Session 4.1 Osteology of the distal femur , patella , tibia and fibula Flashcards
1
Q
What makes up the knee joint ?
A
1) patella
2) distal femur
3) proximal tibia
2
Q
What are the two femoral condyles called ?
A
Medial and lateral
3
Q
Which femoral condyle is larger - the medial or the lateral ?
A
The medial condyle is larger because more weight goes through the medial condyle than the lateral one.
4
Q
Where on the distal femur does the patellar reside in ?
A
- on a shallow depression called the trochlear/ patellofemoral groove.
5
Q
Is it the lateral or medial lip of the trochlear/patellofermoral groove which is more prominent ?
A
The lateral lip is more prominent because it helps to resist patellar dislocation as the patellar tends fo want to move in the lateral direction.
6
Q
On the posterior side of the distal femur , what is the notch called ?
A
Intercondylar fossa
7
Q
Does the fibula make up the knee joint ?
A
No
8
Q
What makes up the proximal surface of the tibia ?
A
1) medial condyle
2) lateral condyle
3) intercondylar area ( non articular area in between the lateral and medial condyle) - at the centre of the this area there is the ‘ intercondylar eminence’
9
Q
What is the main function of the intercondylar area ?
A
Attachment for ligaments
10
Q
What is the largest sesamoid bone in the body ?
A
Patella
- this resides within tendons
11
Q
What is menisci and what is its anatomy ?
A
ANATOMY :
C shaped plates of fibrocartilage that lays between the tibia and the distal femur.
Has a thicker periphery
Attached to the intercondylar area of the tibia
Connected anteriorally by the transverse ligament of the knee
12
Q
What is the medial meniscus attached to ?
A
Medial collateral ligament
13
Q
What is the function of the menisci?
A
1) act as a shock absorber
2) deepens the surface of articulation
14
Q
What are the ligaments classified into - the ones involved in the knee joint ?
A
1) intra capsular - cruciate ligaments
2) extra capsular - collateral ligaments
3) ligaments that strengthen the capsule - oblique popliteal ligament
15
Q
What are the two cruciate ligaments called ?
A
1) anterior cruciate ligaments ( ACL)
2) posterior cruciate ligaments ( PCL)
16
Q
PAMs APples
A
Posterior passes anterior inserts medial.y ( PCL)
Anterior passes posterior inserts laterally ( ACL)
17
Q
Which is weaker of the two cruciate ligaments ?
A
ACL
because it has a relatively poor blood supply
18
Q
What is the function of the ACL ?
A
- during running the tibia often moves anterior to the femur. The ACL prevents the tibia moving far too forward relative the to distal femur.
19
Q
What is the function of the PCL?
A
Prevents excessive posterior movement of the tibia relative to the femur.
20
Q
Where is the joint capsule of the knee mainly located?
A
- surrounds the sides and posterior aspect of the joint
- it is deficient anteriorly
21
Q
How is the joint capsule in the knee strengthened laterally and medically ?
A
By inferior fibres Kd the vastus lateralis and medialis
22
Q
How is the joint capsule strengthened posteriorally?
A
Oblique popliteal ligament which is an expansion of the semimembranosus
23
Q
What are the two extra capsular ligaments called ?
A
1) medial collateral ligament
2) lateral collateral ligament
24
Q
What is the function of the medial collateral ligament ?
A
Resists valgus forces on the tibia
VaLgus = L for lateral
25
Describe tha anatomy of the medial collateral ligament
The medial collateral ligament attaches to the medial femoral epicondyle to the tibia.
- it also attaches to the medial meniscus at its midpoint.
26
Describe the anatomy of the lateral collateral ligament
Attaches to the lateral femoral epicondyle to the lateral surface of the fibula head.
27
What is the function of the lateral collateral ligament ?
Resists varus force on the tibia ( varus= medial)
28
How many bursae are found in the knee joint ?
6
29
Name the 6 bursae found in the knee joint
1) suprapatellar
2) prepatellar
3) superficial ( subcutaneous) infrapatellar
4) deep infrapatellar
5) semimembranous
6) subsartorial
30
What is the function of bursae?
- they are fluid filled sacs located around a joint that cushions bones when muscles , tendons or skin rub against the bone.
- they are very important in the movement of bones because they reduce friction,
31
What muscles in the leg aid with flexion of the knee ?
Hamstrings muscles - biceps femoris , semi membranous, semitendinosus
- this is assisted by gracilis , sartorius , popliteus , gastrocnemius
32
What muscles help with extension of the knee ?
Quadriceps muscles ( there are 4) = recurs femoris, vastus medialis, vastus lateralis, vastus intermedius
33
What joints does the recurs femoris cover ?
The hip and knee joint
34
What innerverts the quadriceps muscles ?
Femoral nerve
35
Where does the recurs femoris insert into ?
Tibial tuberosity via the patella tendon
36
When the knee is flexed , some rotation can occur - what aids medial rotation ?
1) semitendinosus
2) semimembranosus
3) gracilis
4) sartorius
5) poplitues
37
When the knee is flexed, some rotation can occur. What aids lateral rotation of the knee ?
