Hip Flashcards
Hip is union of what 3 bones?
- ilium
- pubis
- ischium
Pelvis is referred to as?
osteoligamentous ring,
What 3 functions is the pelvis associated with?
- common attachment point for large muscles of lower extremity and trunk
- transmits weight of upper body and trunk to ischial tuberosities during sitting or to lower extremities during standing and walking
- supports organs involved with bowel, bladder and productive function
Shaft of femur displays slight:
anterior convexity
The stress along femur is dissipated through:
compression alongs its posterior shaft and through tension along its anterior shft
Bowing of femur allows:
femur to bear greater load than if femur were perfectly straight
What is the shape and configuration of developing proximal femur detemined by:
- differential growth of bone’s ossification centers
- force of muscle activation and weight bearing
- circulation
What is femoral dysplasia?
Abnormal growth and development resulting in mis-shaped proximal femur
What can affect the shape of proximal femur?
trauma or other acquired factors
What angulations of proximal femur define its shape:
- angle of inclination
- torsional angle
What is the angle of inclination?
angle within frontal plane b/w femoral neck and medial side of femoral shaft
What is the angle of inclination at birth?
140 to 150 degrees
What is the normal adult angle of inclination?
125 degrees
Cox vara:
less than 125 degrees
Cox valga:
greater than 125 degrees
What does angle of inclination affect?
alters articulation between femoral head and acetabulum affecting hip mechanics
What can severe malalignment lead to?
dislocation or stress-induced degeneration of hip joint
What does femoral torsion describe?
relative rotation between bone’s shaft and neck
What is normal view of femoral neck?
from above, femoral neck projects about 15 degrees anterior to a ML axis through femoral condyles
What is normal anteversion?
femoral neck projects about 15° anterior to a ML axis through femoral condyles
What does normal anteversion and angle of inclination afford?
optimal alignment and joint congruence
Angle of torsion between neck and shaft of femur can be:
- normal anteversion
- excessive anteversion
- retroversion
What can excessive anteversion increase?
the likelihood of hip dislocation, articular incongruence, increased joint contact force and increased wear on articular cartilage
*all can lead to OA of hip
What can excessive anteversion in children lead to?
abnormal gait pattern called in-toeing
What is in-toeing?
a walking pattern with exaggerated posturing of hip internal rotation
What is the amount of in-toeing related to?
amount of femoral anteversion
In-toeing is a:
compensatory mechanism used to guide excessively anteverted femoral head more directly into acetabulum
Internal rotated position can lead to:
shortening of internal rotator muscles and ligaments
Shortening of internal rotator muscles and ligaments can reduce:
external rotation and ROM
What is seen in persons with cerebral palsy?
excessive femoral anteversion of 25-45 degrees
In anatomic position, how does the acetabulum project?
laterally from the pelvis with varying amount of inferior and anterior tilt
What are the two measurements used to describe extend to which acetabulum naturally covers and helps secure femoral head:
- center-edge angle
2. acetabular anteversion angle