Week 7 [not including lab] Flashcards
What is the anatomical, functional, and physiological joint type of the knee?
- synovial
- hinge
- rotation/rolling and gliding
What bones make up the knee (3)
femur
tibia
patella
List 5 structures that provide stability to the knee
- capsule
- ligaments
- menisci
- muscles
- tendons
Explain how the knee capsule provides stability?
- resists hyper extension
- provides rotational stability
List the extracapsular and intracapsular ligaments
- extracapsular: medial collateral, lateral collateral
- intracapsular: anterior cruciate, posterior cruciate
What is the role of the anterior cruciate ligament
prevents anterior displacement of the tibia on the fixed femur and prevents hyperextension
What is the role of the posterior cruciate ligament
prevents posterior displacement of the tibia on the fixed femur
Explain the role of menisci and what it is made of?
- provides cushioning and stability; increases synovial circulation
- fibrocartilage
What is the mensci attached to?
- tibial plateau
- capsule by coronary ligaments
List the muscles that make up the quadricep femoris
- rectus femoris
- vastus medialis
- vastus intermedias
- vastus lateralis
What movement is the quadriceps responsible for?
knee extension, hip flexion
List the muscles that make up the hamstrings
- biceps femoris
- semimembranosis
- semitendinosis
What movement is the hamstrings responsible for?
knee flexion, hip extension
What movement is the tensor fascia latae (TFL) responsible for?
flex and abduct thigh on trunk at hip
What movement is the gracilis responsible for?
knee flexion
What muscles provide side stability to the knee?
lateral: tensor fascia latae (TFL)
medial: gracilis
Explain the motion of the femoral condyles during flexion and extension
flexion: anterior glide and posterior roll
extension: posterior glide and anterior roll
Why is the medial meniscus more C shaped and the lateral meniscus O shaped?
he medial tibial plateau has a greater anterior posterier distance than the lateral tibial plateau
Explain what happens to the following when you lock out your knees (locking mechanism):
- ACL
- PCL
- joint capsule
- medial femoral condyle
- femur
- tibia
when you lock out your knee, acl tightens, pcl tightens, joint capsule tightens, and forces medial femoral condyle into internal rotation and allows us to fully lock out our knee (quite stable)
- femur will internally rotate and tibia will externally rotate
- possible medial meniscal distortion
Describe Q-angle
The Q-angle is measured by extending a line through the center of the patella to the anterior superior iliac spine and another line from the tibial tubercle through the center of the patella.
What happens if the patellar tracks laterally (measured from Q angle) in its groove?
we can get wear and rubbing on the patella that causes pain (patellofemoral pain)
Define: genu valgum
knock kneed
- q-angle greater than 20 degrees
- knee valgus
Define: genu varum
bow legged
- q-angle less than 10 degrees
- knee varus
Define: genu recurvatum
- knee bends backwards.
- excessive extension occurs in the tibiofemoral joint
Define: genu antecurvatum
- hyper flexed knees
How would you assess the LCL? MCL?
- MCL: valgus stress test
- LCL: varus stress test
How can we test for intracapsular swelling?
- patellar compression; ballottement (see lec video?)
- swipe (sweep tests)
How can we assess the ACL? (3)
- anterior drawer test
- lachman’s
- pivot shift
How can we assess the PCL? (2)
- posterior sag
- posterior drawer
How can we assess the meniscus? (3)
- Apley’s compression
- Mcmurray’s
- joint line tenderness
Describe: knee sprains
- mechanisms (2)
- direct blow (valgus position or anterior)
- torsion or hyperextension (changing directions); sprains are worse if foot is fixed/planted
Describe 1st degree knee sprains; list treatments
- mild pain, mild swelling
- no snap or pop
- no limp, no effusion, no increased laxity
- treatment: POLICE, physiotherapy, brace
Describe 2nd degree knee sprains; list treatments
- pain, tenderness, snap
- swelling
- effusion if intraarticular
- limp
- treatment: POLICE, physiotherapy, brace, see M.D., longer period of recovery
Describe 3rd degree knee sprains
- complete rupture of ligaments
- more pain, tenderness, snap/pop
- marked swelling and effusion
- unstable or won’t bear weight
- marked increased laxity, soft endpoint
- treatment: NPO, stabilize + transport to hospital, will need brace +/ or surgery, follow with extensive physio, rehab
What are some hallmark signs on an x ray of a tendon & ligament injury
collagen fiber disruption and malalignment
