Lecture 8 Flashcards
What is the largest joint in the body?
The Knee
- in some ways is also the most complicated joint in the body
- is quite frequently injured
What two articulations compose the Knee Joint?
- articulation b/w Femur & Tibia
+ - articulation b/w Femur & Patella(Knee Cap) - Patellofemoral joint
- the knee joint has a joint space with the femur
What is the Patellofemoral Joint?
articulation between the Patella and Femor
- one component of the Knee Joint
2. articulation between Femur & Tibia
What 2x things does the articular cavity of the knee include?
- Patellofemoral Joint
2. Tibiofemoral Joint
What are the 2x key mechanisms surrounding the Knee Joint and Movement?
- Big Hinge joint - that allows mainly flexion and extension
- Locking Mechanism : when knee is fully extended, there is a decrease in energy required to maintain a straight leg - i.e. when standing or walking
What is the Locking Mechanism of the Knee?
When your knee is fully extended, there is a decrease in the energy required to maintain a straight leg (i.e. when standing or walking)
What are the main movements of the knee joint?
Mainly Flexion and Extension
-as is a Big Hinge joint essentially
What sort of bone is a Patella, and what are its corresponding features?
sesamoid bone: a bone that lives Within the tendon
-there are sesamoid bones in wrist and feet
Made into sesamoid bone by Patellar Ligament (continuation of quadriceps mechanism)
Function to Protect the tendon:
patella is articulating/rubbing over the femur, and protects the tendon from Femur
- would wear through and rupture really fast
(bone-on-bone»_space; obviously alot stronger than tendon-on-bone)
Where do the quadriceps attach to the knee?
Anteriorly and Inferiorly
onto boney ridge = Tibial Tubercle
-necessary for knee Extension (if insertion was above patella wouldn’t be able to extend/carry out its function)
What mechanism is the Patella part of?
Quadriceps Mechanism
Main stabiliser of the Knee
initial part of rehab for someone with injured knee
-normally sufficient rehab to return back to a functioning knee
What is the Patella Alignment?
Line of pull of Quadriceps = pulls patella slightly Laterlal Boney anatomy (lateral condyle) stops patella from dislocating laterally -Lateral Condyle (flexed distal femur) projects Further Forward than medial condyle (Femur is different on either side distally to stop patella from dislocating laterally)
What is the boney anatomy of the distal femur like?
Lateral Condyle projects further forward, in order to stop patella from dislocating laterally (due to the pull of the quadriceps)
What does Cruciate mean?
cruciate = “cross”
2x ligaments locate DEEP inside the knee
Stability of the Knee in AP plane– Very Important
Both originate Deep from the internal aspect of Femoral Condyles
Both insert onto superior aspects of the Tibia onto the Tibial Spine/Intercondylar Region of Tibia (Anterior/Posterior Tibial spine)
Posterior C.L: stops tibia from sliding backwards - walking down stairs, allows you to stabilise knee joint, to load a flexed/partially bent knee
Anterior C.L: stops Excessive Anterior Translation/tibia sliding forwards when Walking = common activity therefore Really important
Cruciate Ligaments are WITHIN knee Joint, but OUTSIDE of articular cavity
What is the function of the Posterior C.L?
Posterior Cruciate Ligament
Posterior Tibial spine –> Medial Femoral Condyle
Stops the Tibia from sliding backwards/posteriorly (on the femur)
Walking down stairs
STABILISEs knee joint
allows you to Load off a partialy bent/flexed knee
What stabilises the knee and allows you to load off a partially bent/flexed knee?
Posterior C.L Cruciate Ligament
What is the function of the Anterior C.L?
Anterior Cruciate Ligament
Anterior tibial spine –> Laterla Femoral Condyle
Stops Excessive Anterior Translation/ tibia sliding forward onto Femur during walking
When Walking –> therefore really important
What is the main function of both Anterior and Posterior Cruciate Ligaments?
Stability of the knee in the AP plane
What is the Deep/underside surface of the Patella covered with?
Articular cartilage
-so it can move on the Femur
What is articular cartilage located on the patella?
Knee Cap
Deep/Underside surface of the Patella
so that it can move on the Femur
What is another name for the Tibial spine and what is located there?
Intercondylar region of the tibia
=tibial spine
Anterior and Posterior cruciate ligaments originate from there
What is the origin and insertion for both the anterior and posterior Cruciate Ligament?
