Chapter 46- The Child's Hip Flashcards

1
Q

In a child with a trendelenberg limp, what is the limp diagnostic calendar

A
  • 1-5 years- missed congenital dislocation of the hip
  • 5-10 years- perthes disease
  • 10-15 years- slipped upper femoral epiphyses
  • septic arthritis and transient synovitis of the hip can present at any age
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2
Q

What is developmental dysplasia of the hip

A
  • idiopathic hip dysplasia
  • it includes dislocation at birth and acetabular dysplasia where the hip is located, patient becomes symptomatic later in life because acetabulum has not developed normally
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3
Q

Ligamentous laxity contributes to developmental dysplasia of the hip. What causes ligamentous laxity

A
  • sensitivity to female perinatal hormone relaxin
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4
Q

Mechanical factors contributing to developemental dysplasia of the hip

A
  • in utero: increased incidence in Breech, first born and oligohydramnios
  • Postnatal: swaddling eg by native americans
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5
Q

Pathology of developmental dysplasia of the hip

A

Hip dislocates supero-laterally and capsule develops in an hourglass deformity with the inferior capusle being the main obstruction to reduction. Acetabulum becomes more dysplastic with deficient antero-lateral cove.

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6
Q

Describe the tests done in the neonatal period to test for hip instability

A
  • Ortolani: dislocated hip relocates with abduction of the hip
  • Barlow: hip located but unstable and dislocates with adduction
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7
Q

What test is indicated in patients at high risk for developmental dysplasia of the hip and when is the ideal time for this test

A
  • Ultrasound (more sensitive than clinical exam)

- Ideal time is at 6 weeks

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8
Q

Describe a patient at high risk for developmental dysplasia of the hip

A
  • positive family history
  • First born
  • Breech
  • Barlow positive hip
  • any ‘suspicious’ hip
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9
Q

Describe the AP pelvis radiograph in developmental dysplasia of the hip

A
  • Femoral epiphyses only apparent at 6 months, therefore special lines are required to show superolateral dislocation.
  • Shenton’s line (joining inferior femoral neck with inferior pubic ramus) is broken
  • Metaphysis of femoral neck lies laterally to a line drawn from the lateral border of the acetabulum
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10
Q

What may an untreated dislocated hip in a child eventually lead to

A
  • Adequate treatment prevents a trendelenburg, short leg limp
  • Stiff, painful hip due to avascular necrosis is often due to treatment only
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11
Q

Treatment of dislocation based on age?

A
  • <6 months: Pavlik harness
  • 6- 18 months: traction, closed reduction and spica
  • > 18 m: Open reduction, pelvic osteotomy +- femoral osteotomy
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12
Q

What position does the pavlik harness hold the hips in?

A

-Hips in flexion and abduction but allows mobility

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13
Q

What is the complication of treatment of developmental dysplasia of the hip

A
  • Avascular necrosis
  • Caused by splinting of the hip in more than 40 degrees of abduction in the pavlik harness or spica. or with a tight open reduction (femoral shortening reduces the chance of avascular necrosis
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14
Q

Average age of presentation of SUFE

A
  • Boys: 14

- Girls: 12

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15
Q

Main complications of SUFE

A
  • Avascular necrosis

- Chondrolysis

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16
Q

What are the current theories of the cause of SUFE

A
  • Hormonal: Sex hormones close the growth plate and growth hormone increases the thickness of the growth plate, and therefore makes it weaker
  • Retroversion: Increased retroversion of the femoral neck predisposes the femoral head to slip posteriorly
  • Trauma: repetitive trauma in obese patients acting of an abnormal growth plate could be a factor
  • Hereditary
17
Q

Definite causes of SUFE

A
  • Primary hypothyroidism
  • Pituitary tumours
  • Hypogonadism
  • Renal rickets
18
Q

Clinical presentation of SUFE

A
  • Hip pain often referred to the knee
  • 50 percent are overweight
  • Antalgic, trendelenberg and possibly short limb limp
  • decreased abduction and internal rotation of the hip
  • Hip goes into external rotation when flexing because anteriorly displaced femoral neck blocks internal rotation
  • Acute slip: duration of symptoms less than 3 weeks
  • Chronic slip: Duration more than three weeks
  • Acute on chronic: sudden exacerbation of chronic symptoms
19
Q

Stable vs unstable SUFE

A
  • Stable: patient can weight bear with or without crutches. no AVN
  • Unstable: cannot weight bear with or without crutches. 10 percent develop AVN
20
Q

Findings on radiograph in SUFE (Ap and frog lateral)

A
  • AP: minimal slip shows a widened and irregular physis. An established slip has a positve Trethowan’s sign: a line along the superior aspect of the neck remains superior to the head instead of going through it.
  • Lateral radiograph: Positive Capener’s sign: femoral head lies outside the acetabulum
21
Q

How is the percentage slip determined in SUFE and how does this relate to the severity

A
  • Percentage slip is determined on lateral view by the Wilson percentage method or the head shaft angle
  • Mild: < 30% slip or 30 degrees
  • Moderate: 30- 50 % slip or 30-60 degrees
  • Severe: > 50 % slip or >60 degrees
22
Q

Treatment of mild to moderate SUFE

A

Pinning in situ is achieved by one screw placed in the centre of the epiphyses and 90 degrees to the growth plate

23
Q

Treatment of severe SUFE

A

-If slip is unpinnable, slow reduction of the hip with traction in abduction and internal rotation over a few days has a low incidence of AVN

24
Q

What is Perthe’s disease

A

-Partial or total avascular necrosis of the femoral head, in contrast to other causes of AVN, the femoral head recovers

25
Q

Etiology of perthes disease

A
  • Recurrent infarction occurs
  • Etiology is unknown
  • Blood supply from 3-10 years is limited to the lateral retinacular vessel only, the metaphyseal vessels disappear after 2 years
  • The lateral retinacular vessel is vulnerable to changes of pressure in the hip capsule
26
Q

What are the three stages of Perthes disease

A
  • Avascular stage: Femoral head can be normal. joint space is increased. Subchondral fracture occurs when trabeculae collapse. Finally the head becomes sclerotic
  • Revascularisation phase: Dead bone is removed by ‘creeping substitution and the femoral head looks cystic and fragmented
  • Healing stage: Subchondral ossification occurs. whole process up till now takes up to one year. the healing process is only completed after 2-4 years and the final shape of the head (spherical, oval or flat) becomes obvious at maturity
27
Q

Clincal presentation of Perthes disease

A
  • Antalgic and trendelenberg limp

- Decreased abduction and external rotation

28
Q

How does one classify Perthes disease according to the Catterall groups?

A

1: anterior quarter
2: Anterior half (lateral pillar intact)
3: lateral three quarters (lateral pillar involved)
4: whole head involvement

29
Q

What is the goal of treatment in Perthes disease

A

-Protect the femoral head during biologically plastic or soft stage (during avascular and revascularisation phases) and prevent it from becoming flat instead of spherical

30
Q

Definitive treatment of Perthes ?

A

Includes:

  • Containment: by abducting the hip the lateral pillar is protected by the acetabulum
  • Movement for cartilage nutrition
  • Some believe non weight bearing also plays a role
31
Q

Conservative treatment of Perthes disease

A

-Abduction plasters or splints (weight bearing and non-weight bearing) for about one year until subchondral ossification occurs and deformity of the femoral head cannot occur

32
Q

Surgical treatment of Perthes

A
  • Pelvic Osteotomy: salter (<8), Chiari, Shelf

- Femoral osteotomy

33
Q

Prognostic Factors of Perthes disease

A
  • Age ( > 8 years)

- Lateral pillar involvement