Paediatric - The Big 3

Question 1

What is the incidence of developmental dysplasia of the hip?

northern europe, eastern europe, african neonates, apaches and navajos, inuits

Answer 1

NE: 0.7-2.2 per 1000
Eastern EU: 28.7 per 1000
African neonates: 0
Apaches and navajos: 5%
Inuits: 25%

Question 2

What is the incidence of develoopmental dysplasia of the hip?

(M:F, Left: Right hip)

Answer 2

Girls 6:1

Left hip 3:1

Question 3

An increased incidence of developmental dysplasia of the hip is seen in who?

Answer 3

First born
Oligohydramnios
Breech presentation
Family history
Other lower limb deformities
Increased weight

Question 4

What are the clinical features of developmental dysplasia of the hip?

Answer 4

Ortolani’s sign
Barlow’s sign
Piston motion sign
Hamstring sign

Question 5

What percentage of DDH cases are picked up by examination?

Answer 5

Only 40%

Question 6

What is Ortolani’s sign?

Answer 6

It relocates the dislocation of the hip joint that has just been elicited by the Barlow maneuver.

It is performed by an examiner first flexing the hips and knees of a supine infant to 90 degrees, then with the examiner’s index fingers placing anterior pressure on the greater trochanters, gently and smoothly abducting the infant’s legs using the examiner’s thumbs. A positive sign is a distinctive ‘clunk’ which can be heard and felt as the femoral head relocates anteriorly into the acetabulum

Specifically, this tests for posterior dislocation of the hip.

Question 7

What is Barlow’s sign?

Answer 7

The maneuver is easily performed by adducting the hip (bringing the thigh towards the midline) while applying light pressure on the knee, directing the force posteriorly.

If the hip is dislocatable - that is, if the hip can be popped out of socket with this maneuver - the test is considered positive. The Ortolani maneuver is then used, to confirm the positive finding (i.e., that the hip actually dislocated).

Question 8

At what age on average does the head of the femur ossify?

Answer 8

Not until the child is at least 3 months old

Question 9

Describe the treatments for DDH at different ages

1yr, >1yr, >18 months, >6yrs, >10yrs

Answer 9

1yr
-Open reduction and capsule reefing

> 18months
-Open reduction with femoral shortening

> 6yrs
-Bilateral -> leave alone

> 10yrs
-Unilateral -> leave alone

Question 10

What is the typical presentation of Perthes Disease?

Answer 10

Male
Primary school age
Short stature
Limp
Knee pain on exercise
Stiff hip joint
Systemically well

Question 11

What is the aetiology of Perthes disease?

Answer 11

Pathologically avascular necrosis of hip

Possible relationship to coagulation tendency

Possible relationship to repeated minor trauma

Familial tendency

Classically low social status

Question 12

What are the 4 waldenstrom stages seen radiographically?

Answer 12

1) Initial stage
2) Fragmentation stage
3) Reossification stage
4) Healed stage

Question 13

How do you determine prognosis in Perthes disease?

presentation, etc

Answer 13

Presentation age:
-Younger do better

Proportion of head involved

Herring grade

Radiographic “head at risk signs”

Nearer the head is to round, the better the outlook

Question 14

What are the treatments for Perthes disease?

Answer 14

Maintain hip motion
Analgesia
Restrict painful activities

Consider osteotomy in selected groups of older children (>7)

Question 15

What percentage of perthes disease cases are bilateral?

Answer 15

10%

Question 16

What is the normal presentation of SUFE?

Answer 16

Teenage boys (9-14)
Left groin pain 3 months
Short, hip externally rotated
Painful to weight bear
Usually overweight
20% become bilateral

Question 17

What does SUFE stand for?

Answer 17

Slipped Upper Femoral Epiphysis

Question 18

What are the 3 ways to classify of SUFE?

Answer 18

Acute v chronic (3 weeks)

Magnitude of slip (angle or proportion

Stable vs unstable

• Unstable = unable to weight bear (poor prognosis)
• Stable = able to weight bear (good prognosis)

Question 19

How do you detect SUFE/ SCFE?

signs, symptoms, investigation

Answer 19

Pain in hip OR KNEE

Externally rotated posture and gait

Reduced internal rotation, especially in flexion

Plain x-rays
-best seen on lateral view

Question 20

What is the apthology of SUFE?

Answer 20

SUFE is essentially a type I Salter Harris growth plate injury due to repeated trauma on a background of mechanical and probably hormonal predisposing factors.

Conditions that may predispose to SUFE include:

• hypothyroidism
• hypopituitarism
• hyperparathyroidism

During growth, there is widening of the physeal plate which is particularly pronounced during a growth spurt. In addition, the axis of the physis alters during growth and moves from being horizontal, to being oblique. As the physis becomes more oblique, shear forces across the growth plate increase resulting in an increased risk of fracture and resultant slippage.

Question 21

What can the outcomes of SCFE be?

Answer 21

AVN

Chondrolysis

Deformity (short, ext rotated, limited flexion)

Early osteoarthritis

Possibility of slip on other side

Limb length discrepancy

Impingement

Question 22

What is the risk of AVN in SCFE?

Answer 22

Stable slips have a low risk of AVN

Unstable slips have a high risk of AVN

Question 23

What is a limp defined as?

Answer 23

Shorter stance phase (weightbearing) on the affected limb