Acetabulum orientation
ventromedially to dorsolaterally in teh transverse plane and carniolaterally to caudomedially in teh frontal plane
Collodiaphyseal angle
starts at 150* from the femoral diaphysis at birth and decreases to 120-130 by adulthood due to WB
CD angle <120
coxa vara - can result in potential shearing stresses that damage the epiphyseal plate of femoral head
Excessive CD angle
-coxa valga - can lead to altered muscle activity and intraarticular forces in the CFJ as well as altered cartilage response
CFJ
Coxafemoral joint
Center edge angle
-is the angle between the acetabulum and the femoral head in teh frontal plane
Center edge angle
30*
Center edge angle <30*
means dysplastic changes in teh joint
Anterior rotation of femoral neck changing over a lifetime
goes from 40* to 9* from the line between the distal femoral epicondyles
Anteversion
Retrotorsion (retroversion)
Cartilage and the humeral head
2/3 covered in hyaline cartilage
-center lacks cartilage to allow insertion of teres ligament and neurovascular supply
Gothic arch
-cartilage of acetabulum forms this - where cartilage is least developed in the far superior region of the dome and discontinuous in teh floor and anterior inferior region
Pulvinar acetabuli
-layer of fat found on the floor of the acetbulum that migrates out with change sin pressure
Where is cartilage most developed in the acetabulum?
In the anterior and posterior superior surface of the gothic artch because that is where femoral head has greatest contact and loading during gait
Who experiences greater stress on cartilage - men or women?
Women - and any dysfunction in muscles around the joint could lead to increases in force imposed on joint and early degeneration
Labrum
Loss of labrum
-can produce a reduction in articular seal, fluid pressurization, load support, and joint lubrication
Vascularization of the labrum
Capsule - 3 different fiber systemes
1) longitudinal - along the length of capsule from proximal to distal creating a tensile strength
2) transverse - circular fashion around capsule at the neck creating Zona Orbicularis - region where capsule narrows
3) Arcuate fibers - loops at the proximal insertion at the labrum reinforcing the insertion
Ligamentum teres
Iliofemoral ligament
1) Pars inferioris - constrains hip extension
2) pars superioris - constrains hip ext, adduction, ER
Pubofemoral ligament
-constrains hip extension, abduction, ER
Ischiofemoral ligament
-works with the arcuate ligament to provide hip stability during quiet standing - taut in the upright position