Peadiatric Hip Conditions

Question 1

when does DDH tend to present?

Answer 1

birth - 2 years

Question 2

when does perthes disease tend to present?

Answer 2

4-8 years

Question 3

when does SUFE tend to present?

Answer 3

10-16 years

Question 4

how does the acetabulum develop>

Answer 4

triradiate cartilage in the middle ossifies over time

- cartilage composed of ischium, ilium and pubis

Question 5

why is X ray not that useful in very young children? what is used instead?

Answer 5

femoral head has not yet ossified so wont be seen on X ray

US is better

Question 6

H line on X ray?

Answer 6

horizontal line across the 2 triradiate cartilages - shows symmetry

Question 7

what other lines can show positioning of hip on X ray?

Answer 7

2 perpendicular perkin lines - intersect the H line - upper femoral epiphysis should be mainly be in the lower left corner of the intersecting lines

Question 8

what is DDH?

Answer 8

developmental dysplasia of the hip
developmental disorder resulting in dysplasia and possible subluxation/dislocation of the hip secondary to capsular laxity and mechanical factors

Question 9

describe the spectrum of DDH

Answer 9

just dysplasia with shallow/underdeveloped acetabulum
subluxation
dislocation

Question 10

where does DDH most commonly occur?

Answer 10

left hip in females (due to they way the baby lies in utero)

but can be bilateral

Question 11

what demographics is DDH more/less common in?

Answer 11

more common in native americans and Laplanders
less common in African patients
- due to the way baby is carried after birth

Question 12

describe the pathophysiology of DDH?

Answer 12

initial instability caused by maternal and fetal laxity, genetic laxity and intrauterine and postnatal malpositioning

Question 13

describe the pathoanatomy of DDH

Answer 13

initial instability leads to dysplasia,dysplasia leads to gradual dislocation

Question 14

how does DDH differ to a normally developing hip?

Answer 14

normal = correctly positioned femoral head stimulates normal head and acetabular growth
absent in DDH where hip never was or becomes subluxed/dislocated

Question 15

what are the risk factors for DDH?

Answer 15

first borns
female
breech presentation
family history
oligohydramnios

Question 16

how does DDH present?

Answer 16

abnormality on screening
limping - trandellenberg gait
pain later in life

Question 17

why do DDH patients get a trandellenberg gait?

Answer 17

short lever arm means abductors need to work harder

Question 18

how is DDH diagnosed?

Answer 18

clinical exam - leg lengths, restricted abduction, skin creases
US
radiographs

Question 19

what 2 clinical tests can indicate DDH?

Answer 19

ortolani - can you reduce the dislocated hip back in?

Barlows - can you dislocate the hip?

Question 20

how is early DDH treated?

Answer 20

Pavlik harness - pute femoral head into position of safety (abduction and flexion)
night time splinting for a few weeks afterwards

Question 21

how is Pavlik harness used?

Answer 21

worn 23 hrs a day for up to 12 weeks until US is normal

Question 22

how is late DDH treated?

Answer 22

surgery
- closed reduction +/- tendonotomies + spica (cast)
- open reduction + osteotomies + spica (cast)
hip arthrogram to assess congruency during treatment

Question 23

what is reactive synovitis?

Answer 23

inflammation of the synovium, often secondary to a viral illness

Question 24

how does reactive arthritis present?

Answer 24

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

Question 25

how is reactive synovitis diagnosed?

Answer 25

kochers criteria | US +/- aspiration

Question 26

what is kochers criteria?

Answer 26

distinguishes between septic arthritis and reactive arthritis - higher score = more chance of it being septic arthritis

Question 27

how is reactive synovitis treated?

Answer 27

self limiting | analgesia/NSAIDs

Question 28

what is septic arthritis of the hip?

Answer 28

intra-articular infection of the hip joint

Question 29

why is septic arthritis a surgical emergency?

Answer 29

high bacteria load causing sepsis destruction of joint due to proteolytic enzymes potential for osteonecrosis of the hip due to increased pressure

Question 30

how does septic arthritis of the hip present?

Answer 30

``` 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 ```

Question 31

through what 5 mechanisms can septic arthritis occur?

Answer 31

direct inoculation hematogenous seeding extension from adjacent bone (osteomyelitis) continuous spread of osteomyelitis can often spread from highly vascular metaphysis

Question 32

what are the most common causative organisms in septic arthritis?

Answer 32

neonates - strep infant - adults = staph aureus IV drug user = suspect pseudomonas and atypical

Question 33

how is septic arthritis treated?

Answer 33

``` blood tests blood cultures kochers criteria radiographs (to rule out) US +/- aspiration ```

Question 34

how is septic arthritis treated?

Answer 34

open surgical washout (with samples) | antibiotics for 6 weeks

Question 35

what is perthes disease?

Answer 35

avascular necrosis of the hip

Question 36

risk factors for perthes?

Answer 36

``` male 4-8 year olds lower socioeconomic class family history low birth weight second hand smoke Asian, inuit, central europe ```

Question 37

is perthes unilateral or bilateral?

Answer 37

usually unilateral

Question 38

describe the pathophysiology of perthes

Answer 38

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

Question 39

what are some proposed mechanisms for perthes development?

Answer 39

possible association with abnormal clotting factors | repeated subclinical trauma and mechanical overload lead to bone collapse and repair

Question 40

what are the stages of perthes disease?

Answer 40

initial fragmentation reossification remodelling

Question 41

what determines prognosis in perthes?

Answer 41

age | - younger = better

Question 42

how does perthes present?

Answer 42

gradual painless limp sometimes intermittent groin/thigh/knee pain hip stiffness limp (trendelenberg gait)

Question 43

how is perthes diagnosed?

Answer 43

radiograph | MRI

Question 44

how is perthes treated?

Answer 44

aim to keep femoral head round whilst the process self terminates restrict weight bearing maintain ROM with physio

Question 45

is surgery ever used in perthes?

Answer 45

occasionally young patients with severe disease/deformity older patients with secondary osteoarthritis

Question 46

what is SUFE?

Answer 46

slipped upper femoral epiphysis | condition affecting the proximal femoral physis that leads to slippage of the metaphysis relative to the epiphysis

Question 47

what are the risk factors for SUFE?

Answer 47

male obesity endocrine disorders associated with a period of rapid growth

Question 48

how does SUFE present?

Answer 48

``` variable length of development groin pain (or knee/thigh) limp obligatory external rotation on hip flexion ```

Question 49

how is SUFE diagnosed?

Answer 49

radiographs | MRI

Question 50

how is SUFE treated?

Answer 50

surgery - pinning of the hip - +/- pinning of the other side +/- open reduction if very severe