Hip Flashcards
What is the osteology of the coxofemoral joint and what type of joint is it?
Ilium, ischium, pubis with the femur
Ball and socket
Acetabulum has a lunate surface and covered in hyaline cartilage in order to do what?
Articulates with head of femur and increases depth
What is the normal angle of inclination?
Why is this angle important?
-Serves to optimize joint surface
-Axis through femoral head/neck and longitudinal axis of femoral shaft
Normal = >125
What is coxa valga?
increase in inclination
>125
What is coxa vara?
decrease in inclination
<125
A decrease in femoral neck-shaft angle (coxa vara) or angle of inclination along with a high body mass index may result in what?
Slipped capital femoral epiphysis in adolescents
What is the angle of torsion?
occurs in transverse plane
Axis through femoral head/neck and distal femoral condyles
What is the normal degree of anteversion at the hip?
8-20 (15 optimal)
What are the ramifications of excessive anteversion?
- Increased angle of torsion
- reduce hip joint stability
- associated with increased hip IR and decreases ER
What is retroversion?
- Decreased angle of torsion
- Associated with increased hip ER and decreased IR
- May cause impingement
What are the ramifications of Excessive retroversion?
- Excessive anteversion in children may be associated with “in-toeing” gait
- This is a compensation that aims to improve joint congruency (see red dots)
- Overtime this may cause shortening of muscles and ligaments crossing hip and reduced ER of the hip
What are some common acetabular abnormalities?
Acetabular dysplasia - shallow acetabulum
Coxa profunda/acetabular overcoverage - acetabulum excessively covers the femoral head
What is the difference between a CAM lesion and a pincer lesion in regards to hip impingement?
CAM - extra bone on the femoral head
-Impingement occurs on bulge of femoral head against acetabulum
-IR with flexion max impingement
Pincer - extra bone of anterior-lateral rim of acetabulum
-Flexion and IR causes premature abutment of femur against acetabulum
What is the bending moment of the femur?
Superiorly - tensile forces
Inferiorly - compressive forces
What are the trabecular systems?
- Provide structural resistance
- Strongest where they cross at right angles
- Zone of weakness = thin and do not cross
What structures provide stability at the hip joint?
Hip joint capsule -
- Substantial contributor to hip joint stability
- Thickened anterosuperiorly (predominate stress occurs)
What structures provide stability at the hip joint?
Iliofemoral
- Anterior stability
- Controls IR/ER
- Tighten with hyperextension
What structures provide stability at the hip joint?Pubofemoral -
- Controls ER in ext
- Tighten with hyperextension
What structures provide stability at the hip joint?
Ishiofemoral -
- Restraint to IR
- Tighten with hyperextension
What structures provide stability at the hip joint?
Transverse acetabular ligament -
Protects blood vessels that travel beneath to head of femur
What structures provide stability at the hip joint?
Acetabular labrum -
- Wedge shaped
- Deepens concavity
- Seal to maintain (-) intra articular pressure
What structures provide stability at the hip joint?
Ligamentum Teres -
- Blood supply to femoral head
- Excessive ER can strain/tear
Describe the osteo of the hip joint.
Flex/ext
Abd/Add
Er/IR
Describe the arthrokinematics of the hip joint.
Flex - Ant roll/post glide Ext - Post roll/ant glide Abd - Superior roll/inferior glide Add - Inferior roll/superior glide IR - Anterior roll/posterior glide ER - Posterior roll/anterior glide
