201 L8 Flashcards
Tissues under load
What are the 4 basic structures of all synovial joints?
Articular cartilage at the ends of bones.
Articular capsule
Joint cavity
Synovial fluid
What structure of the synovial joint is described below?
Fibrous layer holding bony ends together, has blood vessels,
nerves and synovial membrane lining the
articular cartilage
Articular capsule
What makes a synovial joint Complex?
Menisci
What are menisci?
Fibrocartilaginous discs in the joint space,
What makes a synovial joint a compound joint?
A joint is compound when it has more than 2 articular surface interaction.
Classify what the knee joint is?
Both a complex and a compound joint
What are the lower limb/leg joints?
Hip, knee and ankle
The thigh is the section between the —- and —–.
The thigh is the section between the hip and knee.
The leg is the section between the —– and —–.
The leg is the section between the knee and ankle.
What are the 3 bones that form the skeletal structure of the knee joint?
Femur (thigh -biggest bone)
Tibia
Patella
The patella is a ——- bone.
Usually found inside the tendons of ——— where the tendon runs over
something hard. The bone protects the ——– and gives mechanical advantage.
Born with it so is recognised as an independent bone.
The patella is a sesamoid bone.
Usually found inside the tendons of muscle where the tendon runs over
something hard. The bone protects the tendon and gives mechanical advantage.
Born with it so is recognised as an independent bone.
Is the fibula part of the knee joint? Why?
No because it is not directly involved with any articulation at the knee.
How many articulating surfaces are there within the knee?
What does this suggest about the joint?
3 articulating surfaces
Suggests the knee is a compound joint.
What are condyles?
Curved (convex or concave) articulated surfaces of bones that are in contact with each other.
What are the 3 joints formed by the 3 articulating surfaces in the knee joint?
Lateral tibio-femoral joint
(Between the tibia and femur on the lateral side)
Medial tibio-femoral joint
(Between the tidia and femur on the medial side)
Patella - femoral joint (between the patella and femur)
What two joints of the knee are found between condyles?
Lateral and medial tibio-femoral joints
What aspect of the knee is the patella femoral joint at?
The anterior aspect
Are the condyles at the distal end of the femur concave or convex?
Convex
Are the condyles at the tibia concave or convex?
Convave
Name the 4 condyles in the knee joints?
Convex
Lateral femural condyle
Medial femural condyle
Concave
Lateral tibial condyle
Medial tibial condyle
If you cut the patella away from your knee joint and look at the ———– side of the
knee joint its got a _-shaped ——– surface that complements the ———-
surface of the ——– called the ———- surface.
If you cut the patella away from your knee joint and look at the posterior side of the knee joint its got a v-shaped articular surface that complements the anterior
surface of the femur called the patellar surface (Trochlea).
What is the function of the patella?
Prevents the muscle that is used to extend our knee from slipping around the sides, so insures that it is carried on the front.
The ——– ——– of the knee is large and very complex.
Articular capsule
Knee joint
The ———- lining is very extensive, folding into the —— and surrounding ——structures.
The synovial lining is very extensive, folding into the joint and surrounding joint structures
The knee joint has ———— pads/ ———— inside the joint making it a ——– joint.
The ———– layer incorporates many of the ———- and ——— needed to stabilise the joint.
It can ——– better than articular cartilage but it’s really strong for movement.
The ———— of the femur and the tidia don’t actually fit against each other very well
The knee joint has fibrocartilaginous pads/meniscus inside the joint making it a complex joint.
The fibrous layer incorporates many of the ligaments and tendons needed to stabilise the joint.
It can deform better than articular cartilage but it’s really strong for movement.
The condyles of the femur and the tidia are not very congruent, they don’t actually fit against each other very well
What determines the movement of the knee?
What do these determinants restrict?
The shape of the articulating surfaces and the limitations of ligaments.
These two aspects restrict knee flexion/extension and rotation.
When can rotation of the knee occur?
Rotation can only occur when the knee is flexed (loose-packed)
What is a fossa?
A depression in the bony surface?
Name the fossa of the knee joint
Where is it located?
Intercondylar fossa
Between the medial and lateral condyles
What is an eminence?
High protruding piece of bone
Name the eminence of the knee joint
Intercondylar eminence
What two aspects of the knee joint are important for movement?
Intercondylar fossa and eminence.
What is a feature of the knee that indicates that you are looking at the anterior side?
The patella
Is the femur superior or inferior to the tibia?
The femur is superior to the tibia
Is the fibula the lateral or medial bone?
Lateral bone - its on the outside of the leg.
Is the tibia medial or lateral?
Medial
If you cant see the fibula than it must be on the other side. The fibula is always on the ——- side of the knee, so the absence indicates that you are looking at the ——- side of the knee.
