The Hip Joint

Normal femoral angle

125

•In conjunction with a normal angle of inclination (____) a ___° _______ angle affords optimal joint alignment and joint congruence

125 15 anteversion

normal femoral anteversion angle is

15

normal acetabular anteversion angle

20 degrees

in kids the normal femur angle is ______ but it does reduce

40

retroversion

< 8 degrees

excessive anteversion

> 15 degrees

In-toeing

A walking pattern with exaggerated posturing of LE internal rotation This may be done as a compensation to guide the excessively anteverted femoral head more directly into the acetabulum

hip

Classic ball and socket joint of the body contains articular cartilage that forms the load bearing surface of the joint

center edge angle

Indicates the degree to which the acetabulum covers the femoral head can vary average: 25-35 deg

acetabular anteversion angle

Measures the extent to which the acetabulum projects anteriorly within the horizontal plane how much rotation is present

femoral torsion

The relative rotation (i.e. twist) between the femoral shaft and neck

advantages and disadvantages of coxa valga

advantages: -femoral neck can withstand higher forces (less neck fractures) -lengthen the hip abductor muscles (greater ROM) disadvanatges: -reduced moment arm -more force needed (more muscle issues) -less stable (dislocations)

advantages & disadvantages of coxa vera

advantages: -moment arm increased -associates w/ joint stability disadvantages: -excessive forces produced through femoral neck (fracture) -reduce length of hip abductor muscles

what two things help with optimal joint alignment and joint congruence

angle of inclination and anteversion

•Normally, the center of femoral head projects _________ to a _________-_________ axis through the femoral condyles

anterior medial-lateral

with increased acetabular anteversion angle

hip is exposed more anteriorly more prone to anterior dislocation and anterior labrial lesion ESPECIALLY IN LATERAL ROTATION

coxa valga

increased angle of inclination >125 excessive >150

hip liagments

ischiofemoral pubofemoral iliofemoral (y ligament)

coxa vara

less than 125 degrees of angle of inclination excessive <90

femoral angle of inclination

the angle in the frontal plane b/w the femoral neck and medial side of the femoral shaft

center edge angle measures...

the fixed orientation of the acetabulum within the frontal plane relative to the pelvis

excessive coxa valga

very common in children with cerebral palsy & hip dysplasia

acetabular labrum

• Fibrocartilage ring that surrounds the outer rim of the acetabulum •Adds stability to the hip by "gripping" the femoral head and deepening the volume of the socket by ~ 30% •Helps maintain a negative intra-articular pressure and holds the synovial fluid •Reduces contact stress by increasing the surface area of acetabulum

iliofemoral ligament

•Also referred to as the "Y ligament" •Strongest and stiffest ligament of the hip •Resist further hip ext •Becomes taught in: •Full hip extension, external rotation, and adduction

Ishiofemoral Ligament

•Becomes taut in: •Full extension, abduction, and internal rotation

Pubofemoral Ligament

•Becomes taut in: •hip abduction, extension, and external rotation

high center edge angle

•excessive acetabular enveloping of femoral head •Can cause pincer type impingement and loss of hip ROM

low center edge angle

•reduced acetabular enveloping of femoral head •More unstable AND less contact area within the joint