Bicep femoris
38
Which muscle that forms part of the knee joint , has a very important stabilising effect ?
Inferior fibres of vastus medialis called the vastus medialis obliquus ( obliquus genus).
39
Outline the mechanism of locking the knee
Occurs during extension of the knee.
- the femur rotates internally by 5 degrees.
- the cruciate ligaments tighten
- the knee becomes more solid and thigh and leg muscles can relax briefly without instability
40
Outline the mechanism of unlocking the knee
Poplitues contracts and rotates femur externally
41
How can the borders of the femoral triangle be remembered?
SAIL
S = sarotorius ( lies on the lateral border of the femoral triangle)
A= adductor longus ( medial border of the femoral triangle );
I = inguinal
L = ligament
42
What are the contents of the femoral triangle ?
N~ femoral nerve
A ~ femoral artery
V ~ femoral vein
E ~ empty space
L ~ lymphatics
GOES IN ORDER
43
What makes up the femoral canal?
Empty space and lymphatics
44
Where can you feel the femoral pulse ?
Felt at mid-inguinal point
- midpoint between the anterior superior iliac spine and pubic symphysis
- just inferior the to the inguinal ligament
- blood can be taken from the fermoral vein or artery.
45
How can you tell the difference between the posterior and anterior surface of the femoral shaft ?
On the posterior surface , there is a roughened ridge of bone called the line of aspera.
46
Proximal , what does the medial border of the linea aspera become ?
The pectineal line
47
Priximally, what does the lateral border of the linea aspera become ?
Gluteal tuberosity - where the gluteas maximus inserts
48
Distally , the linea aspera widens and the medial and lateral borders form .....
Medial and lateral supracondylar lines
49
What does the more prominent lateral femoral condyle help to prevent ?
Lateral displacement of the patella .
- people with a flatter lateral femoral condyle are more likely to experience patellar instability
50
Where does the ACL attach ?
The anterior cruciate ligaments attaches to the medial aspect of the LATERAL femoral condyle.
51
Where does the PCL attach to ?
The posterior cruciate ligament attaches to the lateral aspect of the MEDIAL femoral condyle.
52
What is the superior aspect and inferior aspect of the patella attached to ?
The superior aspect is attached to the quadriceps tendons and it’s inferior aspect is attached to the patellar ligament.
53
The apex of the petalla is situated inferiorlu or superiorly ?
Inferioroly
54
What does the patella ligament connect the patella to ?
The tibial tuberosity
55
What are the two facets called which help the posterior surface of the patella articulate with the femur ?
1) medial facet : articulates with the medial condyle O.F. the femur
2) lateral facet : articulates with the lateral condyle of the femur.
56
What are the functions of the patellla ?
1) protection : protects the anterior aspect of the knee joint from physical trauma.
2) it enables the quadriceps muscle to directly cross the anterior aspect of the knee and by acting as a fulcrum , the patella enhances the leverage that the quadriceps tendon can exert on the femur - increasing mechanical efficiency by 33-50%.
3) it reduced frictional forces between the quadriceps and the femoral condyles during extension of the leg.
57
What does the head of the fibula articulate with ?
Articulates with the proximal tibia at the proximal tibiofibular joint . This does not form part of. The knee joint,
.
58
What does the tibial platue articulate with ?
The condyles form a flat surface known as the tibial plateau - this articulates with the femoral condyles to form a major articulation of the knee joint.
59
Where is the insertion site of the patellar ligament ?
Tibial tuberosity
60
What is the main ffunction of the fibula ?
It’s main function is to act as an attachment for muscles - rather than weight bearing.
61
What are the 3 main articulations sof the fibula ?
1) proximal tibiofibular joint : articulates with the lateral condyle of the tibia.
2) distal tibiofibular joint : articles with the fibular notch of the tibia
3) ankle joint : articulates with the talus bone of the foot.
62
What type of joint is the knee joint ?
Hinge type synovial joint - which mainly allows for flexion and extension with a small degree of lateral and medial rotation.
.
63
What are the two articulations that form the knee joint ?
1) patellofemoral: the patella articulates with the femur at the trochlear groove
2) tibiofemoral: the medial and lateral condyles of the femur articulate with the medial and lateral tibial condyles. ( weight bearing joint of the knee)
64
What tendon does the patellar reside in ?
Quadriceps femoris tendon
65
Where does the knee joint get their blood supply ?
Through the genicular anastomoses around the knee which are supplied by the genicular branches of the femoral and popliteal arteries.
66
If the popliteal artery which supplies blood to the knee gradually becomes occluded , what happens ?
The genicular anastomoses can dilate to main blood supply to the leg
67
The knee joint is inherently unstable , to improve stability ....
1) the tibial articular surface is depended by the menisci
| 2) the joint is supported by the joint capsule , ligaments and surrounding muscle.
68
What are the two functions of the menisci ?
1) depend the articular surface of the tibia , increasing the stability of the joint
2) act as a shock absorber by increasing surface area.