- Anterior Cruciate Ligament
Anterior Tibial spine –> Medial Condyle - Posterior Cruciate Ligament
Posterior Tibial Spine –> Lateral Condyle
(technically Anterior intercondylar region /Posterior intercondylar region)
Within Knee Joint
Outside of Articular Cavity
What is the location of the cruciate ligaments?
Inside Knee Joint
Outside Articular Cavity
Are the cruciate ligaments inside or outside of the articular cavity?
Outside Articular cavity
Inside Knee Joint
What is the Patellar Ligament?
continuation of quadriceps mechanism
-Makes the patella a sesamoid bone
Superior attachment: Inferior margins of Patella
Inferior = Tibial Tuberosity
What are the Superior and Inferior attachments of the Patella Ligament?
Superior attachment= Inferior margins of Patella
Inferior Attachment = Tibial Tuberosity
What is the Patella ligament a continuation of and what is its relationship with the patella?
Patella ligament is a continuation of Quadriceps Mechanism
Makes Patella into a sesamoid bone
What are the 2x knee alignments?
- Varus = Bow Legged (older people)
2. Valgus = Knock kneed
What is the knee alignment called for people who are knock-kneed?
Valgus align.
What is the knee Alignment called for people who are bow-legged?
Varus Align.
What are essential features of the Collateral Ligaments?
attached to the side of the need (“co”=paried “lateral”=to the side”)
MCL = Medial Femoral epicondyle –> Medial Tibia (posterior to Pen Anserinus attachment) -Broad, blends into underlying joint capsule
LCL = Lateral femoral epicondyle –> Fibula head. Cord like. Discrete from joint capsule
Medial (tibial) Colateral Ligament MCL
Gives sideways stability to knee joint
Medial Femoral Epicondyle –> Medial Tibia
runs more Posteriorly
Injured more regularily, and occurs to all 3x components which fuse
Posterior to Pes Anserinus attachment
Broad ligament
Blends with the Joint capsule
Lateral (fibular) Co-Lateral Ligament LCL
Gives sideways stability to knee joint Lateral Femoral Epicondyle --> Fibular head Cord like ligament Discrete from joint capsule Relatively strong
Which co-lateral ligament is broad?
MCL Medial Co-lateral Ligament
Which co-lateral ligament is attached to the Medial Tibia?
MCL Medial Co-lateral Ligament
Which co-lateral ligament is cord-like?
LCL Lateral Co-lateral Ligament
Which co-lateral ligament is posterior to Pes Anserinus?
MCL Medial Co-lateral Ligament
Which co-lateral ligament is is attached to fibula?
LCL Lateral Co-lateral Ligament
Which co-lateral ligament is discrete from Joint Capsule?
LCL Lateral Co-lateral Ligament
What are the essential features of a Bursa?
potential space -soft tissue (can expand) water balloon (pocket full of fluid) where 1. Muscles runs over bone 2. areas of high friction -can rub from side to side, and IT will move so that whatever is underneath it Doesnt get stuck or frayed
What composition a Bursa allows it to be a “potential space”?
Soft tissue
-can expand
water balloon (pocket full of fluid)
Potential space = more friction = more pressure applied to it = will create more fluid = will become larger
enlarged = problematic
What are the names of the 4x Bursa’s located around the knee (Patellar Bursas)?
- Suprapatella Bursa
- Prepatellar Bursa
- Infrapatellar Bursa
What are the main features of the SupraPatellar Bursa?
More important
Deep to quads tendon
Between Quads Tendon and Distal Femur
allows quads tendon and distal femur to rub against each other freely
CONTINUOUS with joint capsule itself
therefore the suprapatellar joint FLUID is the same as with what is in the joint space
Knee aspirate - is hard to get fluid from knee joint (b/w femur and tibia) 4x reasons.
1. Joint space is small space
2. very painful if the needle hits the bone (joint spaces b/w tibia and femur)
3. Smooth muscle can expand ( + soft tissue and fluid collecting inside) - Needle into soft tissue and muscle MUCH LESS PAINFUL
4. can Gently slide in through smooth muscle
Also often a place where Fluid will accumulate during a knee joint effusion
Which patella bursa is continuous with the joint space of the knee?
Supra-patellar Burse
What is the Supra-patellar bursa an ideal location for?
