#5 Flashcards
7 Features of the proximal FEMUR BONE
1.Head; 2. Fovea Capitis; 3.Neck; 4.Greater Trochanter; 5.Lesser Trochanter; 6.Intertrochanteric line; 7.Intertrochanteric Crest.
The FEMUR is the…
longest and strongest bone in the body
Proximally, the FEMUR articulates with the…
acetabulum to form the hip joint.
As the FEMUR goes from proximal to distal, it courses…
medially. The medial coursing is generally more pronounced in women due to their wider pelvises.
The FOVEA CAPITIS is…
a small central pit on the femur’s head, from which a ligament runs to the acetabulum, helping to secure the femur.
The HEAD of the FEMUR attaches distally to..
the neck of the femur.
Which way does the NECK of the femur angle and why does it do so?
The neck of the femur angles laterally to join the shaft of the femur, because the femur articulates with the lateral aspect of the pelvis rather than the distal aspect.
The weakest part of the FEMUR is…
the neck, which is often the site of fracture when someone gets a “broken hip”.
The GREATER TROCHANTER is located…
at the juncture of the femur’s shaft and neck, proximal to the shaft on the lateral side.
The LESSER TROCHANTER is located…
At the juncture of the femur’s shaft and neck on the medial-posterior side, distal to the greater trochanter and head.
The GREATER TROCHANTER and LESSER TROCHANTER serve as…
sites of attachment for thigh and buttock muscles.
The INTERTROCHANTERIC LINE is located…
on the anterior femur, between the greater and lesser trochanters, which it connects.
The INTERTROCHANTERIC CREST is located…
on the posterior femur, between the greater and lesser trochanters, which it connects.
The GLUTEAL TUBEROSITY is located…
on the lateral side of the posterior shaft of the femur and just distal to the intertrochanteric crest.
The LINEA ASPERA is a …
long vertical ridge on the posterior shaft of the femur, which blends out of the more proximal gluteal tuberosity.
The MEDIAL and LATERAL SUPRACONDYLER LINES…
diverge in their respective directions from the LINEA ASPERA on the distal shaft of the femur.
The MEDIAL and LATERAL CONDYLES are…
wheel like protrusions on the distal end of the femur, which articulate with the tibia’s condyles to form the knee joint.
5 Features of middle FEMUR.
1 .Shaft; 2.Gluteal Tuberosity; ; 3.Linea Aspera; 4.Medial Supracondyler line; 5.Lateral Supracondylar line.
7 Features of distal FEMUR.
1.Medial Condyle; 2.Lateral Condyle; 3.Medial Epicondyle; 4.Lateral Epicondyle; 5.Adductor Tubercle; 6.Patellar Surface; 7.Intercondylar Notch.
The MEDIAL and LATERAL EPICONDYLES…
flank their respective condyles, proximally.
The ADDUCTOR TUBERCLE lies…
on the superior surface of the medial epicondyle.
The PATELLAR SURFACE is …
a smooth surface on the anterior aspect of the femur between the medial and lateral condyle, which articulates with the patella.
The INTERCONDYLAR NOTCH lies…
on the posterior aspect of the femur, between the medial and lateral condyles.
“PATELLA” means…
“small pan”.
The PATELLA is…
a triangular sesamoid bone enclosed in the quadriceps tendon.
The QUADRICEPS TENDON…
secures the anterior thigh muscles to the tibia.
The PATELLA’s functions to…
protect the knee anteriorly, reduce friction between the quadriceps tendon and the femoral condyles, and give leverage to the thigh muscles acting across the knee in extending the leg by acting as an “anatomical pulley”.
The KNEE JOINT COMPLEX consist in…
the tibiofemoral (aka knee) joint between the femur and the tibia and the patellofemoral joint between the patella and the femur. Both are contained in the knee’s joint capsule.
Is the proximal tibiofibular joint part of the knee joint complex? Why or why not?
No, since it isn’t contained in the capsule of the knee joint or functionally related to it.
The KNEE (aka TIBIOFEMORAL) JOINT is located…
between the medial and lateral condyles of the femur and the plateau on the proximal surface of the tibia.
The KNEE (aka TIBIOFEMORAL) JOINT is classified as..
a freely movable synovial modified biaxial hinge joint.
The movements of the leg/thigh at the KNEE (aka TIBIOFEMORAL) JOINT
- Flexion/extension of the leg (reverse action when leg is fixed, thigh) in the sagittal plane around a medial lateral axis. 2. Medial/lateral rotation of the leg (reverse action when leg is fixed, thigh) in the transverse plane around a vertical axis.
