Pathophysiology of the Hip

Question 1

Acetabulum orientation

Answer 1

• Lateral
• Slightly inferior
• slightly anterior

Question 2

Proximal femur angle of inclination and torsion

Answer 2

125 degree angle of inclination
- coxa vera= narrower than that
- coxa valga= wider than that
Angle of torsion
- anterversion
- retroversion

Question 3

Hip fracture facts

Answer 3

• 5% of falls result in fractures
• one of every 6 white women will have a hip fx in their lifetime
  
  • 90% in persons 65+
• risk for hip fx increases with age
• because of increasing number of elderly in US, total number of hip fractures in people 50+ will rise from 238,000 to 512,000 by year 2040

Question 4

hip fracture costs

Answer 4

• the annual cost of hip fractures will increase from approx 7.2 billion to 16 billion in year 2040

Question 5

Hip fracture prognosis

Answer 5

• Approximately 4% of people die after hip fracture b/c of complications from the fx, its surgical tx, or from medical consequences from being immobilized
• about 25% people over 64 y/o die within 1 year
• 10% become functionally dependent

Question 6

Types of hip fractures

Answer 6

Femoral shaft fracture- extracapsular
intertrochanteric- extracapsular
femoral neck fracture- intracapsular

Question 7

Zone of weakness

Answer 7

between trochanters

Question 8

Femoral neck fractures

Answer 8

• very difficult fx to manage
• most common in adults > 60 years of age
• more common in females than males

Question 9

Garden’s classification of intracapsular fractures of femoral neck

Answer 9

• Type I: incomplete
• Type II: complete but undisplaced
• Type III: partially displaced
• Type IV: completely displaced
• *types III & IV have high incidence of avascular necrosis of femoral head

Question 10

Femoral neck fracture medical surgical management

Answer 10

ORIF

Question 11

Hip bursitis etiology

Answer 11

• Direct blow or impact in area of greater trochanter

- friction due to overuse (running)

Question 12

Hip bursitis clinical picture

Answer 12

Pain on outside of hip

• may worsen with physical activity such as running
• pain upon palpation at greater trochanter
• intense pain and swelling near greater trochanter
• Pain that travels down the thigh at night
• bursa can refer
• also could be lumbar spine

Question 13

Hip bursitis medical management

Answer 13

• Rest> self limiting
• aspiration of bursa
• anti-inflammatory meds
• steroid injection + rest
• orthotic prescription

Question 14

Hip traumatic dislocation

Answer 14

May dislocate in anterior or posterior direction

- posterior more common

Question 15

Hip traumatic dislocation MOI

Answer 15

• MVA: dashboard injury

- fall onto flexed knee

Question 16

Avascular necrosis of femoral head

Answer 16

• blood supply to femoral head and neck cut off

- tear of ligamentum teres can cause this

Question 17

Congenital/developmental pathophysiology of the hip

Answer 17

• Developmental dysplasia of the hip (DDH)
• congenital hip dislocation, infantile hip dislocation, congenital dislocation of the hip (CD)
• slipped femoral capital epiphysis
• Legg-Perthes Disease

Question 18

Congenital hip dislocation incidence

Answer 18

• .25 to .85% of newborns
• 8:1 M:F
• most unilateral
• usually on the left

Question 19

Congenital hip dislocation etiology

Answer 19

• Perinatal or post natal
• ligamentous laxity of jt capsule
• breech presentation at birth

Question 20

Congenital hip dislocation clinical picture

Answer 20

• 90% will stabilize with first 2 months of life

- cannot predict who would and who would not stabilize so must treat them all

Question 21

Congenital hip dislocation medical/surgical management

Answer 21

Bracing helps position head of femur correctly in acetabulum

Question 22

Congenital hip dislocation physical signs

Answer 22

• Asymmetry in ROM, gluteal folds, thigh folds
• leg length discrepancy
• trendelenburg
• flexion contractures

Question 23

Developmental dysplasia of the hip

Answer 23

• abnormal development of cells
• children with spasticity, downward pull of iliopsoas (IS) and adductor muscles initiate force
• when over-activity and contraction of IS occurs, medial joint capsule is compressed and femoral head is pushed laterally
• as the lateral drift of femoral head occurs the IS insertion on lesser tubercle becomes the center of rotation
• acetabular development ceases when femoral head is completely displaced laterally
• further hip flexion pushes the head posteriorly to complete the dislocation

Question 24

Slipped femoral capital epiphysis description

Answer 24

Unusual disorder of adolescent hip characterization by a posterior slippage of the head of the femur

Question 25

Slipped femoral capital epiphysis etiology

Answer 25

Weakness of the growth plate, may occur shortly after puberty

Question 26

Slipped femoral capital epiphysis clinical picture

Answer 26

• xrays confirm diagnosis
• typical antalgic gait
• reluctance to weight bear

Question 27

Slipped femoral capital epiphysis medical/surgical management

Answer 27

ORIF

Question 28

Legg-Calve-Perthes osteochondrosis of femoral head

Answer 28

• Epiphyseal aseptic necrosis of proximal head of femur

- slipped capital epiphysis

Question 29

Legg-Calve-Perthes etiology

Answer 29

• unknown and insidious onset
• 1/1200 children between ages 3-12
• Primarily affects white males (4x > females)

Question 30

Legg-Calve-Perthes pathophysiology

Answer 30

• Predictable, self-limiting course during a 12-36 month period
• lack of blood to femoral head leads to aseptic necrosis with softening and resorption of bone
• revascularization results in reossification
• Four stages: synovitis, avascular, regeneration, resorption

Question 31

Legg-Calve-Perthes impairments

Answer 31

• Pain in groin, thigh, and knee, especially with walking and running, antalgic gait
• decreased ROM and atrophy of gluteal and thigh musculature

Question 32

Legg-Calve-Perthes clinical implications

Answer 32

• without treatment femoral head may become flattened
• resolves with little hip deformity if treated appropriately
• goal is to limit deformity by preventing stress on femoral head and keeping it within joint capsule
• utilization of “A” frame, hip spica, abduction

Question 33

Pain at greater trochanter of femur

Answer 33

Pain can refer here from

• anterior, lateral, post derrangement
• stenosis
• SI joint
• have the pain with sitting> lumbar spine

Question 34

Differential diagnosis

Answer 34

• Past medical/ surgical
• diagnostic imaging
• night pain
• sequence of diagnostic movements