S3_L2: Kinesiology of the Knee Complex Flashcards
A non-synovial, false joint, that is the articulation between the posterior patella and femur
Patellofemoral joint
The largest sesamoid bone in the body
patella
It acts as an anatomical pulley for quadriceps tendon thereby increasing the moment arm, thus increasing the torque generating capacity of the muscle. It also lengthens the lever arm of the knee joint, thus increasing the ROM of knee joint.
Patella
divides patella into Medial and Lateral Facets
Vertical ridge
Medial and Odd Facets are divided by this ridge
2nd vertical ridge (More medial)
The normal ratio of the length of patellar tendon to the length of patella
1:1
Used to determine patellar height
Insall-Salvati Index
Characterized by Insall-Salvati Index is >1:1 (>1.2), patella is placed upwards, thus increases length of patellar tendon
Patella alta
Characterized by Insall-Salvati Index is <1:1 (<0.8), patella is placed downwards, thus decreases length of patellar tendon
Patella baja
TRUE OR FALSE: Both patella alta and patella baja affect the effectiveness of anatomic pulley mechanism
True
In Patellofemoral Pain Syndrome/Stress (PFPS), there is pain during weight-bearing (1)___ and during non-weight-bearing (2)___.
- deep flexion
- terminal knee extension
When the knee is extended, only the ____ of patella is in contact with femur.
Inferior pole
TRUE OR FALSE: If the patella is fixed, knee extension and flexion ROM will be increased
False. It will be decreased
Enumerate the patellar motions for the x, y, and z axes
X-axis: flexion and extension
Y-axis: medial and lateral tilting
Z-axis: medial and lateral rotation
What is the knee flexion ROM for normal gait?
Normal gait = 60-70 degrees of knee flexion
Screw-home mechanism is also known as?
Terminal Knee Rotation / Locking Mechanism of the Knee
TRUE OR FALSE: To externally rotate the tibia to lock the knee, there is no muscle acting
True
What muscle medially rotates the tibia to unlock the knee?
Popliteus
Close-packed position of knee
Full knee extension (with tibial ER)
For bony congruence and ligamental tautness
Open-packed position of knee
25°-30° of knee flexion
Arthrokinematics during OKC knee extension
tibia will roll and glide anteriorly
Arthrokinematics during OKC knee flexion
tibia will roll and glide posteriorly
Arthrokinematics during CKC knee extension
femur will roll anteriorly and glide posteriorly
Arthrokinematics during CKC knee flexion
femur will roll posteriorly and glide anteriorly
Enumerate the names of the anterior and posterior fibers of the meniscofemoral ligament
Anterior fibers: ligament of Humphry
Posterior fibers: ligament of Wrisberg
The oblique popliteal ligament is an expansion of what muscle?
Semimembranosus muscle
Acts to control valgus forces and secondary restraint to excessive anterior tibial translation
Medial Collateral Ligament / Tibial Collateral Ligament
Acts to control varus forces and secondary restraint to tibial external rotation
Lateral Collateral Ligament / Fibular Collateral Ligament
Which knee ligament merges with the tendon of biceps femoris to form a conjoint tendon collectively?
Lateral Collateral Ligament / Fibular Collateral Ligament
Condition where the infrapatellar bursae are inflamed
Clergyman’s knee
Condition where the prepatellar bursa is inflamed
Popeye’s Knee / Housemaid’s Knee
Fatty soft tissues found in knee joint that serve as shock absorbers when too much pressure is present (e.g. when kneeling). They also reduce frictional forces between structures.
Fat pads
Represents the vector of the combined pull of quadriceps femoris muscle and the patellar tendon
Quadriceps angle / Q-angle
Normal value range of Q-angle
10-15°
Additional: On average, males present with 14°, while females present with 17°
Enumerate the intersection lines of the Q-angle
- A line from ASIS to the midpoint of patella
- A line from tibial tubercle / tuberosity to the midpoint of patella
TRUE OR FALSE: The superior tibiofibular joint is not considered part of the knee complex. It is not contained within the knee joint capsule and functionally related to the ankle joint.
