knee joint and thigh Flashcards
Week 12
What is the function of the patellar?
Distributes the force of the quadriceps tendon
Patellar: Lateral lip function:
keeps the patella in line with the femur during knee movements (patellofemoral tracking)
What are the two joints of the knee joint?
tibiofemoral and patellofemoral
What is the functional joint type and movements of the Tibiofemoral joint?
Type: Modified hinge joint (structurally = condyloid)
Movements:
Extension, flexion and some rotation
What is the joint type and function of the patellofemoral joint?
Functional: synovial plane joint
Movements: gliding
What is the menisci and what are its functions?
What:
Fibrocartilage wedges on the tibial plateau, articulate with femoral condyles
functions:
wedge shape improves congruity,
shock absorbs.
What are the ligaments of the knee joint?
Extracapsular:
-patellar ligament
-collateral ligaments (medial/tibial and lateral/fibular)
intracapsular
-anterior cruciate ligament (ACL)
-posterior cruciate ligament (PCL)
What is the patellar ligament?
Continuation of quadriceps femoris tendon from apex of patella –> tibial tuberosity
What is the attachment of the medial/tibial collaterol ligament?
Medial femoral epicondyle –> medial surface of tibia and blends with capsule
What is the attachment of the lateral/fibular collateral ligament?
Lateral femoral epicondyle –> head of the fibula
What is the function of the two collateral ligaments of the knee joint?
limit rotation and lateral movements of knee
taunt in extension
What are the functions of the ACL?
Taunt in extension (prevent hyperextension)
Prevent:
- posterior displacement of femur on tibia
-anterior displacement of tibia on femur
Describe the attachment of the ACL and PCL.
Both originate from the intercondylar are of the tibia and insert on the femoral condyle
ACL= anterior –> medial side of lateral femoral condyle
PLC= posterior side –> lateral side of medial femoral condyle
What is the function of the PCL?
Taunt in flexion (prevent hyperflexion)
prevents:
-anterior displacement of femur on tibia
What are the bursae of the knee joint?
Surapatella bursa
Subcutaneous prepatellar bursa
Deep and superficial infrapatella bursa
What is the function of the suprapatella bursa?
communicate with synovial cavity
What is the function of the subcutanepus prepatellar bursa?
protection during kneeling
What is the function of the deep and superficial infra patellar bursa?
Protection during movement of the quadriceps.
Steps of the Knee Locking mechanism
Flat inferior aspect of femoral condyles in contact with tibia (congruous surfaces = stable)
Medial rotation of femoral condyles on tibial plateau –> tightening of ligaments
Body’s center of gravity falls in line anterior to the knee joint –> pushing it into extension –> tightening ligaments
What muscles allow for flexion of the knee joint?
Hamstrings
Weaker flexors (Sartorius, gracilis, gastrocnemius and plantaris)
What muscles allow for extension of the knee joint?
Quadricpes femoris
what muscles allow for
Lateral rotation of the leg
Biceps femoris
What muscles allow for medial rotation if the leg?
semitendinosus and semimembranous (of hamstrings)
In what position is rotation not possible in?
Extension
contents of the popliteal fossa
Popliteal artery and vein
Tibial nerve
Common fibular nerve
boundries of the Popliteal fossa
Superomedial = semimembranosus and semitendinosus
Superolateral = biceps femoris
Inferomedial = medial head of gastrocnemius
Inferolateral = lateral head of gastrocnemius
Where does the adductor canal start and finish?
( starts at the femoral triangle and ends at the adductor hiatus)
Boundaries of the adductor canal
anteriorly by sartorius
laterally by vastus medialis
posteriorly by adductor longus and adductor magnus
contents of the Adductor canal
femoral artery
femoral vein
nerve to vastsus medialis
saphenous nerve
What does the femoral artery turn into at the adductor hiatus?
Popliteal artery and vein
Which structures attach to the medial and lateral epicondyles of the femur?
medial:
-medial collateral
- pes anserine tendon (SRT)
lateral
-LCL
-iliotibial band
what attaches at the fibula head and neck?
head
-proximal tibofibular ligament
neck
-biceps femoris tendon
-fibular collateral ligament
what muscles of the thigh play a major role in mainating dynamic stability of the knee and can be wasted if the knee is injured?
Quadriceps: mainly vastus lateralis and medialis
what stretch reflex involves the hamstrings and quadrcieps?
what are the nerve roots of this test?
patellar tendon reflex
L3 or L4
why does the transverse ligament often tear when the medial collateral ligament tears?
damage to the MCL disrupts the normal biomechanics of the knee, placing additional stress on the transverse ligament.
(forces that would normally be distributed across the MCL may be redirected to the transverse ligament)
what is the role of the transverse ligament of the knee?
tibial alignment, meniscal stability and joint stability
anterior drawer test:
what tests:
How tests:
tests: ACL stability
how:
1- patient lies on their back with the knee flexed at a 90
2- The examiner sits on the patient’s foot to stabilize it.
3- The examiner gently pulls the tibia forward in relation to the femur.
positive anterior drawer test
The tibia moves excessively FORWARDS in relation to the femur. This suggests that the ACL may be torn or partially torn.
(not a diagnosis)
what is the posterior drawer test and how is it preformed?
what:
physical examination maneuver used to assess the stability of the posterior cruciate ligament (PCL)
how:
same set up as the anterior but the examiner pushes tibia backwards in relation to the femur
positive posterior drawer test
tibia moves excessively BACKWARDS in relation to the femur. This suggests that the PCL may be torn or partially torn.
