Masterclass 3 - Knee Flashcards
Why is the knee susceptible to injury
Two long lever arms (tib, and femur)
Relies on ligaments and muscles for strength and stability rather than bony configuration
What is the function of the patella within the knee joint?
Improves the efficiency of knee extension
Acts as a guide for the quadriceps tendon
Decreases friction
Controls capsular tension
Serves as a bony shield for the femoral condyles
How does the patella load vary with different activities?
0.3x BW while walking
2.5x BW during stair climbing
3.5x BW descending stairs
7x BW during squatting.
What type of joint is the tibiofemoral joint
Modified hinge joint
How many DOF does the tibiofemoral joint have
- Flex/ext, rotation
Patellofemoral syndrome pain location
Anterior knee
Where is the anatomically patella safest
When it is sitting inside the trochlear groove
How many degrees of flexion is the patella considered to be safe
70-130 deg of flexion (130 deg = knee bent)
This is because it is sitting inside the trochlear groove
What are the three most common non-traumatic knee injuries (based on prevalence)
Knee OA
Prepatellar Bursitis
ITB Syndrome (runners knee)
What are the variables that may be related to a poorer prognosis in patients with knee osteoarthritis
Female
Age
Knee varus
Other joints with arthritis
High BMI
Patellofemoral syndrome aggravating activities
Stairs, squatting, sitting
Patellofemoral syndrome physical exam findings
Tenderness around kneecap
Patella maltracking
What sort of results are expected in an x-ray from someone with patellofemoral syndrome
Results often come back as normal
What are the two main differences between Patellofemoral syndrome and Chondromalacia Patellae
PFPS will be tender around the kneecap vs CP will be tender under the kneecap. CP X-ray will also reveal cartilage damage around the patella
Will an increased Q angle lead to genu valgum or genu varus
Genu valgum
Will a decreased Q angle lead to genu valgum or genu varus
Genu varus
Does knee valgum or knee varus occur more in those with knee pain
knee valgus
Knee varum is more likely to develop what chronic injury
Medial OA
Knee normal ROM flexion
135 deg
Knee normal ROM extension
0 to -5 (hyperextension)
Knee functional tests
Squat
Jump
Walking
Single leg stance
Sit-stand
Hop (DL/SL)
Step down
When performing functional knee tests, what would be preferred test, step up or step down
Step down because it can load the knee more (7x BW)
What are the three types of bursitis at the knee
Infrapatellar
Prepatellar
Suprapateller
Where is pain most present in fat pad impingement pt
Medial and lateral to the patella tendon
What movements cause the most pain in fat pad impingement
Extension
What muscles are most commonly weaker in fat pad impingement pt? How does this contribute to the injury
Weak hamstrings because they’re not bringing their knees into flexion, creating repeated hyperextension
