteriorly
106
discuss the arthrokinematics in CKC knee ext
femur rolls anteriorly and glide posteriorly
107
how many degrees of freedom does the knee have
2
108
what is the screw home mechanism
locking mechanism of knee at terminal extension to avoid buckling during WB
109
factors of screw home mechanism
bone and joint
ligament
muscle
110
explain the bone nd joint factor of SHM
larger medial femoral condyles and medial tibial plateau
111
explain the ligament factor of SHM
ACL in ext pulls tibia = ER
112
explain the muscle factor of SHM
q angle or lateral pull of quads = ER of tibia in ext
113
muscle responsible for unlocking SHM
popliteus
114
muscle responsible for locking SHM
inhibiting popliteus
115
what divides the medial and lateral facets of the patella
vertical ridge
116
what separates the medial and odd facet
secondray vertical ridge
117
5 facets of the patella
superior
inferior
lateral
medial
odd
118
fucntion of pattela
anatomic pulley of quads - increases moment arm - increase toruque
reduces friction bet quads and patellar tendon and femoral and tibial condyles
119
patellar contact when knee is ext
only inferior pole
120
patellar contact when knee is 20 deg flexion
inferior facet in contact
121
patellar contact when knee is 45 deg flexion
middle portion in contact
122
patellar contact when knee is 90 deg flexion
superior portion in contact
123
patellar contact when knee is 135 deg
more contact on odd facet than lateral
124
what is insall-salvati index
ratio of length of patellar tendon to length of patella
determiens patellat heigh
125
insall-salvati index 1:1
nromal
126
insall-salvati index >1.2
patella alta
127
insall-salvati index <0.8
patella baja
128
movement of patella in x-axis
patellar flexion and extension
129
movement of patella in y-axis
medial and lateral tilting
130
movement of patella in z-axis
medial and lateral rotation
131
discuss patellofemoral joint stress in not flexed much
compressive force is shorter
132
discuss patellofemoral joint stress as flexion increases
lie in deep squat = excessive comprresion = patelofemoral joint syndrome
133
discuss patellofemoral joint instabillity
frontal plane instbability in full ext - bcs of lateral pull of quads and ITB tas weak VMO
134
where is PFPS felt during WB
deep flexion
135
where is PFPS felt during NWB
terminal extension - due to contraction of quads