69
What happens in there is damage to the medial collateral ligament ? - what also tears
The medial me is all tears.
70
Why is the lateral collateral ligament fairly mobile - in comparison to the medial collateral ligament ?
Because the lateral collateral ligament is not attached to the lateral menisci of the knee,
71
How are th menisci connected to eachother anterioly?
By the transverse ligament of the knee
72
Why is it difficult for the menisci to heal after trauma ?
- the central meniscus is avascular by adulthood
73
During extension of the knee , the patella naturally tries to be displaced laterally . What are a few factors that help to resist this lateral vector ?
1) the deep trochlear groove which has a more prominent lateral femoral condyle anterioly.
2) the fibres of the the vastus medialis obliquus ( VMO) which are inserted more ditslly into the patella and more horizontally than those of the vastus lateralis. Contraction of these fibres resists the lateral displacement of the patellar
74
What are three compartments of the thigh
1) anterior
2) posterior
3) medial
75
The muscles in the anterior compartment of the thigh are mostly innervated by which nerve ?
Femoral nerve ( L2-L4)
76
Iliopsoas
Consists of two muscles - the spoas major and the iliacus
77
Where does the psoas major originate?
Originates from the transverse processes of the aT12-L5 vertebrate and the lateral margins of the intervertebral discs between them.
78
Where does the iliacus originate from ?
The iliac fossa O.F. the pevis
79
What innerverts the psoas major ?
Anterior rami of L1-L3
80
What innerverts the Iliacus?
Femoral nerve
81
What are the actions of the iliopsoas?
Flexed the lower limb at the hip joint and assist in lateral rotation of the femur at the hip joint.
82
What does the quadricep femoris consist of ?
1) rectus femoris
2) vastus medialis
3) vastus lateralis
4) vastus intermedius
83
The muscles that form the quadricep femoris u tie proximal to the knee joint and insert onto the base of the patella via ....
The quadricep tendon.
84
Vastus lareralis location
Originates from the greater trochanter and the lateral lip of the line of aspera
- it inserts via the quadricep tendon into the base of the patella
85
What is the action of the vastus lateralis and the innervation ?
1) femoral nerve inner ages
| 2) vastus lateralis extends the knee joint and stabilises the patellar.
86
Location of the vastus intermedius
Vastus intermedius originates from the anterior and lateral surfaces of the fedora shaft and inserts into the base of the patella via the quadricep tendon
87
Action of the vastus intermedius and innervation
Extends the knee joint and stabilises the patella
Femoral nerve innervate
88
Location of the vastus medialis
Originates from the intertrochanteric line of the femur and medial lip of the linea aspera.
- it inserts into the base of medial aspect of the patella via the quadriceps tendon.
- inferior fibres are orientsted horizontally and are known as vastus medialis obliqus (VMO)
89
Function of the vastus medialis
Vastus medialis extends the knee joint and stabilises the patellar.
- contraction of the VMO resists the lateral displacement of the patellar.
90
Innervation of the vastus medialis
Femoral nerve
91
Location of recurs femoris
- oringintes as two tendons ( the anterior tendon arises from the anterior inferior iliac spine , the posterior tendon arises from the acetabulum.
- the two unite inserting into the base of the patella via the quadriceps tendon.
92
Action of recurs fmeoris
- only muscle of the quadricep to cross both the hip and knee joint.
- it flexes they thigh at the hip joint and extends the leg at the knee joint.
- innervated by the femoral nerve.
93
Longest muscle in the body
Sartorius
94
Location of sartorisu
Originates from the anterior superior iliac spine and attaches to the medial aspect of the proximal tibia.
95
Action of sartorius
HIP JOINT: flexes , abducts, externally rotates the thigh,
KNEE JOINT : flexes and internally rotates the tibia at the knee joint.
96
Innervation of the sartorius
Femoral nerve
97
Action of pectinus.
Abducts and flexes the thigh at the. Hip joint
Innervation by the femoral nerve.
98
Where anatomically is the femoral triangle located ?
Proximal region of the anterior thigh.
99
What are the three borders of the femoral triangle
1) superior border : formed by the inguinal ligament.
2) lateral border : formed by the medial border of the sartorius muscle.
3) medial border : formed by the medial border of the adductor longus muscle.
100
Adductor longus location
Forms the medial border of the femoral triangle - it originates from the pubis - attaching to linea aspera.
101
Action of adductor longus
Abducts the thigh
102
Innervation of adductor longus
Obturator nerve
103
Location of gracilis
- most superficial + medial muscle in medial compartments thigh.
- crosses both hip N knee joint.
- originates from pubic ramus + body of pubis ,
Descends almost vertically down the medial thigh , it inserts onto the medial surface of the proximal tibia .
104
Action of the gracilus
Addictions of the thigh at hip joint and flexes the leg at the knee.
105
Innervation of the gracilis
Obturator nerve
106
Muscles that make up the anterior compartment for the thigh
- posoas major
Iliacus
Rectus femoris
Vastus medialis
Vastus lateralis
Sartorius
Pectineus
