Download Knee Power point

Question
What are some structures found in the
knee?
The Knee Unit
the knee joint is the largest joint space in
the body
it is greatest at 30 degrees of flexion
the knee is considered a synovial joint b/c
it is aligned with the joint capsule
the synovial layer secretes synovial fluid
(like oil to a car) to help lubricate the joint
and keep it moving
purpose of synovial fluid
– lubrication
– nutrient rich
BONES
Femur
largest bone in the body
distal end makes up knee
– forms convex medial and lateral condyles
– medial condyle is larger and longer in the AP
direction, which causes external tibial rotation
Tibia
2 tuberosities
– concave in nature
– separated by popliteal notch (Tibial Spine)
ACL & PCL attach to the tibial spine
ACL & PCL are named from their
attachment on the tibia
Tibia Fracture
Patella
Sesmoid bone
– largest one in the body
– lies within the quad tendon to increase
function
Function
– protect anterior knee
– increase mechanical advantage
patella is most palpable in extension b/c it
is above the trochlear groove
at 30 degrees of flexion, the patella is in
the trochlear groove
patella is held in place by the retinaculum
lateral retinaculum is stronger than medial
retinaculum
Why patella dislocation happens
laterally ?
weak VMO
shallow trochlear groove
small or abnormal patella
increased Q-angle
tight IT band
tight lateral retinaculum
Chondromalacia Patella
LIGAMENTS
ALL STATIC STABILIZERS
MCL - Medial Collateral
Ligament
Injured by valgus force
2 parts
– Deep
close to bones; thin layer
thickening of joint capsule, intracapsular
injury causes effusion (joint swelling)
attaches to the medial meniscus
– Superficial
forms the MCL
palpable
extracapsular
injury causes edema (swelling outside the joint)
LCL - Lateral Collateral
Ligament
thickening of capsule
does NOT attach to lateral meniscus
attaches to fibular head and attaches to
lateral epicondyle
very palpable
ACL - Anterior Cruciate
Ligament
attaches on tibia and lateral femoral
condyle (medial aspect)
moves superior, posterior, lateral
injury happens by anterior blow to femur or
deceleration with rotation
prevents the tibia from moving anteriorly
PCL - Posterior Cruciate
Ligament
attaches on tibia and medial femoral
condyle (lateral aspect)
moves superiorly, anteriorly, medially
injury happens by anterior blow to tibia or
posterior blow to femur
MENISCUS
curved, wedged, fibrocartilaginous discs
lies between the femoral condyles and
tibial plateaus
the outer edge is thicker than the inner
edge
the inner 2/3 of menisci are avascular (no
blood supply)
the outer 1/3 is called the "red zone"
because it is highly vascular (has blood
supply)
reasons for having the menisci
– enhance stability of knee
– assist with knee motion by decreasing friction
– shock absorber
Menisectomy - removal of the meniscus
the lateral and medial meniscus are connected
by the transverse ligament located in front of the
tibial spine
Medial meniscus - "C" shaped
Lateral meniscus - "O" shaped
Medial meniscus is larger than lateral meniscus
Medial meniscus is attached to entire periphery
(outer edge), and intrachonduloar eminence
(tibial spine), which is also the attachment for the
ACL
Lateral meniscus is loosely attached
Meniscal Tears
Bucket Handle
– occurs in the middle of the meniscus (red-white zone)
– often times posterior
– most common
Peripheral Tear
– red zone
– responds extremely well to surgery
Avascular Tear
– white zone
– must be removed and cleaned up on the edges
– heals poorly because no blood supply
Hamstring Group
Quadricep Group
Bony Land Marks
Palpations
Tibial Spine
Head of fibula
Palpations
Patella
Patella Superior Pole
Palpations
Tibial Tubercle
Gerdy’s Tubercle
Palpations
Patella Inferior pole
Gastrocnemius
Palpations
Patellar Tendon
Quadriceps
Vastus Medialis
Hamstrings
ROM
Flexion and Extension
Ab and Adduction
Dorsiflexion and plantarflexion
Special Tests
Valgus Stress Test (full extension)
Steps Patient is supine with the involved leg close to the edge of the table
and the knee in full extension Examiner supports the medial portion of the
distal tibia with one hand while the other hand grasps the knee along the
lateral joint line. Examiner applies a medial (valgus) force to the knee & the
distal tibia is moved laterally while the knee is in complete extension
Positive Test
Increased laxity, pain, and guarding
Positive Test Implications
Injury to the MCL, medial joint capsule; probable ACL/PCL involvement if there
is no endpoint
https://www.youtube.com/watch?v=6dQS0A9QQpc
Varus Stress Test
