Peadiatric Hip Conditions Flashcards
when does DDH tend to present?
birth - 2 years
when does perthes disease tend to present?
4-8 years
when does SUFE tend to present?
10-16 years
how does the acetabulum develop>
triradiate cartilage in the middle ossifies over time
- cartilage composed of ischium, ilium and pubis
why is X ray not that useful in very young children? what is used instead?
femoral head has not yet ossified so wont be seen on X ray
US is better
H line on X ray?
horizontal line across the 2 triradiate cartilages - shows symmetry
what other lines can show positioning of hip on X ray?
2 perpendicular perkin lines - intersect the H line - upper femoral epiphysis should be mainly be in the lower left corner of the intersecting lines
what is DDH?
developmental dysplasia of the hip
developmental disorder resulting in dysplasia and possible subluxation/dislocation of the hip secondary to capsular laxity and mechanical factors
describe the spectrum of DDH
just dysplasia with shallow/underdeveloped acetabulum
subluxation
dislocation
where does DDH most commonly occur?
left hip in females (due to they way the baby lies in utero)
but can be bilateral
what demographics is DDH more/less common in?
more common in native americans and Laplanders
less common in African patients
- due to the way baby is carried after birth
describe the pathophysiology of DDH?
initial instability caused by maternal and fetal laxity, genetic laxity and intrauterine and postnatal malpositioning
describe the pathoanatomy of DDH
initial instability leads to dysplasia,dysplasia leads to gradual dislocation
how does DDH differ to a normally developing hip?
normal = correctly positioned femoral head stimulates normal head and acetabular growth
absent in DDH where hip never was or becomes subluxed/dislocated
what are the risk factors for DDH?
first borns female breech presentation family history oligohydramnios
how does DDH present?
abnormality on screening
limping - trandellenberg gait
pain later in life
why do DDH patients get a trandellenberg gait?
short lever arm means abductors need to work harder
how is DDH diagnosed?
clinical exam - leg lengths, restricted abduction, skin creases
US
radiographs
what 2 clinical tests can indicate DDH?
ortolani - can you reduce the dislocated hip back in?
Barlows - can you dislocate the hip?
how is early DDH treated?
Pavlik harness - pute femoral head into position of safety (abduction and flexion)
night time splinting for a few weeks afterwards
how is Pavlik harness used?
worn 23 hrs a day for up to 12 weeks until US is normal
how is late DDH treated?
surgery
- closed reduction +/- tendonotomies + spica (cast)
- open reduction + osteotomies + spica (cast)
hip arthrogram to assess congruency during treatment
what is reactive synovitis?
inflammation of the synovium, often secondary to a viral illness
how does reactive arthritis present?
history of viral illness limp with hip/groin pain can have only referred pain to the knee lying with hip flexed/externally rotated pain at end range of hip movement usually generally well
how is reactive synovitis diagnosed?
kochers criteria
US +/- aspiration
what is kochers criteria?
distinguishes between septic arthritis and reactive arthritis
- higher score = more chance of it being septic arthritis
how is reactive synovitis treated?
self limiting
analgesia/NSAIDs
what is septic arthritis of the hip?
intra-articular infection of the hip joint
why is septic arthritis a surgical emergency?
high bacteria load causing sepsis
destruction of joint due to proteolytic enzymes
potential for osteonecrosis of the hip due to increased pressure
how does septic arthritis of the hip present?
sudden onset unable to weight bear due to pain hip lying flexed/externally rotated severe hip pain on passive movement usually pyrexial but can be haemodynamically stable
through what 5 mechanisms can septic arthritis occur?
direct inoculation
hematogenous seeding
extension from adjacent bone (osteomyelitis)
continuous spread of osteomyelitis
can often spread from highly vascular metaphysis
what are the most common causative organisms in septic arthritis?
neonates - strep
infant - adults = staph aureus
IV drug user = suspect pseudomonas and atypical
how is septic arthritis treated?
blood tests blood cultures kochers criteria radiographs (to rule out) US +/- aspiration
how is septic arthritis treated?
open surgical washout (with samples)
antibiotics for 6 weeks
what is perthes disease?
avascular necrosis of the hip
risk factors for perthes?
male 4-8 year olds lower socioeconomic class family history low birth weight second hand smoke Asian, inuit, central europe
is perthes unilateral or bilateral?
usually unilateral
describe the pathophysiology of perthes
osteonecrosis occurs secondary to disruption of blood supply to femoral head
followed by revascularisation with subsequent resorption and later collapse
creeping substitution provides pathway for remodelling after collapse
what are some proposed mechanisms for perthes development?
possible association with abnormal clotting factors
repeated subclinical trauma and mechanical overload lead to bone collapse and repair
what are the stages of perthes disease?
initial
fragmentation
reossification
remodelling
what determines prognosis in perthes?
age
- younger = better
how does perthes present?
gradual painless limp
sometimes intermittent groin/thigh/knee pain
hip stiffness
limp (trendelenberg gait)
how is perthes diagnosed?
radiograph
MRI
how is perthes treated?
aim to keep femoral head round whilst the process self terminates
restrict weight bearing
maintain ROM with physio
is surgery ever used in perthes?
occasionally
young patients with severe disease/deformity
older patients with secondary osteoarthritis
what is SUFE?
slipped upper femoral epiphysis
condition affecting the proximal femoral physis that leads to slippage of the metaphysis relative to the epiphysis
what are the risk factors for SUFE?
male
obesity
endocrine disorders
associated with a period of rapid growth
how does SUFE present?
variable length of development groin pain (or knee/thigh) limp obligatory external rotation on hip flexion
how is SUFE diagnosed?
radiographs
MRI
how is SUFE treated?
surgery
- pinning of the hip
- +/- pinning of the other side +/- open reduction if very severe