The COLLATERAL LIGAMENTS of the tibio-femoral (aka knee) joint are…
The medial collateral ligament (MCL) and the lateral collateral ligament (LCL).
The MEDIAL COLLATERAL LIGAMENT runs…
from the medial surface of the medial epicondyle of the femur to the medial surface of the proximal tibia (i.e., to the medial surface of the tibia’s medial condyle).
The MEDIAL COLLATERAL LIGAMENT functions to…
limit abduction at the tibiofemoral (aka knee)joint.
The LATERAL COLLATERAL LIGAMENT runs…
from the lateral surface of the lateral epicondyle of the femur to the lateral surface of the head of the fibula.
The LATERAL COLLATERALL LIGAMENT functions to…
…limit adduction at the tibiofemoral joint.
The CRUCIATE LIGAMENTS of the tibiofemoral (aka knee) joint are…
The ACL (anterior cruciate ligament) and PCL (posterior cruciate ligament).
The ANTERIOR CRUCIATE LIGAMENT (ACL) runs…
from the medial aspect of the lateral condyle of the femur to the anterior intercondylar region of the tibia.
The ANTERIOR CRUCIATE LIGAMENT (ACL) functions to limit…
1) anterior translation of leg relative to thigh (or posterior translation of thigh relative to leg), 2) hyperextension, and 3) medial/lateral rotation of leg (all at tibiofemoral joint).
The most commonly injured ligament of the knee joint is the…
anterior cruciate ligament (ACL)
The POSTERIOR CRUCIATE LIGAMENT (PCL) runs…
from the lateral aspect of the medal femoral condyle to the posterior intercondylar region of tibia.
The POSTERIOR CRUCIATE LIGAMENT functions to limit…
1) posterior translation of the leg relative to the thigh (or anterior translation of the thigh relative to the leg when leg is fixed) 2) extreme flexion.
The PATELLAR LIGAMENT is…
located between the patella and the tibial tuberosity and is really just an extension of the quadriceps tendon.
The MENISCI are…
fibrocartilaginous, crescent shaped located within the tibiofemoral joint on the tibia, which aid in cushion and shock absorbtion.
Are the MENISCI thicker at their center or periphery and why?
They are thicker at their periphery in order to transform the flat tibial plateau into two shallow sockets that receive the femoral condyles thus, increasing congruency and stability of the tibiofemoral joint.
The MEDIAL MENISCUS and MEDIAL COLLATERAL LIGAMENT are…
attached, so forces which stress the MCL may also be transferred to and damage the medial meniscus and, hence, they are often damaged together.
Do the MENISCUS heal why? Why or why not?
No, because they do not have a good blood supply.
Aside from menisci and ligaments, what other structures exist in the tibiofemoral joint?
BURSAE
If a MENISCUS is TORN, symptoms may include…
pain and irritation with each flexion or extension; the knee may lock up.
Some causes of a TORN MENISCUS are…
an excessive rotational force or severe abduction/adduction of knee joint or other excessive compressive force.
What is the SCREW-HOME mechanism of the tibiofemoral joint?
When the thigh is stable, during the last 30 degrees of tibiofemoral joint extension the leg laterally rotates at the tibiofemoral joint to help lock the joint and increase stability. If the leg is fixed, the thigh medially rotates during the last 30 degrees of extension.
What stops full extension of the tibiofemoral joint?
It is not stopped (like the elbow joint) by the locking of bones. Rather, tension of the soft tissue located on the posterior knee, i.e, the hamstring and gastrocnemius tendon.
The PATELLOFEMORAL JOINT is located…
within the capsule of the knee joint, between the posterior surface of the patella and the patellar surface of the femur (sometimes confusingly called “the “intercondylar groove”).
The PATELLOFEMORAL JOINT is classified as a…
freely movable, gliding, non-axial, synovial joint.
The movements allowed at the PATELLOFEMORAL joint are…
distal and proximal gliding along the femur. When the tibiofemoral joint is in full extension, the patella sits proximal to the femur’s patellar surface (intercondyler groove) and can be moved around; when the joint is flexed, the patella is located within the groove of the patellar surface and, hence, its mobility is greatly reduced.
A softening or wearing away of the articular cartilage on the deep surface of the patella is called…
CHONDROMALACIA PATELLA.