True
A synovial, double condyloid or modified hinge joint that is the articulation between the convex distal femur and concave proximal tibia.
Tibiofemoral joint
One of the most often injured joints in body and is considered to be the “puppet” of hip and ankle
Knee
Enumerate the 4 possible causes of genu recurvatum
- Weak muscles (quadriceps)
- Tight soleus
- Unstable knee joint
- Lax ligaments
Abnormally high knee adduction moments are associated with the development of ___.
medial knee osteoarthritis
TRUE OR FALSE: The patellar plicae are most commonly found below the patella / infrapatellar.
True
TRUE OR FALSE: The semiflexed position of the knee is the position of comfort in injuries.
True
TRUE OR FALSE: The synovial membrane of the knee joint capsule secretes and absorbs synovial fluid.
True
TRUE OR FALSE: During the embryonic stage, the knee space is separated into lateral and medial compartments by a septum. At 12 weeks, the synovial septum should be partially resorbed and retains posterior invagination (remnants) of synovium. These remnants have persistent folds which are referred to as the patellar plicae.
True
TRUE OR FALSE: The presence of the menisci reduces the chance for injuries and wear and tear as it distributes the pressure in the knee when WB.
True
TRUE OR FALSE: In adults, only the peripheral vascularized region of the meniscus is capable of inflammation, repair, and remodeling after a tearing injury. The avascular nature of the central (inner) portion of the meniscus reduces the potential for healing after an injury.
True
TRUE OR FALSE: Too much deep squatting / knee flexion causes excessive compression to the patella which may possibly lead to the Patellofemoral Joint Syndrome / Patellofemoral Joint Stress.
True
TRUE OR FALSE: In full knee extension, there is a potential frontal plane instability of the patellofemoral joint that is due to the physiological valgus of the knee.
True
TRUE OR FALSE: Fat pads are sensitive structures rich in nerve innervation.
True
TRUE OR FALSE: Lateral patellar instability is more common than medial patellar instability.
True
TRUE OR FALSE: The meniscofemoral ligament is not a true ligament because it is attached from the lateral meniscus going to the PCL to the medial femoral condyle.
True, because it doesn’t attach from bone to bone.
TRUE OR FALSE: If the patella is immobile or not moving optimally, its anatomical pulley function is decreased. Pain syndromes such as the Patellofemoral Pain Syndrome can occur as a result of the pull of quadriceps on the patella compressing the underlying structures (bursae, patellar tendon).
True
TRUE OR FALSE: A factor contributing to the screw-home mechanism is the medial pull of the quadriceps femoris (obliquity of Q angle from quadriceps femoris); thus, it extends the knee but also tries to rotate the tibia externally.
False, it’s the lateral pull
TRUE OR FALSE: The ACL is taut in full extension, especially hyperextension. Its tension pulls the tibia such that it generates a rotation motion during the screw-home mechanism.
True
TRUE OR FALSE: The medial meniscus is an intrasynovial and intracapsular structure.