Knee Aspirate
What 4x reasons make the Supra-patellar bursa an ideal location for a Knee Aspirate, instead of from the Knee Joint?
is hard to get fluid from knee joint (b/w femur and tibia) 4x reasons.
- Joint space is small space
- very painful if the needle hits the bone (joint spaces b/w tibia and femur)
- Smooth muscle can expand ( + soft tissue and fluid collecting inside) - Needle into soft tissue and muscle MUCH LESS PAINFUL
- can Gently slide in through smooth muscle
What is the function of the 2x Infra-patellar Bursae?
either side of the Patella Tendon
Can become inflamed upon excess kneeling
“Clergyman’s Knee”
What is the function of the Pre-patellar Bursa?
Anterior to Patella
Protects skin from the front of the patella, when you have friction
Potential space = more friction = more pressure applied to it = will create more fluid = will become larger
enlarged = problematic
Inflammed Prepatellar Bursa = Housemaid’s Knee
Kneeling
What does the Pre-patellar Bursa protect from?
Protects skin from the front of the patella, when you have friction
What is the name for an inflamed Pre-patellar Bursa?
Housemaid’s Knee
What is the name for an inflamed Infra-patellar Bursa?
Clergyman’s Knee
What will often happen during a knee joint effusion?
Fluid will accumulate in the Supra-patellar Bursa
When will fluid accumulate in the supra-patellar Bursa?
During a knee joint effusion
Where is the supra patellar bursa located?
B/w Quads tendon and Distal Femur
Where is the Pre-patella Bursa located?
Anterior to patella
Where is the infra-patellar bursa located?
Superficial and Deep to the Patellar ligament
Inferior to Patella iteslf
What is located superficial and deep to the patellar ligament? and what is its position relative to the patella itself?
Infra patellar Bursa
and Inferior to patella itself
What encloses the articular cavity of the knee?
fibrous capsule
What does the fibrous capsule of the knee inclose?
the articular cavity
Does fusion occur on the medial side of the knee joint capsule?
Medially Yes
MCL and medial meniscus fuse with the fibrous membrane
there medial knee injuries involve all these structures
Does fusion occur on the lateral side of the knee joint capsule?
No
LCL and lateral meniscus are not attached to the fibrous membrane
Lcolateral ligament is Discrete/not attached to the knee joint
What is reinforced by the quads tendon and patella ligament? and at what relative position?
Anteriorly the Quads tendon and Patella ligament reinforces the Fibrous membrane of the knee joint
What is the fibrous membrane of the knee joint reinforced by and where?
Anteriorly the Quads tendon and patella tendon reinforce the fibrous membrane of the knee joint
What is the relative position of the knee’s fibrous membrane and synovial membrane?
Synovial membrane is deep to the fibrous membrane
What is the relationship between the synovial membrane and anterior and posterior cruciate ligaments?
Synovial membrane EXCLUDES both cruciate ligaments (ACL and PCL)
as the cruciate ligaments ARENT part of the articular cavity
(only part of the joint capsule)
What is the relative thickness of a ligament and capsule?
Tendon thicker > joint capsule
joint capsule is slightly thinner
Is a Tendon thicker than the joint capsule or is the joint capsule thicker than a tendon?
Tendon thicker> then joint capsule
What are the Medial and Lateral menisci?
firbocartilagenous pads
located Within the knee joint
medially and laterally
What is the function of the Medial and Lateral Menisci?
Improve the articulation between Femur and Tibia
As the shape of the surfaces changes throughout the full range of motion
Relatively out of the 2x menisci located in the knee joint, which one is more mobile and why?
Lateral Meniscus = More Mobile= as is NOT attached to the joint capsule
- means LESS likely to getinjured - as can get itself out of trouble
Medial Meniscus = Less Mobile= as is adhered medially to the joint capsule and MCL Medial Colateral Ligament, therefore less mobile
-decreased mobility means has to Deal with all the Forces being Transmitted through it One at a Time
=more likely to be damaged
Structurally what are 2x of the differences in the shape and length of the 2x menisci?
- Lateral Meniscus - More Cresent or c-shaped
2. Medial Meniscus - Longer from front to back
What are the essential features of the Medial Meniscus?
- Longer from front to back
- Functions to increase the articulation between the femur and tibia as the shape of the surfaces changes over a full range of motion
- Adhered medially to the Joint capsule and MCL Medial Collateral Ligament
- Therefore less mobility = cannot move quite as much = has to deal with all of the forces being transmitted through it one at a time = more likely to get injured
What are the essential features of the Lateral Mensicus?