Steps: Patient is supine with the involved leg close to the edge of
the table and the knee is in full extension. Examiner supports the
lateral portion of the distal tibia with one hand while the other hand
grasps the knee along the medial joint line. Examiner applies a
lateral (varus) force to the knee & the distal tibia is moved medially
while the knee is in complete extension
Positive Test
Increased laxity, pain, and guarding
Positive Test Implications
Injury to the LCL, lateral joint capsule, & arcuate ligament; probable
PCL (& maybe ACL) involvement if there is no endpoint
https://www.youtube.com/watch?v=vFPsnWhjh6E
Lachman’s
Patient is supine with his/her knee passively flexed to approximately 20
degrees & hands crossed across his/her chest. Examiner's thumb of the
same–side hand as the knee to be examined is placed at the anterior
medial tibial plateau/joint line, while digits 2–5 are positioned posterior,
slighty distal to the popliteal fossa. Examiner's contralateral hand is placed
laterally around the distal femur, just proximal to the patella with the thumb
anterior & the digits 2–5 are positioned posteriorly. Examiner sets the tibia
by pushing posterior (to make sure the PCL is in tact). Examiner provides
an anterior force to the tibia while applying posterior pressure to the femur;
repeats the process 2–3 times
Positive Test
Increased anterior tibial translation, pain
Positive Test Implications
ACL tear (primary posterolateral bundle but also the anteromedial bundle)
https://www.youtube.com/watch?v=gfN-p-xZx24
Positive Laahman’s
https://www.youtube.com/watch?v=8maLL
ODKJwk
Anterior Drawer
StepsPatient is lying supine with his/her hip flexed 45 degrees & knee flexed 90
degrees
Examiner sits on the patient's foot & grasps the tibia just below the joint line
Examiner's thumbs are placed along the joint line on either side of the patellar tendon
& the index fingers are used to palpate the hamstring tendons
Examiner ensures that the patient is relaxed, esp. the hamstring tendons
Examiner draws the tibia straight forward (no rotation)
Positive Test
Increased anterior tibial translation, pain
Positive Test Implications
ACL tear (mainly the anteromedial bundle because the posterolateral bundle is basically
laxed in this position)
https://www.youtube.com/watch?v=yQdBrr3
Mmj0
Posterior Drawer
Steps Patient is lying supine with his/her hip flexed to 45 degrees & knee
flexed to 90 degrees
Examiner sits on the patient's foot & grasps the tibia just below the joint line
Examiner's thumbs are placed along the joint line on either side of the
patellar tendon
Examiner ensures that the patient is relaxed, esp. the quadriceps
Examiner pushes the tibia posteriorly
Positive Test
Increased posterior tibial translation, pain
Positive Test Implications
PCL tear
https://www.youtube.com/watch?v=KAUDTMu8fS0
McMurry’s Test
Steps Patient is supine
Examiner stands lateral & distal to the involved knee with one hand supporting the lower leg
Examiner positions thumb & index finger of the opposite hand in the anteromedial & anterolateral
joint lines on either side of the patellar tendon
Examiner keeps the tibia in the neutral position, applies a valgus stress through knee flexion &
varus stress through knee extension
Examiner internally rotates the tibia & applies a valgus stress through knee flexion & a varus
stress through knee extension
Examiner externally rotates the tibia & applies a valgus stress through knee flexion & a varus
stress through knee extension
Positive Test
Popping, clicking, or locking of the knee; pain from within the joint
Positive Test Implications
Possible meniscus tear
https://www.youtube.com/watch?v=fkt1TOn1UfI
Apley’s Compression
Steps - Patient is prone with his/her knee flexed to 90
degrees
Examiner applies pressure to the plantar aspect of the
heel, applying an axial load to the tibia while
simultaneously internally & externally rotating the tibia
Positive Test
Pain; possible clicking
Positive Test Implications
Possible meniscus tear
https://www.youtube.com/watch?v=At0FdkHaCGo
Ober’s test
Steps - Patient is lying on the side opposite that being tested
Examiner stabilizes the pelvis with one hand and the lateral side of the
examiner's hip against the patient's pelvis
Examiner grasps the femur above the knee with the other hand & abducts &
extends the hip
Examiner allows the hip to passively adduct to the table with the knee
straight
Positive Test
Leg does not adduct past parallel
Positive Test Implications
IT Band tightness
https://www.youtube.com/watch?v=zNH-2reV5uE