CHONDROMALACIA PATELLA is most often caused by…
a patellofemoral tracking disorder, that occurs when the patella shifts out of place as the leg flexes or extends, causing the patella to glide over a femoral condyle. In most cases, the patella shifts too far laterally, but in a few cases it shifts medially.
Some possible causes of improper patellofemoral tracking are…
1) tightness in the vastus lateralis or 2) tightness in the iliotibial band, or 3) relative weakness of the vastus medialis, or 4) direct trauma to the knee.
The FEMORAL ANGLE OF INCLINATION is…
the angulation of the head/neck relative to the shaft of the femur within the frontal plane.
What is the normal FEMORAL ANGLE OF INCLINATION and what can result from deviations from this angle?
125 degrees. Altered angles of inclination yield suboptimal alignment of the femoral head in the acetabulum, which can result in decreased shock absorption and increased degenerative changes over time.
A femoral angle of inclination markedly less than 125 degrees is called…
COXA VARA, which results in a higher lower extremity.
A femoral angle of inclination markedly greater than 125 degrees is called
COXA VALGA, which results in a lower lower extremity.
The FEMORAL TORSION ANGLE results from…
the medial rotation of the femoral shaft that occurs embryologically; the head and neck maintain their position, the shaft twists medially.
The FEMORAL TORSION ANGLE is measured by…
the FEMORAL ANTEVERSION ANGLE.
The FEMORAL ANTEVERSION ANGLE is
the deviation of the head and neck of the femur from the frontal plain.
What is the Normal FEMORAL ANTEVERSION ANGLE and what results from uncompensated deviations from this angle.
15 degrees. Uncompensated deviations will result in suboptimal alignment of the femoral head in the acetabulum, which can cause decreased shock absorption and increased degenerative changes over time.
A FEMORAL ANTEVERSION ANGLE markedly less than 15 degrees is called…
FEMORAL RETROVERSION.
Compensating for FEMORAL RETROVERSION results in…
lateral rotation of femur to line up the femoral head in the acetabulum, resulting in toe-out posture.
A FEMORAL ANTEVERSION ANGLE markedly greater than 15 degrees is called…
EXCESSIVE FEMORAL ANTEVERSION.
EXCESSIVE FEMORAL ANTEVERSION results in…
medial rotation of the femur to line up the femoral head in the acetabulum, resulting in toe-in posture.
Abduction of the tibia relative to the femur is called…
GENU VALGUM
Normal GENU VALGUM is…
5 to 10 degrees.
GENU VALGUM greater than 10 degrees is called…
EXCESSIVE GENU VALGUM (“knock-knees”).
EXCESSIVE GENU VALGUM results in…
excessive compression forces at the lateral tibiofemoral joint and excessive tensile forces at the medial tibiofemoral joint.
Adduction of the tibia relative to the femur is called…
GENU VARUM (“bow-leggedness”).
GENU VARUM results in…
excessive compressive forces at the medial tibiofemoral joint and excessive tensile forces at the lateral tibiofemoral joint.
The Q-ANGLE is …
the angle of pull of the quadriceps on the patella.
The Q-ANGLE is measured by…
the intersection of 2 lines; one from the tibial tuberosity through the center of the patella and one from the center of the patella to the ASIS.
What does ASIS stand for..
Anterior Superior Iliac Spine.
Normal Q-ANGLE is…
10 degrees for a man and 15 degrees for a woman (due to wider pelvis).
Excessive Q-ANGLE results in…
increased lateral pull of the distal quadriceps tendon on the patella, which pulls the patella laterally, causing it to ride against the lateral side of the patellar surface (intercondylar groove) and can lead to chondromalacia patella.
When excessive Q-ANGLE causes chondromalacia patella, one treatment approach is to…
,strengthen the vastus medialis muscle to help counter the lateral pull of the vastus lateralis.
Which causes excessive Q-ANGLE, GENU VARUM OR EXCESSIVE GENU VALGUM?
EXCESSIVE GENU VALGUM.
Extension (and hyperextension) of the tibiofemoral joint is measured by…
2 lines; one that runs through the center of the shaft of the femur and one that runs through the center of the shaft of the tibia.
How much hyperextension at the tibiofemeral joint is normal and why is it so?
Up to 10 degrees of knee hyperextension is normal because the tibial plateaus slant posteriorly and, when upright, or center of gravity is slightly forward of the knee joints; slight hyperextension also allows the quadriceps to relax during standing.
Hyperextension at the tibiofemoral joint beyond 10 degrees is called…
GENU RECURVATUM
Which facet of the posterior PATELLA is larger?
The lateral facet.