True
The automatic rotation of the knee to lock it during terminal knee extension (the last 20-30 degrees of extension)
Screw-home mechanism
Determine the corresponding descriptions of the fat pads
- Posterior to Quadriceps tendon
- Deep to the patellar tendon
- Anterior to Quadriceps tendon
A. Anterior Suprapatellar Fat Pad
B. Posterior Suprapatellar Fat Pad
C. Infrapatellar (Hoffa’s) Fat Pad
- B
- C
- A
Determine the corresponding motion occurring during CKC knee motions
- IR of femur
- Femur glides anteriorly on tibia
- ER of femur
- Femur glides posteriorly on tibia
A. CKC Knee Flexion
B. CKC Knee Extension
- B
- A
- A
- B
Determine the corresponding motion occurring during OKC knee motions
- ER of tibia
- Tibia glides posteriorly on femur
- Tibia glides anteriorly on femur
- IR of tibia
A. OKC Knee Flexion
B. OKC Knee Extension
- B
- A
- B
- A
Determine the corresponding patellar contact in these varying degrees of knee flexion
- Middle portion of patella
- More contact on odd and lateral facets
- Superior facet
- Inferior facet generates compressive contact
A. 20° of knee flexion
B. 45° of knee flexion
C. 90° of knee flexion
D. Greater than 90° of knee flexion
- B
- D
- C
- A
Determine the corresponding descriptions of the Frontal Plane Malalignment of the tibiofemoral joint
- LCL is often stretched, overworked
- WB line shifts laterally, thus lateral structures are compressed, weak, and underworked
- Contributes to the progression of medial compartment knee osteoarthritis and corresponding medial joint laxity
- MCL is often stretched, overworked
- WB line shifts medially, thus medial structures are compressed, weak, and underworked
- Pull of muscles on lateral side of hip would predispose patella to be subluxed laterally
A. Genu valgum / Knock knees
B. Genu varum / Bow legs
- B
- A
- B
- A
- B
- A
Determine the corresponding connections of the menisci
- Semimembranosus tendon
- ACL (anterior horn)
- MCL
- ACL (common tibial attachment)
- PCL (posterior horn)
- Popliteus
- LCL
A. Medial meniscus
B. Lateral meniscus
- A
- A
- A
- B
- A
- B
- B
Determine the corresponding descriptions of the ligaments of the posterior capsule of the tibiofemoral joint
- Reinforce posteromedial aspect of knee
- Reinforces posterolateral capsule obliquely on a medial-to-lateral diagonal from proximal to distal
- From central part of posterior capsule to Posterior medial tibial condyle
- From near proximal origin of MCL and Adductor Tubercle to Posteromedial tibia, capsule and posteromedial aspect of medial meniscus
- Inserts into oblique popliteal ligament on medial side of joint
- From tendon of popliteus muscle and posterior capsule to posterior aspect of fibular head
A. Oblique Popliteal Ligament
B. Posterior Oblique Ligament
C. Arcuate Ligament - Lateral Branch
D. Arcuate Ligament - Medial Branch
E. C and D
- B
- E
- A
- B
- D
- C
Determine the corresponding direction the synovial fluid is going in the ff knee motions / positions
- In the Semiflexed Position (OPP)
- During Knee flexion
- During Knee extension
A. Fluid moves anteriorly / forward
B. Fluid moves posteriorly / backward
C. Fluid is evenly distributed
- C
- B
- A
Determine the corresponding rotary stability provided by the ff structures
- Iliotibial band
- Semimembranosus
- Posterior cruciate ligament
- Biceps femoris
- Arcuate complex/Popliteus
A. Posteromedial Stability
B. Posterolateral Stability
C. Anteromedial Stability
D. Anterolateral Stability
E. Both A and C
F. Both B and D
G. Both A and B
H. Both C and D
- D
- A
- G
- B
- F
Determine the corresponding rotary stability provided by the ff structures
- Lateral collateral ligament
- Posterior oblique ligament
- Medial collateral ligament
- Posterolateral capsule
- Posteromedial capsule
A. Posteromedial Stability
B. Posterolateral Stability
C. Anteromedial Stability
D. Anterolateral Stability
E. Both A and C
F. Both B and D
G. Both A and B
H. Both C and D
- F
- E
- E
- F
- E
Determine the corresponding descriptions of the cruciate ligaments
- Smaller CSA, more obliquely oriented, longer, weaker
- Secondarily resists varus forces and prevent too much IR of tibia
- Oriented Superior, Lateral, Posterior
- Prevents hyperextension of knee
- Oriented Superior, Anterior, Medial
- If tibia is fixed, it will prevent excessive anterior translation of femur
A. Anterior Cruciate Ligament (ACL)
B. Posterior Cruciate Ligament (PCL)
- A
- B
- A
- A
- B
- B
TRUE OR FALSE: The menisci increase the concavity of the tibial plateau surfaces which contributes to the congruence of the tibiofemoral joint.
