The Limping Child Flashcards
What age group does congenital dislocation tend to affect? What is the incidence?
Birth; 2 in 1000
5-20 per 1000 hips are lax at birth
What age group does osteomyelitis tend to affect? What is the incidence?
0-5 years; 1 in 1000
What age group does Perthe’s disease tend to affect? What is the incidence?
5-10 years; 1 in 10,000
What age group do slipped femoral epiphyses tend to affect? What is the incidence?
10-15 years; 1 in 100,000
What age group does avascular necrosis tend to affect? What is the incidence?
Adults; 1 in 100,000
What is the commonest cause of the painful hip in a young child?
‘Irritable hip’ - a transient synovitis secondary to a viral illness
This is a diagnosis of exclusion
What is ‘irritable hip’?
A transient synovitis secondary to a viral illness that presents as a painful hip in young children. It is a Dx of exclusion
True or false: most dislocated or dislocatable hips become stable within the first few weeks of life
True - considered to be due to physiological laxity of the joint capsule
Why is congenital dislocation the hip considered a misnomer?
- Not always a dislocation
- Not always present at birth
Perhaps better classified as developmental dysplasia of the hip (DDH)
What is CDH/DDH?
‘Congenital dislocation’ or ‘developmental dysplasia’ of the hip
- A congenitally determined deformation of the hip in which the head of the femur is or may be completely or partially displaced from the acetabulum
True or false: in DDH, females are affected more than males
True
What proportion of DDH cases are bilateral?
1/3
What is the aetiology of DDH?
Unknown
- Familial tendency
- Position of foetus in uterus, i.e. decreased intrauterine space
Higher incidence if
a. Joint laxity/shallow acetabulum in 1st order relatives
b. Breech presentation
c. First born
d. Oligohydramnios
e. North American Indian - wrap babies tightly with hips extended and legs together
List 4 risk factors for DDH
- Joint laxity/shallow acetabulum in 1st order relatives
- Breech presentation
- First born
- Oligohydramnios
- North American Indian
When is the best time to screen for DDH?
At birth, during routine postnatal examination
What warning signs may be noted on examination for DDH?
- Syndromic facies
- Scoliosis
- Asymmetry of gluteal skin folds (in newborn) or inguinal skin folds (3-4 month old)
- Ortolani’s test +ve
- Barlow test +ve
What does Ortolani’s test detect? Describe it
Detects a dislocated hip
- Hip and knees flexed to 90 degrees
- Thighs grasped in each hand
- Thumb over inner thigh and fingers rested over greater trochanters
- Hips abducted gently
Normal: 90 degrees easily
Resistance if dislocated
+ve test: gentle pressure applied to greater trochanters by fingers; click felt as hip relocates
What does Barlow’s test detect? Describe it
Detects a dislocatable hip
Modified Ortolani’s test:
- During abduction phase, firm pressure applied in line of femur so that a lax hip dislocates posteriorly
Following examination of a newborn infant you suspect developmental displasia of the hip. Barlow’s test is positive. How do you proceed?
Ultrasound scan - Shape of cartilaginous socket - Position of head of femur X-rays - not helpful - Femoral head does not calcify until 10 weeks
True or false: X-rays are needed to confirm the diagnosis of a suspected developmental dysplasia of the hip
False - femoral head does not calcify until 10 weeks. US indicated
What are the principles of treatment for DDH?
Reduction - closed or open methods - to hold head of femur in place until ace tabular rim is sufficiently developed
How is closed reduction achieved in the newborn?
- Double nappies to abduct hips
- Reassessment with US after 2-3 weeks - Pavlik harness
- Few months, regular US - Hip spica cast
- Arthrogram under GA
+/- Tenotomy of abductors
- Look for concentricity of hip
When should an open reduction be carried out for DDH?
If hip cannot be easily concentrically reduced using closed methods. Usually carried out at a later stage (nearer 1 year old) - hip left untreated in interim
True or false: examination of DDH under anaesthesia is usually an elective procedure
True - higher risks in babies; experienced paediatric anaesthetist needed
