Hip Complex Flashcards
Hip Joint
Coxofemoral Joint
OR
Femoroacetabular Joint
Hip does what
Support weight of head, arms, trunk (HAT)
Structured primarily to serve weightbearing function
Hip joint articulation
Acetabulum of pelvis
AND
Head of femur
Hip Joint Classification
Diarthrodial
Synovial
Ball-and-Socket
3 DOF
Hip Osteokinematics
Flexion/Extension
Abduction/Adduction
Medial(IR)/Lateral(ER) rotation
Hip Open-packed Position
30 deg Flexion, 30 deg ABd, slight ER
Hip Closed-packed Position
Max extension, slight ABd, IR
Proximal Joint structure:
Pelvis 3 Bones
Ilium (2/5ths)
Ischium (2/5ths)
Pubis (1/5th)
All contribute/create to acetabulum
Full ossification of the pelvis happens between what ages?
20-25 years
Proximal Joint structure:
Acetabulum
Lunate surface
Acetabuluar notch
Acetabular fossa
Proximal:
Lunate surface
Horseshoe-shaped
Covered in a hyaline cartilage
Only to articulate with head of femur
Allows contact stress to be evenly distributed
Proximal:
Acetabular notch
Inferior aspect of the lunate surface
Transverse acetabular ligament-fibrous band connecting 2 inferior ends of lunate surface
Creates a fibro-osseous tunnel to acetabular fossa (fibroelastic fat covered with synovial membrane)
Proximal:
Acetabular fossa
Deepest aspect
Does NOT articulate with femoral head
Proximal:
Normal orientation of acetabulum
Faces lateral, inferior, slightly anterior*
Proximal:
Center edge angle of the acetabulum
Measures depth of acetabulum in the frontal plane
Normal: 25-40 degrees
Proximal:
Acetabular Dysplasia
<25 degrees
Abnormally shallow acetabulum
Lack of coverage of femoral head
Can lead to:
-Instability of the hip
-Increased loading of superior acetabular rim
Proximal:
Coxa Profunda/Acetabular Protrusio
> 40 degrees
Acetabulum excessively covers the femoral head
Can lead to:
-Mechanical ROM restriction
-Impingement between femoral head-neck junction and acetabulum
Proximal:
Anteversion
Acetabulum is positioned anteriorly in the transverse plane
More anteversion or less inclination:
Instability
Proximal:
Retroversion
Acetabulum is positioned posteriorly in the transverse plane
Distal:
More retroversion or more inclination:
Over coverage and impingement between acetabulum femoral head-neck junction
What does all of the acetabular abnormalities lead to?
Pathologies, including excessive cartilage wear and osteoarthritis
Proximal:
Acetabular Labrum
Wedge-shaped fibrocartilage ring
Attached to outer periphery of acetabulum by calcified cartilage
Nerve endings present:
-Proprioception (enhance stability)
-Pain (source/signal)
Transverse Acetabular Ligament
What happens when the labrum is compromised?
Friction stresses increases, deterioration of articular cartilage of hip joint =osteoarthritis
Proximal:
Functions of the acetabular labrum
Deepens socket
Increases concavity = femur head+acetabulum
Acts as a seal = stability
An abnormal shallow acetabulum increases what?
Stress on the surrounding capsule and labrum
Proximal:
Transverse Acetabular Ligament
A continuation of the acetabulum labrum
Serves as a tension band between anteroinferior and posteroinferior aspects of acetabulum
Protects blood vessels that travel beneath it
Acetabular labral tears are increasingly recognized as a source of:
hip pain and as a starting point for degenerative changes at the acetabular rim
What are some of the potential symptoms of a torn labrum?
anterior groin pain, clicking, locking, catching, instability, giving way, or joint stiffness
Distal Joint structure:
Femur
Head of femur
Neck of femur
Shaft of femur
Distal:
Head of femur
Covered in hyaline cartilage
2/3 of a sphere
Fovea- roughened pit serves as attachment site for ligamentum teres
Ligamentum teres-ligament of the head of the femur
T/F The radius of curvature of the femoral head is smaller in women than in men in comparison with the dimensions of the pelvis
True
Distal:
Neck of femur
Angulated so that the femoral head faces medially, superiorly, and anteriorly
Distal:
Angle of Inclination
Frontal plane
Between axis through femoral head & neck and longitudinal axis of femoral shaft
Normal: 125 degrees
T/F Women have a larger angle of inclination than men.