True
Note: If the femoral condyles sat directly on the relatively flat tibial plateaus, there would be a small contact area between the bony surfaces.
TRUE OR FALSE: The tibiofemoral joint is a double condyloid or modified hinge joint, where it is formed by 2 condyles articulating with 2 tibial plateaus.
True
TRUE OR FALSE: The shaft of femur is somewhat obliquely oriented while shaft of tibia is vertically oriented in its anatomical axis.
True
TRUE OR FALSE: The higher the Physiological Valgus Angle, the more obliquely deviated the tibiofemoral alignment is.
True
TRUE OR FALSE: The two femoral condyles are joined anteriorly by an asymmetrical, shallow groove called the femoral sulcus / patellar groove / patellar surface that engages the patella during early flexion.
True
TRUE OR FALSE: The cruciate ligaments are intracapsular and extrasynovial structures.
True
TRUE OR FALSE: Both medial and lateral menisci are open toward the intercondylar tubercles.
True
TRUE OR FALSE: The process of fluid diffusion to support nutrition of the menisci requires intermittent loading by either weight-bearing or muscular contractions. Subsequently, during prolonged periods of immobilization or conditions of non-weightbearing, the meniscus may not receive appropriate nutrition.
True
TRUE OR FALSE: The horns of the menisci and the periphery of the menisci are well innervated with free nerve endings (nociceptors) and three different mechanoreceptors (Ruffini corpuscles, pacinian corpuscles, and Golgi tendon organs).
True
TRUE OR FALSE: Posteriorly, the menisci are connected to each other by the transverse ligament.
False, this connection is found anteriorly
TRUE OR FALSE: At the periphery, the menisci are connected to the tibial condyle by the coronary ligaments, which are composed of fibers from the knee joint capsule. The menisci are unstable without the coronary ligaments.
True
TRUE OR FALSE: If the tibia is fixed, the ACL will act to prevent excessive posterior rotation of femur on tibia.
True
TRUE OR FALSE: The anteromedial bundle (AMB) of the ACL is taut at maximal knee flexion or beyond 90 degrees.
True
TRUE OR FALSE: The ACL is relatively lax at midrange and the entire ligament is taut in knee hyperextension.
True
TRUE OR FALSE: The ACL has 2 points of tautness, (1) Fully flexed and (2) Hyperextended.
True
TRUE OR FALSE: If treating a meniscal tear, it is better to do shallow squats because deep squats will add so much compression to the meniscus.
True
TRUE OR FALSE: If the ACL is torn, it is better to do deeper squats because when doing shallow squats, the femoral condyles are rolling and gliding much.
True
Note: Shallow squats are allowed if ACL tear is only minimal/small
TRUE OR FALSE: The C-shaped medial meniscus is larger and less mobile because of more ligament attachments, capsular restraints, and tendinous stabilization than the lateral meniscus. Additionally, its reduced mobility puts it at a greater risk for injuries.
True
TRUE OR FALSE: The Medial Collateral Ligament is a secondary restraint to excessive anterior tibial translation.
True
TRUE OR FALSE: The Lateral Collateral Ligament is a secondary restraint to tibial external rotation.
True
TRUE OR FALSE: The anterior and posterior horns of the medial meniscus are attached to the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), respectively.
True
TRUE OR FALSE: The anterior horn of the lateral meniscus and the anterior cruciate ligament share a tibial insertion site.
True
TRUE OR FALSE: The medial femoral condyle lies more directly in line with the shaft of femur.
False, it’s the lateral condyle
Additional: The lateral condyle is shifted anteriorly, while the medial condyle is shifted a bit posteriorly.