If you cant see the fibula than it must be on the other side. The fibula is always on the lateral side of the knee, So the absence indicates that you are looking at the medial side of the knee.
If you are looking at the anterior view of the knee and the fibula is the the left of the tibia than this is the ——– leg.
Right
If you are looking at the anterior view of the knee and the fibula is the the right of the tibia than this is the ——– leg.
Left
Sagittal plane divides the body into —– and ——– sides.
Left and right
When you flex your knee you are bringing the —— surface closer to the ——— surface.
When you flex your knee you are bringing the posterior surface closer to the posterior surface.
What limits the angle of flexion?
Soft tissue
Are femoral or tibial condyles larger?
Femoral
Movement of the joint
If we allowed the femur to roll on the surface of the tibia freely when ——– and ——— occurs the ——– would just ——– right off the back of the ———-.
This is because the ——— condyles are larger than the ——- condyles.
If we allowed the femur to roll on the surface of the tibia freely when flexion and extension occurs the femur would just roll right off the back of the joint.
This is because the femoral condyles are larger than the tibial condyles.
Movement of the joint
When you —— and —— your knees there is a combination of ——— and ——— movement so you need something to stop the —– from rolling off.
Therefore we don’t want —— and ——- movement. The ———– ———– interlocks with the ———– ———– allowing the bones to slide ——– and ——–, but not ——— and ——-. This interaction also allows the femur and tibia to ——– in relation to each other, allowing movement in the ——— plane along the ———- axis.
When you flex and extend your knees there is a combination of linear and angular movement so you need something to stop the femur from rolling off.
Therefore we don’t want medial and lateral movement. The intercondylar fossa interlocks with the intercondylar eminence allowing the bones to slide anterior and posterior, but not medial and lateral. This interaction also allows the femur and tibia to rotate in relation to each other, allowing movement in the transverse plane along the longitudinal axis.
Knees can’t move in the —— plane around an
______-______ axis
Knees can’t move in the frontal plane around an anterior-posterior axis
What is abduction and Adduction?
If you move the distal structure away from the midline it is referred to as abduction
If you move the distal structure closer to the midline it is referred to as adduction
What prevents the knee from undergoing abduction and adduction?
The two points of contact between the condyles
The medial and lateral collateral ligaments.
What ligament prevents adduction of the tibia?
Lateral (fibular) collateral ligament
What ligament prevents abduction of the knee joint?
Medial (tibial) collateral ligament
Supporting ligaments
Ligaments are made of dense ———– tissue with a specialised role of connecting ——–.
Their main purpose is the help distribute ——– loads to other structures within the ——-.
They are important for controlling the ——— of ——– motion by preventing abnormal ——– or —— that could damage the joint.
Ligaments are made of dense connective tissue with a specialised role of connecting bones.
Their main purpose is the help distribute tensile loads to other structures within the joint.
They are important for controlling the limits of joint motion by preventing abnormal displacement or rotation that could damage the joint.
What are extracapsular ligaments?
ligaments that occur outside the articular capsule
What are capsular ligaments
Ligaments that form part of the outer fibrous layer of the articular capsule
What do the extracapsular and capsular ligaments
Holding the articulating bones together and stabilising the
joint throughout its movement
The ——- collateral ligament reinforces the medial surface of the knee joint by joining the —– to the ——. It runs from the ——– condyle on the —— side to the ——-.
This is a ——— ligament that stops ———– at the knee joint.
The ——- collateral ligament reinforces the lateral surface of the knee joint by joining the —– to the ——.
This is a ——— ligament and in parts is ———. It stops ———– at the tibia.
The tibial collateral ligament reinforces the medial surface of the knee joint by joining the femur to the tibia. It runs from the femoral condyle on the medial side to the tibia.
This is a capsular ligament that stops abduction at the knee joint.
The fibula collateral ligament reinforces the lateral surface of the knee joint by joining the femur to the fibula.
This is a capsular ligament and in parts is extracapsular. It stops adduction at the tibia.
Patella complex
There are —— ——- coming down at the front of the knee called ———- which converge onto the ———. It pulls the ——- in multiple
directions so to help the patella ligament they may have these strap like structures called patella ————
Can look at this as a group of muscles coming down and attaching to the ——- bone and this bone is attached to the —— via a ———.
Or can look at this as a big muscle coming down and there is a ——– attaching to the —— with the ——- bone buried in the tendon.
There are 4 muscles coming down at the front of the knee called quadriceps which converge onto the patella. It pulls the patella in multiple
directions so to help the patella ligament they may have these strap like structures called patella retinaculum.
Can look at this as group of muscles coming down and attaching to the patella bone and this bone is attached to the tendon via a ligament.
