Paediatric Hip Problems

Question 1

what is developmental dysplasia of hip (DDH)

Answer 1

a disorder of abnormal development resulting in dysplasia and possible subluxation or dislocation of hip secondary to capsular laxity and mechanical factors

Question 2

what is prevalence of DDH

Answer 2

5 in 1000 babies

girls account for 80% of cases

Question 3

what hip is DDH more common in

Answer 3

left hip (due to intrauterine position) but 20% of cases is bilateral

Question 4

what are risk factors for DDH

Answer 4

family history of DDH
breech presentation 
first born babies 
downs syndrome 
other congenital disorders (talipes, arthrogryposis)

Question 5

what are symptoms of DDH

Answer 5

shortening
asymmetric grin / thigh skin creases
clink or clunk of ortolani or barlow manoeuvres (early)
limping child (late)

Question 6

what is ortolani manoeuvre

Answer 6

reducing a dislocated hip with abduction and anterior displacement

Question 7

what is barlows manoevure

Answer 7

dislocatable hip with flexion and posterior displacement

Question 8

how is DDH diagnosed

Answer 8

positive ortolani or barlow test requires further evaluation with US
Xray cannot be used until 4-6 months

Question 9

what is treatment for mild DDH

Answer 9

closely observed with serial examination and US to ensure hip remains reduced

Question 10

what is treatment for dislocated or persistently unstable hips DDH

Answer 10

reduced and held in pavlik harness which keeps hips in comfortable flexion an abduction
used full time for 6 weeks and PT for another 6 weeks

Question 11

what is treatment for DDH with persistent dislocation over 18 months or presenting late

Answer 11

closed reduction +/- tenotomies + spica cast

open reduction + osteotomies + spica cast

Question 12

what is complication of persistent or undiagnosed DDH

Answer 12

acetabulum very shallow
more severe = false acetabulum occurs proximal to original one with shortened lower limb
severe arthritis due to reduced contact area

Question 13

what is transient synovitis of hip (reactive synovitis)

Answer 13

self limiting inflammation of the synovium of the hip

most common cause of hip pain in childhood

Question 14

what causes transient synovitis of hip

Answer 14

commonly occurs shortly after URTI although sometimes no cause found

Question 15

who is most commonly affected by transient synovitis of hip

Answer 15

age 2-10 years and boys more commonly affected than girl

Question 16

what are symptoms of transient synovitis of hip

Answer 16

limp or reluctance to bear weight
maybe referred pain to knee
range of motion restricted (but not as much as septic arthritis)
hip lying flexed / externally rotated
may have low grade fever but not systemically unwell or septic

Question 17

how is transient synovitis of hip diagnosed

Answer 17

radiographs can exclude perthes disease

normal CRP and clinical picture more suggestive of transient synovitis may exclude septic arthritis

Question 18

what criteria is used to distinguish between transient synovitis of hip and septic arthritis of hip

Answer 18

kochers criteria

Question 19

how is transient synovitis of hip treated

Answer 19

once more serious cause excluded:
self limiting - resolves in few weeks
NSAIDs and rest

Question 20

what is perthes disease (aka legg-calve-perthes disease)

Answer 20

avascular necrosis / compression osteochondritis of hip

the femoral head transiently loses blood supply resulting in necrosis with subsequent abnormal growth

Question 21

who is the incidence of perthes disease higher in

Answer 21

ages 4-9 and more common in boys (5:1) esp active boys of short stature
higher in lower socioeconomic classes

Question 22

what are risk factors of perthes disease

Answer 22

family history
low birth weight
second hand smoke
Asian, inuit and central european descent

Question 23

what are the symptoms of perthes disease

Answer 23

pain and a limp (sometimes groin or knee pain)
mostly unilateral
loss of internal rotation followed by loss of abduction
later, there will be + trendellenburg test from gluteal weakness

Question 24

how is perthes disease diagnosed

Answer 24

radiographs and MRI

Question 25

how is perthes disease treated

Answer 25

no specific tx other than regular xray observation and avoidance of physical activity

Question 26

approx 50% of cases of perthes disease do well, what happens when they dont

Answer 26

some cases = femoral head becomes aspherical, flattened and widened causing alternation of abductor muscle resulting in weakness (trendelenburg +ve)
occasionally = femoral head may sublux requiring osteotomy of femur or acetabulum

Question 27

by which classification determines risk of arthritis in perthes disease

Answer 27

stulberg 
spherical congruity (I&II) - no arthritis 
aspherical congruity (III&IV) - mild arthritis mid-late adult 
aspherical incongruity (V) - severe arthritis before 50

Question 28

what is slipped upper femoral epiphysis (SUFE) and who does it effect

Answer 28

condition which mainly affects overweight pre-pubertal boys where femoral head epiphysis slips inferiorly in relation to femoral neck

Question 29

why does the femoral head slip in SUFE

Answer 29

the growth plate (physis) not strong enough to support body weight and the epiphysis slips due to strain

Question 30

what are symptoms of SUFE

Answer 30

pain and limp
externally rotated foot
pain may be felt in groin or KNEE (obturator nerve)
loss of internal rotation is predominant clinical sign

Question 31

how is SUFE diagnosed

Answer 31

xray changes may be subtle and lateral view must be obtained to detect mild slip
MRI

Question 32

what is the treatment of SUFE

Answer 32

urgent surgery to pin the femoral head to prevent further slippage = percutaneous pinning of hip +/- pinning of other side or +/- open reduction of very severe slip

Question 33

what is the prognosis of SUFE depending on the degree of slip

Answer 33

mild slips = favourable
acute slips = gentile manipulation may be attempted but this risks AVN
chronic severe slips = may require osteotomy
some cases may require hip replacement in adolescence or early adulthood