Week 12: Hip Joint Assessment and Pathologies

What is the normal angle of inclination of the hip joint in adults?

125°.

Angle of Inclination of the Hip

Occurs in frontal plane between femoral neck and medial shaft

Angle of inclination at birth

16-170

angle of inclination decreases by how much per year

2 degrees

What is Coxa Vara and its angle of inclination?

Coxa Vara is an angle of inclination less than 125°, with the distal segment toward the midline.

What is Coxa Valga and its angle of inclination?

Coxa Valga is an angle of inclination greater than 125°, with the distal segment away from the midline.

Femoral torsion

rotation/twist between femoral shaft & femoral neck

What is the normal range for femoral torsion?

8-20º.

normal anterversion

8-20 degrees

angle of torsion at birth

40 degrees

What is excessive anteversion and its angle?

Excessive anteversion is defined as greater than 15°.

femoral retroversion

external rotation of femur angle less than 15

What are some consequences of excessive anteversion?

Dislocation risk, joint incongruence, increased joint contact stress, wear on cartilage and labrum, and potential arthritis.

What gait pattern is associated with excessive anteversion?

In-toeing gait pattern.

How does excessive anteversion affect hip abductors?

It increases the moment arm for hip abductors but reduces leverage.

in-toeing hip ligaments

reduced Hip ER capacity

Children with Cerebral Palsy may have

excessive anteversion

Surgery for excessive anteversion

femoral de-rotational osteotomy

When femoral head is positioned more anteriorly

We will have more IR than ER with the hip in neutral

What is the role of the ligamentum teres in the hip joint?

It houses the acetabular artery and stabilizes the hip via proprioception.

ligamentum teres is stretched by

ER & IR combined with flexion; also adduction

ligamentum teres houses

Mechanoreceptors that stabilize ligamentum teres via proprioception

What is the thickest part of the cartilage on the femoral head?

The thickest cartilage is superior/anterior to the fovea.

What is the function of the acetabular labrum?

It grips the femoral head, deepens the socket, helps with stability, creates a suction-seal, and enhances lubrication of cartilage.

suction-seal of the labrum

Resists distraction

Keeps fluid from leaking by fluid seal

Enhances lubrication of cartilage

Reduces friction

labrum has a poor

blood supply

labrum has a good

nerve supply

What is the significance of the lunate surface in the acetabulum?

It is the thickest cartilage area where the femoral head connects and corresponds to the highest weight-bearing phase of gait.

What happens to hip forces during the mid-stance phase of gait?

Hip forces can exceed 300% during mid-stance.

What is the role of the transverse acetabular ligament?

It completes the inferior portion of the acetabular labrum.

symptoms of labral tears

may have no symptoms, may have groin pain, may have catching or popping, pain with twisting, motion loss

normal acetabular position

inferior & anterior

At what age does the angle of femoral torsion drop to about 15°?

By age 16.

What is the role of mechanoreceptors in the ligamentum teres?

They stabilize the ligamentum teres via proprioception.

What is the impact of hip flexion on the femoral head position?

Flexion can cause impingement against the acetabulum when the femoral head is positioned more anteriorly.

What is the typical progression of angle of inclination from birth to adulthood?

At birth, it is 165-70º, reducing to 125° in adulthood.

What is the significance of the acetabular labrum's poor blood supply?

It leads to poor healing

What is the starting point for degeneration in acetabular labral tears?

The acetabular rim.

Are isolated labral tears common?

No, they are uncommon and usually occur with bony abnormalities of the acetabulum or femoral-neck junction.

What is the normal position of the acetabulum?

Inferior and anterior.

What does the Center Edge Angle measure?

The degree of femoral head coverage by the acetabulum in the frontal plane.

What is the normal range for the Center Edge Angle?

25-35°.

What happens if the Center Edge Angle is too low?

It leads to reduced femoral head coverage, instability, subluxation, dislocation, and increased contact pressure.

What are the consequences of a too high Center Edge Angle?

Increased femoral head coverage, leading to impingement and injury.

What does the Acetabular Anteversion Angle indicate?

The degree that the acetabulum faces anteriorly.

What is the normal Acetabular Anteversion Angle?

20°.

What happens if the Acetabular Anteversion Angle is excessive?

It reduces femoral head coverage and increases vulnerability to anterior subluxation or dislocation during external rotation movements.

If acetabular anteversion angle is close to zero or negative, the retroverted acetabulum can create

abnormal stress on the joint interface

Retroversion increases

femoral head coverage

What is the typical treatment for Hip Dysplasia in childhood?

"Frog-leg" positioning with a harness to improve articular contact and congruence.

frog leg position

Combined flexion, abduction and rotation

What factors contribute to increased articular stress and degeneration in Hip Dysplasia?

Increased articular stress leads to degeneration and osteoarthritis (OA).

Which factor is most significantly associated with arthritis in the hip?

The center edge angle.

What ligaments reinforce the hip joint capsule?

Iliofemoral, ischiofemoral, and pubofemoral ligaments.