- Cresent / c-shaped
- Functions to increase the articulation between the femur and tibia, as the shape of the surfaces changes over the full range of motion
- ISnt adhered laterally to the lateral meniscus or LCL
- Therefore has greater mobility = can move and get itself out of trouble more (easily) = Less likely to get injured
What are the features of the meniscus in a coronal slice of a MRI scan?
Wedge shaped (in coronal plane) Thicker periphery (thinner in middle)
What is the shape of Menisci in the Coronal plane in a Coronal MRI scan?
Wedge shaped
and Thicker at Periphery
Are the Meniscus thicker or thinner in the periphery?
Thicker in Periphery
Thinner in Middle - more wear?
What is another name for the Lateral Colateral Ligament?
Fibular Colateral ligament
What is another name for the Medial Colateral Ligament?
Tibial Colateral ligament
Which is relatively stronger out of the MCL or LCL?
LCL is relatively stronger
- injured less
- not fused –> mor emobile
Is it called the Patella Ligament or Patella Tendon?
Patella TENDON
the Patella is a SESAMOID bone, which is PART of the quadriceps and its extensor mechanism
therefore there is no ligament bone-to-bone attachment
is really just a tendon, that is attached to the quadriceps in order to help it slide over the knee
What are some essential features of the Pes Anserinus?
"Gooses Foot" - when inserting Medial side of upper(proximal) tibia Gracilis + Staroius + Semitendinosus Harvest these tendons for ACL/PCL reconstruction if torn or use central portion of patella tendon
What 2x areas can be use for Harvesting and ACL/PCL reconstruction?
- Pes Anserinus
2. central portion of PAtella Tendon
What can both the Pes Anserinus and Patella tendon be used for?
Harvesting
or Repairing torn ACL/PCL Reconstruction
What is another name for Pes Anserinus?
Gooses foot
What 3x things is the Pes Anserinus composed of?
- Gracilis
- Satorius
- Semitendinosus
What is the Superior and Inferior Vascular supply to the knee, which anastomose with one another?
Superiorly:branches from 1. Femoral arteries
2. lateral femoral circumflex arteries
3. popliteal vessels
Inferiorly: branches from 1. Anterior Tibial
2. Circumflex peroneal arteries
ANASTOMOSE
What is the superior boundary of the popliteal fossa Medially?
S&S
Semitendinosus and Semimembranosus
What is the superior boundary of the popliteal fossa Laterally?
BF
Long head of Biceps Femoris
What is the inferior boundary of the popliteal fossa Medially?
MG
Medial head of Gastrocnemius
What is the inferior boundary of the popliteal fossa Laterally?
LG
Lateral head of Gastrocnemius
What are the 5x contents of the Popliteal Fossa?
Nerves:(first two branches from sciatic nerve) 1. Tibial nerve 2. Common Peroneal (fibular) Nerve Arteries: 1. Popliteal Artery 2. SSA Small Saphenous Artery Vein: 1. Popliteal vein
What is the order of the contents of the popliteal fossa from superficial to deep?
Nerve –> Vein –> Artery
Popliteal Artery is the most Anterior structure, is closest to the knee joint
Nerve is in least danger as is able to wiggle out of danger more freely from underneath the femur
What are the essential features of the Popliteal fossa?
Diamond shaped
Deep and Posterior to the Knee
contains Neurovascular Bundle
What is the risk of having the popliteal artery as the deepest structure in the knee?
Closest to the knee joint = more at risk of getting damaged = rupture/hole formed =blood leak out and into compartments =compartments syndrome -occurs POSt Operation/Surgery therefore the first check is for Dorsalis Pedis & Tibilais Anterior pulse (at foot) to check that vulnerable Popliteal Artery has ruptured/risk of compartment syndrome in popliteal fossa
What is the risk Post Knee Operation/Surgery?
Popliteal Artery is deepest in fossa/closest structure to knee Joint
therefore vulnerable and prone to tearing/rupturing
–> hole and leaking blood could lead to compartment syndrome
- Check Dorsalis Pedis pulse straight after surgery to check that this rupture hasnt occured
What is the first Checking point after/post operation Knee surgery?
Check Dorsalis Pedis Pulse
- ensures rupturing of deep/closest popliteal artery hasnt occurred
- avoiding compartment syndrome
