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
What is the commonest open reduction procedure used to treat DDH?
Derotation varus osteotomy of the femur
- Leg rotated to a position where head has maximum covering of acetabulum
- Femur then sawed just below trochanters and shaft allowed to rotate back to neutral position
- Two ends fixed using a Coventry screw plate
- Plaster spica for a few weeks
- Clinical and radiological f/u once toddler is walking to assess ace tabular development
What is a Salter osteotomy and when is it indicated?
Pelvic osteotomy to reposition acetabulum, to better accomodate femoral head.
Performed in patients with DDH if outcome of a derotation varus osteotomy is not satisfactory. Delayed until child is 2 years of age.
At what age can X-rays be used to assess the acetabulum?
After about 6 months
If CDH is missed at the time of birth, when is the diagnosis usually made?
At 12-18 months when child begins to walk with abnormal gait
What are the late signs of CDH in a 12-18 month year old?
- Abnormal gait
- Limb shortening
- External rotation of foot
- Asymmetrical skin creases
- +ve Trendelenburg test
True or false: closed reduction is usually unsuccessful in children who are diagnosed with CDH late
True - lip of labrum or loose capsule impedes reduction
True or false: with bilateral CDH, deformities and abnormalities of gait are less noticeable
True - because they are symmetrical
True or false: most surgeons would not operate on patients with bilateral CDH above the age of 6 years
True - if one side fails, there is a risk of converting them to a unilateral asymmetrical deformity
What is Perthe’s disease and in which patients is it usually seen?
A type of osteochondritis - AVN of the femoral head.
How does Perthe’s disease typically present?
Males 4-10 years Limp Pain - Initially, then painless - Groin, radiating to knee
What is the differential for hip pain in children under 10?
- Perthe’s disease
- Infection
- Transient synovitis
What are the radiological features of Perthe’s disease?
X-rays:
- Usually normal
- Early: increased density at epiphysis
- Later - epiphysis flattens and fragments
Bone scan:
- Useful in early stages
What is the treatment for Perthe’s disease?
- Bed rest until pain subsides
- Dead bone can revascularise and remodel - Operative Rx to contain head in acetabulum (depends on X-rays)
What is the main long-term complication of Perthe’s disease?
Osteoarthritis of the hip
Why is it important to diagnose Perthe’s disease early?
Dx after age 10 associated with very high risk of developing OA
What does SCFE stand for? What is it?
Slipped capital femoral epiphysis - an uncommon condition usually found in children of pubertal age. Epiphysis slips posteriorly either as an acute (20%) or chronic event (60%), or a combination of the two (20%)
Which two groups does SCFE tend to affect?
- Fat and sexually underdeveloped
- Tall and thin
Boys more than girls
What is the aetiology of SCFE?
- Endocrine factors
- Fat children have higher incidence
- Hormonal imbalance at time of growth spurt - Mechanical factors
How does an acute slip in SCFE usually present?
- Pain - groin or referred to knee
- Leg shortening
- External rotation
- All movements initially painful
What is the treatment for SCFE?
Acute slip - usually surgical ORIF
Chronic
- Reduction not advised due to risk of AVN
- In situ pinning to prevent further slippage
What are the main risks of surgery for SCFE?
- AVN in chronic SCFE
2. Chondrolysis - higher risk if guide-wire or pin penetrates articular cartilage
What are the 3 main long term complications of hip disorders?
- Disability
- Deformity
- OA
When is irritable hip typically diagnosed?
Dx of exclusion in children aged 1-10 years that present with a limp and pain in the hip
What is thought to be the cause of irritable hip?
Viral synovitis - often preceding URTI
What is the most important diagnosis to rule out in a child presenting with a limp and pain in the hip? How is this done?
Septic arthritis
- FBC, CRP, ESR
- US may be helpful
- Urgent aspiration/analysis
How is irritable hip treated and what is the prognosis?
Usually settles with rest and analgesia over 2-3 days