What is the strongest and stiffest hip ligament?

Iliofemoral ligament.

Y ligament of Bigelow

iliofemoral ligament

What position stretches the iliofemoral ligament?

Full external rotation and extension.

When standing with the hip fully extended the anterior femoral head pushes against

iliofemoral ligament and iliopsoas

Hip Abduction + Extension (& ER) stretches

Pubofemoral ligament

Hip IR (+10-20° abduction) stretches

Ischiofemoral ligament

CPP of hip

extension, IR, abduction

max congruence of hip joint

90° flex, mod. Abduction, & ER

Hip OPP

30 flexion, 30 abduction, slight ER

What position is the hip in during terminal stance of gait?

Full extension, slight internal rotation, and abduction.

What is the intracapsular pressure in a healthy hip?

Less than atmospheric pressure, which causes suction.

What happens to pressure in the hip joint during extremes of range of motion (ROM)?

Pressure stays low, except at extremes of ROM (flexion and extension). It is lowest in the middle of the ROM.

What can prolonged flexed posture lead to in the hip joint?

Prolonged flexed posture can cause a contracture.

What is the effect of capsular swelling on pressure throughout the hip joint's ROM?

Capsular swelling leads to increased pressure throughout the ROM.

How is the gluteus maximus affected by joint effusion?

The gluteus maximus is inhibited with joint effusion.

What is the difference between femoral-on-pelvic motion and pelvic-on-femoral motion?

Femoral-on-pelvic motion is open chain with the femur rotating and the pelvis fixed, while pelvic-on-femoral motion is closed chain with the pelvis rotating and the femur fixed.

What are the three degrees of freedom in hip kinematics?

1. Flexion/Extension in the sagittal plane (medial/lateral axis), 2. Abduction/Adduction in the frontal plane (A-P axis), 3. Internal/External Rotation in the horizontal plane (vertical axis).

Extramedullary

outside the bone marrow

What limits hip flexion in the sagittal plane?

Hip flexion is limited by the posterior-inferior capsule.

What occurs during full hip flexion?

Full flexion involves anterior pelvic tilt and lumbar flexion.

What structures limit hip extension?

Hip extension is limited by the anterior capsule, iliofemoral ligament, and hip flexors.

What limits hip abduction in the frontal plane?

Hip abduction is limited by the pubofemoral ligament and adductors.

What limits adduction of the hip?

Adduction is limited by hip abductors, piriformis, and the iliotibial band (ITB).

What limits internal rotation (IR) of the hip?

Internal rotation is limited by external rotators (ERs) and the ischiofemoral ligament.

What limits external rotation (ER) of the hip?

External rotation is limited by the iliofemoral ligament and internal rotators.

What is ipsidirectional lumbopelvic rhythm?

occurs when the pelvis and lumbar spine rotate in the same direction.

What is contradirectional lumbopelvic rhythm?

occurs when the pelvis and lumbar spine rotate in opposite directions, allowing the trunk to remain stationary as the pelvis rotates.

What is the significance of lumbopelvic dissociation?

allows for independent movement of the pelvis and trunk, which is important during activities like walking.

Lumbar spine acts as a decoupler to allow

the pelvis and trunk to move independently

pelvic rotation is named by

iliac crest as it moves around the M-L axis

How does pelvic rotation in the sagittal plane with flexion affect the lumbar spine?

anterior pelvic tilt, which slackens the iliofemoral ligament and increases lumbar lordosis.

What happens to the pelvis during hip flexion in a sitting position?

normal adult can perform about 30º of additional pelvic on femoral hip flexion before being restricted by an extended lumbar spine.

What is the effect of tight hamstrings on pelvic motion?

Tight hamstrings can limit anterior pelvic tilting.

What occurs during hip extension in terms of pelvic motion?

a posterior pelvic tilt, flexes the lumbar spine, and reduces lumbar lordosis.

What is the role of the support hip during pelvic rotation in the frontal plane?

The weight-bearing extremity acts as the support hip, raising the iliac crest on the contralateral side during abduction.

Hip abduction in frontal plane doe what to the pelvis

Raises the iliac crest on the contralateral side in closed chain

Hip abduction moves femur

away from midline

What restricts hip abduction in a closed chain?

restricted by tightness in ipsilateral adductors or the pubofemoral ligament.

How does the lumbar spine move during pelvic rotation in the horizontal plane?

The lumbar spine must move in the opposite direction of pelvic rotation.

Hip adduction closed chain iliac crest

Iliac crest ipsilaterally elevates

Hypomobile or painful lumbar, or limited mobility in IT band spine may limit extremes of

adduction

IR of the support hip occurs as what

the contralateral iliac crest moves forward in the horizontal plane

ER, the contralateral iliac crest moves

backwards on fixed femur

ER Pelvic R rotation=

Lumbar left rotation

What is the arthrokinematics of hip abduction in the frontal plane open chain

femoral head rolls superiorly and slides inferiorly.

Hip adduction arthrokinematics open chain

inferior roll, superior glide