Joints of the Lower Limb Flashcards
The hip joint evolved to provide maximum ______ at the expense of ______.
maximum stability at the expense of mobility
The head of the femur fits within the ________ of the os coxae (hip bone).
acetabulum
What is the cartilaginous thing that deepens the acetabulum called?
The acetabular labrum
from latin “labrum” for lip
What structure is responsible for attaching the head of the femur to the pelvis? (hint: it is found inside the acetabulum)
The ligamentum teres
What is the intertrochanteric line? What is the intertrochanteric crest?
The line is a bony ridge running from the greater to the lesser trochanter on the ANTERIOR side.
The crest is the same thing, but on the POSTERIOR side.
Name the four muscles that attach to the greater trochanter.
- Gluteus minimus
- Gluteus medius
- Piriformis
- Obturator internus (on the medial aspect of the greater trochanter)
What muscle attaches to the lesser trochanter?
The iliopsoas muscle
What structure spans the acetabular notch?
The transverse acetabular ligament.
Which structures do the iliofemoral ligament (aka Y ligament of Bigelow) span and what is its function?
Runs from the AIIS to the intertrochanteric line (anterior femur) and prevents hyperextension of the thigh by winding up during extension.
Which structures do the pubofemoral ligament span and what is its function?
Runs from the pubis to the anterior femur, prevents overabduction
Which structures do the ischiofemoral ligament span and what is its function?
Runs from the ischium to the greater trochanter, prevents posterior displacement of the femoral head.
Which artery is the major supply for the proximal femur?
Medial femoral circumflex artery (lateral femoral circumflex also supplies, but not “major”)
Medial femoral circumflex artery passes posteriorly around the neck of the femur while the lateral femoral circumflex artery passes anteriorly. They both branch from the deep femoral artery.
What is one major complication of an intracapsular fracture of the femoral head?
Damage to the medial femoral circumflex can cause avascular necrosis of the femoral head.
Define coxa vara and coxa valga.
Coxa vara is when the angle between the femoral neck and shaft is less than 125 degrees.
Coxa valga is when the angle between the femoral neck and shaft exceeds 140 degrees.
G=Greater than 140 degrees
Describe the nerve supply to the hip joint.
Anterior: Femoral nerve branches.
Posterior: The nerve to the quadratus femoris muscle (that is what it’s called), and a branch of the superior gluteal nerve.
Where may hip pain be referred to? What nerves?
Groin, anterior thigh and knee through femoral nerve branches - also supplies sensation to the L2 - L4 dematomes.
To the medial knee through branches of the obturator nerve, which passes through both joints.
What is Hilton’s law?
Any nerve which crosses a joint supplies sensation to that joint.
What is congenital dislocation of the hip?
Aka hip dysplasia. Movement of the head of the femur out of the acetabulum, usually posteriorly. Due to faulty development of the upper lip of the acetabulum.
Results in shortening, adduction and medial rotation of affected limb.
If an elderly patient sustained a fall and one leg is shortened and laterally rotated, what is the diagnosis?
Hip fracture
The patella ______ the angle of pull of the quads on the tibia and improves the ratio of motive:resistive torque by ____%
increases angle, improvement 50%
The radius of curvature is _______ across the lateral condyle, and as a result the condyles execute both rolling and _______ motions.
variable radius
rolling and sliding motions
As the knee is flexed, the tibia ________ rotates with respect to the femur.
internally/medially
As the knee is extended, the tibia _______ rotates with respect to the femur.
externally
What arteries supply blood to the knee joint?
Popliteal artery
Genicular arteries: Superior lateral, superior medial, middle, inferior lateral, inferior medial
Which artery supplies the ACL and PCL?
Middle genicular artery
Which nerves provide sensation from the knee joint?
Anteriorly - saphenous nerve (from the femoral nerve)
Posteriorly - tibial nerve and common peroneal nerve
Name the four bursae in the knee from superior to posterior.
Suprapatellar bursa
Subcutaneous prepatellar bursa
Subcutaneous infrapatellar bursa
Deep infrapatellar bursa
Compare and contrast the medial and lateral menisci.
Medial is C-shaped and larger, less mobile. Has a larger posterior horn.
Lateral is circular, smaller, more mobile.
What are the functions of the menisci?
Increase stability by deepening the tibial plateaus, decrease friction by 20%, increase contact area by 70%, absorb shock.
What do the meniscofemoral ligaments connect?
Posterior horn of the lateral meniscus to the intercondylar wall of the medial femoral condyle
Which collateral ligament is attached to a menisci?
The medial collateral ligament is attached to the medial meniscus
The ________ collateral ligament is broad, while the _______ collateral ligament is thinner and more cord-like.
medial is broad, lateral is cord-like
What is Q-angle? What is a normal Q-angle for males and females?
Angle formed by a line from the ASIS to the middle of the patella and a vertical line from the middle of the patella to the tibial tuberosity.
Males: 10 to 14 degrees
Females: 15-17 degrees
What is genu varum and valgum?
Genu varum - bow legged
Genu valgum - knock knees
True or false: Cruciate ligaments are named for their tibial attachments.
true
How does the leg need to twist to injure the ACL?
Lower leg must be internally/medially rotated with respect to the femur
What physical exam tests are used for ACL pathology?
Anterior drawer, Lachmann
How is the PCL often injured?
A direct blow to the anterior knee when the knee is bent
Which tendon lies between the lateral collateral ligament and the lateral menisci?
Popliteus tendon
What attaches to Gerdy’s tubercle?
The IT tract
How does pronation of the foot during walking/running cause IT band syndrome?
It causes excessive internal rotation of the tibia, so the IT band rubs around more on the lateral femoral condyle.
What is an “unhappy triad?”
- Torn ACL
- Torn MCL
- Torn medial meniscus
What is the name of the artery that supplies the head of the femur during development but isn’t that important as an adult?
The acetabular branch of the obturator artery.
What is the classic clinical presentation of hip fracture in an elderly patient?
Patient sustained a low-energy fall, now has pain, and is unable to bear weight.
On examination, the affected extremity is often shortened and externally rotated.
Define pre-patellar bursitis (housemaid’s knee).
Inflammation or swelling of the pre-patellar bursa.
What is a popliteal (Baker’s) cyst?
A swelling behind the knee, resulting from synovial fluid that escapes posteriorly through the joint capsule. It impairs flexion and extension of the knee joint.
What is genu valgum?
Knock-knee: a deformity in which the tibia is bent or twisted laterally. May occur as a result of collapse of the lateral compartment of the knee and rupture of the MCL.
What is genu varum?
Bowleg: a deformity in which the tibia is bent medially. May occur as a result of collapse of the medial compartment of the knee and rupture of the LCL.
Who is at risk for osteoarthritis of the knee?
Joggers and obese people
