patellofemoral joint Flashcards
week 10
patella anatomy
sesamoid bone
flat, triangluar, embedded in quad tendon
medial & lateral patellar retinaculum
fuctions as pulley and reduces friction
talk about patellar anatomy in full flexion, full extension and 45-60° of flexion
full flexion: femoral condyles help maintain MA of a lengthened quadriceps (passive insufficiency)
full extension: increases MA of a shortened quadriceps (active insufficiency)
45-60° of knee flexion: maximal MA and optimal length - tension relationship (highest torque)
patellar tendon length ? patella length
patellar tendon length = patella length (1:1)
patella baja (short tendon) =
more stable
patella alta (long tendon)
= less stable
patella site in central groove between femoral condyle facets:
- incongruent small patella and large femur
- lateral femoral facet is bigger
lateral femoral condyle sits slightly anterior and is more of a ___ _____ for the patella
bony block
patellar flexion:
during tibial-on-femoral flexion, patella:
- glides inferiorly
- enters intercondylar fossa
- rotates on the sagittal plane (apex of the patella moves posteriorly) “patellar flexion”
patellar facets
- articular cartilage (takes a lot of load and movement)
- slightly convex
- patellar ridge
How does the patella fit into the trochlea at different degrees of movement?
0° - no contact
20° - starts to move into grove
60°- majority in contact
90° - full contact with trochlea
what is incontact at the knee in full tibiofemoral extension
only the inferior pole is in contact with the femur
past 90 degrees of flexion what makes contact ?
at the patellafemoral joint
oddfacet makes contact
patellofemoral joint
what makes contact in full flexion?
only the lateral and odd facets are making contact with the femur
motion of patella occurs to keep?
keep the patella seated between the femoral condyles
patellar tilt occurs along what axis?
longitudinal
goes with frontal plane
what is the patellar tilt referenced by?
anterior surface of the patella
lateral patella tilt =
lateral edge of the patella approximates the surface of the lateral femoral range of motion
what are some symptoms of patella alta?
- congenital
- problems with patella ages 10-20
- patellofemoral pain
- high dislocations
what are some signs of patella alta?
- look at position of patella with knee in ex
- m/l glides
- j tracking sign
- patella tendon rupture
patellar shift
translations on the frontal plane
lateral patellar shift
= patella mvoing toward the lateral femoral condyle
the patella rotates about what axis?
rotations about an anteroposterior axis
what is patellar rotation referenced by?
apex of the patella
patella
medial rotation?
= patella spins around the anterioposterior axi with the apex pointing towrad the medial femoral
what dictatesthe medial and lateral rotation of patella?
patellar tendon(ligament)
Quadriceps Angle
the angle between:
- a line connecting ASIS to the midpoint of patella
- extension of a line connecting the tibial tubercle and midpoint of patella
- 10°-15° while knee in extension is considered normal (males lower, females higher)
the larger the Q-angle, the greater the?
lateral muscle pull on the patella
the line between the ASIS and the patella does not necessarily reflect the actual _______ _______ on patella
lateral pull
what joint(s) can knee osteoarthritis impact?
tibiofemoral joint
patellofemoral joint
or both
what type of OA is most researched?
tibiofemoral - more consistent disease progression compared to patellar OA.
symptoms of knee osteoarthritis?
- knee pain that is gradual in onset and worsens with activity
- knee stiffness and swelling
- pain after prolonged sitting or resting (more space = more swelliing)
- crepitus or a cracking sound with joint movement
- bakers cyst
risk factors for knee OA?
- history of intra-articular knee injury (post traumatic knee OA)
- reduced quadriceps muscle strength (get quad strength back)
- female sex
- age
- family history
- obesity
clinical classification criteria for knee osteoarthritis?
- knee pain
- joint stiffness ≤ 30 minutes
- crepitus
- bony enlargement (spurs)
- bony tenderness (at joint line too)
- no palpable warmth
- bakers cyst
what is a classic progression of knee stiffness with osteoarthritis?
morning stiff –> ≤ 30 minutes less stiff —> few hrs depending on activity —> gets worse
what is a major risk factor for knee osteoarthritis?
extensor weakness = symptomatic and radiographic knee OA
how many develop symptomatic radiographic knee OA due to obesity?
2 in 3
how many weeks of supervised Pt for a patient with knee and hip OA saw improved function and pain?
8 weeks
what is the primary management of knee OA?
focuses on taking proactive measures to prevent diseases from ever occuring
what is secondary management of knee OA?
emphasize the significane of identifying diseases in their early stages before symptoms manifest
what is tertiary management of knee OA?
preventing further damage and enhanging quality of life for those living with chronic conditions while minimizing impact of disease.
what are the 10 things on the prevention list for post traumatic osteoarthritis risk profile
- intra artiucalr injury/reinjury
- early return to sport
- obesity adiposity
- physical inactivity/sedentary behavior
- muscle weakness altered neuromuscular control
- fear of movement
- poor diet
- inaccurate beliefs/unrealistc expectatiosn
- insufficient and ill timed exercise therapy
- joint dysplasia
at what degree does the odd facet make contact with ridge?
135°
what is dynamic knee valgus
3 plans of movement (simultaneously)
contralateral pelvic drop ipsilateral trunk lean
dynamic valgus can be a combination of?
hip adduction
hip rotation
knee abduction
tibial rotation
ankle pronation
knee valgus cab result in increased what?
knee abduction loads
high abduction load increases risk of?
risk of ACL tear
Dynanic valgus is often observed in?
- ACL injury situations
- dynamic valgus is often observed in ACL injury situations
dynamic valgus and ground reaction forces?
dynamic valgus changes how ground reaction forces are absorbed
can functional tests for dynamic valgus predict who will be injured?
NO
was there an association between single elg drop jump and single leg squat screening for ACL injury risk (frontal plane only)?
NO