False; the angle of inclination is somewhat smaller than it is in men, owing to the greater width of the female pelvis.
Distal:
Coxa Valga
Pathological INCREASE >125 deg
Creates “longer limb”
Can be associated with:
-Decreased length of hip ABD MA
-Decreased joint instability (less articular surface contact) =can result in hip dislocation
Distal:
Coxa Vara
Pathological DECREASE <125 deg
Creates a “shorter limb”
Can be associated with:
-Increased length of hip ABD MA
-Increased joint stability (more coverage)
SN: Shear, bending forces =likely to Fx
Distal:
What can coxa vara and valga lead to?
abnormal lower extremity biomechanics
altered muscle function
gait abnormalities that contribute to pathologies such as labral pathology, hip and knee osteoarthritis, and slipped capital femoral epiphysis
Slipped capital femoral epiphysis (SCFE)
Common adolescent hip disorder; weightbearing forces may slide the femoral head inferiorly.
Surgical intervention - complication of an unstable femoral epiphysis
Distal:
Angle of torsion
Transverse plane
Axis through femoral head and neck and an axis through distal femoral condyles
Normal: 10-20 degrees ANTEVERSION in adults
Distal:
Femoral anteversion
Pathological increase >20 deg
Reduces joint stability
Distal:
Femoral retroversion
Pathological decrease <15 deg
Excessive and decreased femoral anteversion in toe type gait
Excessive anteversion = Toe in
Decreased anteversion = Toe out
Distal:
Accessory structures
~Joint Capsule
-Longitudinal fibers: attached proximal acetabular rim and labrum
-Oblique fibers: form collar around the femoral neck
-Zona orbicularis: Prevents distraction
-Thicker anterosuperior, weaker posteroinferior
Distal:
Accessory structures
~Femoral neck: intracapsular
~Greater and lesser trochanters: extracapsular
Distal:
Accessory structures
~Synovial membrane: lines capsule
-Retinacular fibers: carry blood vessels to supply head and neck
Distal:
Accessory structures
~Bursae
-3 commonly described and associated with their corresponding musculature
Distal:
Ligamentum Teres
Location: Acetabular notch | Fovea of femur
Function: Blood supply to femoral head | Checks hip rotation at >90 deg hip flexion
Distal:
Iliofemoral (“Y”) Ligament
Location: Apex-AIIS | Intertrochanteric line of femur
(Anterior; inverted Y)
Function: Checks excessive ER
Distal:
Pubofemoral Ligament
Location: Pubic portion of acetabular rim | Blends w/ iliofemoral and ischiofemoral ligaments
(Anterior)
Function: Controls ER in an extended position
Distal:
Ischiofemoral Ligament
Location: POSTERIOR acetabular rim | Fibers spiral around femoral neck | Blend w/ capsule and insert on inner surface of greater trochanter
Function: Primary restraint to IR
Optimal articular contact occurs with combined:
flexion, abduction, and lateral rotation (ER)
When is the capsuloligamentous tension least?
The capsuloligamentous tension at the hip joint is least when the hip is in mid-range flexion, slight abduction, and mid-rotation.
