Lower Limb joints Flashcards
Wilson
What is the mechanical axis of the femur?
87 degrees
What is the anatomical axis of the femur?
84 degrees
The hip joint centre is located where?
Middle of the head of othe femur
What is the anatomical and mechanical axis of the tibia?
93 degrees
A medial deviation from the axis of the bone is known as the?
Vara (varus)
A lateral deviation from the axis of the bone?
Valga (Valgus)
What is the normal angle of inclination of the femur?
120 degrees
(range is 120-135 degrees
thus creating Ward’s triangle
What is a coxa valga?
when the Ward’s trinagle angle of the femur increases to more than 135 degrees
(this is an excessive slant)
What is a coxa vara?
When the Ward’s triangle angle degreases to less than 120 degrees.
congenital = 90 degrees
aquired = less than 90 degrees
This joint is a synovial joint of the ball and socket variety. It is formed between the head of the femur and the acetabulum of the innominate bone (pelvic girdle).
Hip joint
(more stable than the glenohumoral joint)
What is a ball and socket joint?
A oint that can move in all 3 planes
Coronal
Sagital
Axial
Which three bones fuse to form the acetabular fossa
ilium, ischium, pubis
Innominate
(Pelvic girdle)
Areas of thick fibers that go in one direction are known as?
Ligaments
The hip joint is surrounded by what? and what is that thing lined with?
It is surrounded by an articular capsule that is lined with a synovial membrane. And the articular surfaces are covered with hyaline cartilage.
Thickning of the articular capsule forms what?
Intrinsic ligaments
What are the intrinsic ligaments of the hip joint?
Anteriorly
Iliofemoral ligament
pubofemoral ligament
Posteriorly
Ischiofemoral ligament
Which ligament of the hip joint is the strongest and most important because it supports the hip joint in erect posture?
Iliofemoral ligament
The articular capsule of the hip joint is composed of what type of fibers?
parallel fibers
What happens to the fibers in the articular capsule during flexion and extension?
The fibers unwind during flexion
Extension causes the fibers to spiral (become oblique) = draws acetabulum and femur closer together like a screw. = hip stability
When do you have the maximal contact between the head of the femur and the iliofemoral ligament.
during extension
Allows you to stand with mild muscle activity
What is the infamous ligament of the hip that has an artery running through it?
Ligament of the head of the femur with Acetabular artery
(presence of the artery is variable and may not be patent)
This ligament runs in the acetabular fossa
Add image for slide 16
CT scan Though Hip
A. Acetabular fossa
B. Obturator internus
C. Head of femur
D. Gluteus maximus
What occurs when yo fracture the neck of the femur and why?
Shotening and lateral rotation of the affected limb
Hip injuries cause its myotatic unit to spasm which provides protective splinting. Stonger muscle (lateral rotators) will over power weaker muscle (medial rotators)
What are the medial rotators of the hip?
Gluteus medius (anterior fibers)
Gluteus minimus
Tensor of fascia lata
(towards anterior superior iliac spine)