Or can look at this as a big muscle coming down and there is a tendon attaching to the tibia with the patella bone buried in the tendon
When do the collateral ligaments operate?
Only when the knee is in full extension.
What major complex supports the anterior aspect of the knee joint?
Patella complex
Patella quadriceps tendon and extensor muscles
patella
patella ligament + patella retinaculum)
What attaches the patella to the tibia/tibial tuberosity?
Patella ligament
What are intracapsular ligaments of the knee?
Anterior cruciate ligament
Posterior cruciate ligament
Where are the intracapsular ligaments of the knee found?
Inside the acticular capsule - In the intercondyle fossa
What are the intracapsular ligaments of the knee covered with?
They are covered with synovial membrane that is continuous from the lining
of the articular capsule.
What is the purpose if the anterior cruciate ligament?
Prevents forward gliding of the tibia in relation to the femur and knee hyperextention.
What is the purpose if the posterior cruciate ligament?
Prevents backward
gliding of the tibia in relation to the femur.
Both cruciate ligaments maintain the alignment of the ——- and ——– condyles during ——- and ———-.
Because the ——— cruciate is attaching to the front of the tiba and the back of the femur it stops the dislocation of the femur ———- in relation to the —— or prevents ——- dislocation of the tibia in relation to the femur
Because the ———- cruciate is attaching to the back of the tibia and the front of the femur it prevents ——– displacement of the femur in relation to the tibia or ———- displacement of the tibia in relation to the femur
Both cruciate ligaments maintain the alignment of the femoral and tibial condyles during flexion
and extension.
Because the anterior cruciate is attaching to the front of the tibia and the back of the femur it stops the dislocation of the femur posteriorly in relation to the tibia or prevent anterior dislocation of the tibia in relation to the femur
Because the posterior cruciate is attaching to the back of the tibia and the front of the femur it prevents anterior displacement of the femur in relation to the tibia or posterior displacement of the tibia in relation to the femur
When you are ———- you are burning energy and you want the two bones to be in —— with each other
When you don’t want to burn as much energy when you are standing you can move the ——- forward about — degrees, putting the ——— ligaments and ———- under a lot of strain so you are using ———– stabilization.
If you go over —– degrees up to —– degrees you will rupture the ——– cruciate.
If it goes over — degrees you are going to lose all the ——-.
When you are standing you are burning energy and you want the two bones to be in line with each other
When you don’t want to burn as much energy when you are standing you can move the femur forward about 10 degrees, putting the collateral ligaments and cruciates under a lot of strain so you are using passive stabilization.
If you go over 10 degrees up to 30 degrees you will rupture the anterior cruciate.
If it goes over 30 degrees you are going to lose all the cruciates
Describe a procedure for ACL reconstruction?
Graft - ligament and bone from patella and tibia.
or
Harvest hamstring tendons but there is no bone on bone mending
Drill up from the front of the tibia and to the lateral side of the femoral condyle and thread that piece of ligament through the holes and anchor it with screws
———– provide a passive method of stabilising the knee.
They are most effective when they
are placed under ——– at certain joint positions (———- knee = ‘close-packed).
When the position of the knee is not placing the ligaments under ——— (___-_____ knee), the ligaments
tend to be slack or ——–. In this state the knee is more susceptible to ——— or unwanted movement.
Ligaments provide a passive method of stabilising the knee.
They are most effective when they are placed under tension at certain joint positions (extended knee = ‘close-packed’).
When the position of the knee is not placing the ligaments under tension (mid-flexed knee), the ligaments tend to be slack or loose. In this state the knee is more susceptible to dislocation or unwanted
movement.
Because ———- are attached to muscle, they can be placed under ———- at almost any position of the knee.
This ——— stabilisation of the knee by the muscles and their ——- can help protect the knee when the ————- are loose.
Because tendons are attached to muscle, they can be placed under tension at almost any position of the knee.
This active stabilisation of the knee by the muscles and their tendons can help protect the knee when the ligaments are loose.
Name the flexor and extensor muscles of the knee
Extensor = Quadriceps
Flexor
Biceps femoris
Semitendinosus
Semimembranosus
Name the muscles that make up the quadriceps.
Rectus femoris
Vastuc intermedius
Vastus lateralis
Vastus medialis
What is the most superficial quadricep muscle?
Rectus femoris
What is the strongest quadricep muscle?
Vastus medialis
What quadricep muscle is underneath the rectus femoris?
Vastus intermdius
Where do the quadricep muscles insert?
Patella
Where does the biceps femoris insert?
Lateral side of tibia and head of fibula
Where does the Semimembranosus muscle insert?
medial side of the tibia
Where does the Semitendinosus muscle insert?
medial side of the tibia
Name the hamstring muscles.
Semimembranosus
Semitendinosus
Biceps femoris