Distal:
Structural Adaptations of Femur
~Trabecular systems
-Line up in femur along lines of stress
-Structural scaffolding
Distal:
Medial Trabecular system
-Medial cortex of upper femoral shaft
-Oriented along vertical COMPRESSIVE forces
Distal:
Lateral Trabecular system
-Lateral cortex of upper femoral shaft
-Oblique orientation in response to SHEAR forces
Distal:
Trabecular Secondary Systems
~Secondary systems: Compressive (med) and Tensile (lat)
~Femoral neck: Zone of weakness
Hip Joint
Open Kinetic Chain
Convex femoral head
ON
Concave acetabulum
=Opposite Roll + Glide
Hip Joint
Closed Kinetic Chain
Concave acetabulum
ON
Convex femoral head
=Same Roll + Glide
Hip flexion Arthrokinematics
in Open Kinetic Chain
In sagittal plane
Anterior roll
Posterior glide
Hip Extension Arthrokinematics
in Open Kinetic Chain
In sagittal plane
Posterior Roll
Anterior Glide
Hip ABduction Arthrokinematics
in Open Kinetic Chain
In frontal plane
Superior Roll
Inferior Glide
Hip ADduction Arthrokinematics
in Open Kinetic Chain
In frontal plane
Inferior Roll
Superior Glide
Hip Internal Rotation (IR) Arthrokinematics
in Open Kinetic Chain
In transverse plane
Anterior Roll
Posterior Glide
Hip External Rotation (ER) Arthrokinematics
in Open Kinetic Chain
In transverse plane
Posterior Roll
Anterior Glide
Pelvic Anterior Tilt Arthrokinematics
in Closed Kinetic Chain
In sagittal plane / coronal axis
BIL Hip flexion if standing on both legs
Hip flexion only on WB leg when SLS
Pelvic Posterior Tilt Arthrokinematics
in Closed Kinetic Chain
In sagittal plane / coronal axis
BIL Hip extension if standing on both legs
Hip extension only on WB leg when SLS
Lateral Pelvic Tilt Arthrokinematics
in Closed Kinetic Chain
In frontal plane / A-P axis | SLS WB is axis; Non-WB is where movement happens
Pelvic Hike:
On Right = Left Hip ABd
On Left = R Hip ABd
Pelvic Drop:
On Right = Left Hip ADd
On Left = R Hip ADd
Lateral Shift of Pelvis Arthrokinematics
in Closed Kinetic Chain
In frontal plane / A-P axis| BIL WB | Pelvic drop
R Pelvic Shift:
Right hip ADd
Left hip ABd
L Pelvic Shift:
Right side ABd
Left side ADd
Forward / Backward Pelvic Rotation
In transverse plane / longitudinal axis | Axis is the WB Leg
Forward Rotation:
Right around Left = Medial rotation of Left Hip
Left around Right = Medial rotation of Right Hip
Backward Rotation:
Right around Left = Lateral rotation of Left Hip
Left around Right = Lateral rotation of Right Hip
Pelvi-femoral Rhythm
Open kinetic chain
Continuous relationship between femur, pelvis, and spine to increase overall available ROM for distal segment
Lumbopelvic Rhythm
Closed kinetic chain
Continuous relationship between spine, pelvis, and femur to increase overall available ROM for distal segment
What are some examples of activities where the hip support HAT?
Static erect posture and dynamic postures like:
-ambulation/gait
-running
-stair climbing
Hip joint structure is influenced more by what?
By the demands placed on the joint when the limb is bearing weight
How many muscles cross the hip?
9; rectus femoris, iliacus, psoas major, tensor fascia latae, sartorius, pectineus, adductor longus, adductor magnus, and gracilis
The major muscles that contribute most of the flexion torque
the rectus femoris, iliopsoas, tensor fascia latae, and sartorius
Muscles assisting with hip flexion
the pectineus, adductor longus, adductor magnus, and gracilis
The hip adductor muscle group lies on the anteromedial aspect of the thigh and includes
the pectineus, adductor brevis, adductor longus, adductor magnus, and the gracilis muscles.
The primary hip extensors cross the joint posteriorly and include
the one-joint gluteus maximus muscle and the two-joint hamstrings muscle group (LH biceps femoris, semitendinosus, and semimembranosus)
Muscles assisting hip extension
the posterior fibers of the gluteus medius, from the posterior fibers of the adductor magnus muscle, and from the piriformis muscle
The prime muscles responsible for producing hip abduction lie on the lateral side of the joint and include
the gluteus medius and gluteus minimus muscles.
Muscles assisting hip abduction
The superior fibers of the gluteus maximus, the sartorius, and the tensor fascia lata muscle only during simultaneous hip flexion.
What are the 6 short muscles function primarily as lateral rotators of the hip joint and pass posterior to the joint axis in a mediolateral direction.
obturator internus and externus, the gemellus superior and inferior, the quadratus femoris, and the piriformis muscles.
What are the primary muscles producing medial rotation of the hip?
There are no muscles with a primary function of producing medial rotation of the hip joint. The more consistent medial rotators are the anterior portion of the gluteus medius, gluteus minimus, and the tensor fascia lata muscles.
When bilateral stance is not symmetrical, what muscle activity will be necessary either to control the side-to-side motion or to return the hips to symmetrical stance?
frontal plane muscle activity (abd/add; mainly abd)
What happens if inadequate abduction torque is created (e.g., from a weakened gluteus medius)?
the pelvis will drop on the contralateral side.
In a unilateral stance, what needs to be active in order to keep the pelvis level?
Hip abductors must be active
Compensatory Lateral Lean of the Trunk
Reduces MA of the gravitational force by shifting the line of gravity closer to the hip joint
