Level 2 - MSK Flashcards
What is developmental dysplasia of hip?
- A spectrum of severity ranging from stable acetabular dysplasia to established hip dislocation
Epidemiology of DDH?
- Affects 1-3% of newborns
- Females 6:1 males
- Left hip most commonly affected
- Bilateral in 1/3
Risk factors for DDH?
o Sibling with DDH
o Vaginal deliveries, breech delivery
o Oligohydramnios
o Multiple pregnancy, prematurity
o Cerebral palsy
Describe disease progression in DDH?
o Capsular laxity + shallow acetabulum
o Instability/subluxation/dislocation
o Muscle contracture
o Progressive acetabular dysplasia with a fibro-fatty substance filling the acetabulum (pulvinar); femoral head becomes hypoplastic
What would parents notice in DDH? What is Galeazzi’s sign?
- Notice delayed walking, painless limp, limited abduction, increased falls
- Galeazzi sign – hips and knees flexed 90o, unilateral femoral shortening may signify hip dislocation
What screening tool is performed to prevent missing DDH? When should furthe testing be performed?
o NIPE baby check at <48 hours and 6-8 weeks
o If high risk, baby should have USS at 2-4 weeks
o Barlow’s manoeuvre
Screen for a dislocatable hip
Gentle backward pressure to the head of each femur in turn
A subluxable hip is suspected on palpable displacement
o Ortolani’s test
Screens for dislocated hip
Abduction and lateral rotation
Move a posteriorly dislocated femoral head forwards into the acetabulum
Palpable movement suggests that the hip is dislocated or subluxed, but reducible
What imaging should be done in DDH and when?
o Dynamic USS (<4.5 months)
o Pelvic X-rays (>4.5 months) Shallow acetabulum with incd acetabular index and hypoplastic femoral head
Prognosis of DDH?
- Most unstable hips stabilise spontaneously by 2-6 weeks, any hip that remains dislocatable or pathologically unstable requires prompt treatment
What is the management of DDH in <6 months?
o Long-term splinting in flexion-abduction (Pavlik harness)
What is the management of DDH in 6-18 months?
o Exam-under-anaesthetic and open/closed reduction followed by immobilisation in spica hip (casting)
What is the management of DDH in >18 months?
o Open reduction with corrective femoral/pelvic osteotomies to maintain stability
Complications in DDH?
- Re-dislocation, stiffness, blood loss, avascular necrosis
- Premature degenerative joint disease
- Lower back pain
What is transient synovitis?
- Hip pain, swelling of joint often following a viral infection (recent URTI, gastric illness)
How common is transient synovitis?
- Most common cause of acute hip pain in 4-10 year olds
Risk factors for transient synovitis?
- Boys twice as likely
- HLABR7 in Reiter’s syndrome