Paediatric Hip Conditions

Question 1

what hip conditions can cause the ‘limping child’ presentations

Answer 1

DDH (developmental dysplasia of the hip)
reactive synovitis 
septic arthritis 
perthes 
SUFE

Question 2

when do you get DDH

Answer 2

birth- 2 years (and plus)

Question 3

when do you get perthes

Answer 3

4-8 ( 6 years peak)

Question 4

when do you get SUFE

Answer 4

10-16 years

Question 5

why does children acetabulum look like it has a hole in it

Answer 5

as just cartilage, ossifies over time

Question 6

why are x rays not as good for hip joints in kids

Answer 6

as a lot of femoral head will be cartilage- ultrasound better

Question 7

at what age does the greater trochanter show on an x ray

Answer 7

age 6

Question 8

what is developmental dysplasia of the hip

Answer 8

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

Question 9

describe the dysplasia in DDH

Answer 9

shallow or underdeveloped acetabulum

Question 10

what is capsular laxity more common in females

Answer 10

as they have more ligamentous laxity

Question 11

what is the most common orthopaedic disorder in newborns

Answer 11

DDH

Question 12

in who and which hip is DDH most common

Answer 12

in females in left hip (due to position in utero)

Question 13

can you get bilateral DDH

Answer 13

yes 20% of cases

Question 14

why is DDH seen in native american and laplanders but not africans

Answer 14

as papoose buts babys legs straight but baby sling puts hips in safety position- flexed and abducted

Question 15

what is the pathphysiology of DDH

Answer 15

maternal and fetal laxity, genetic laxity, intrauterine and postnatal malpositioning= initial instability

initial instability=dysplasia

dysplasia= gradual dislocation

Question 16

what happens in newborns when the femoral head isn’t properly positioned in the acetabulum

Answer 16

normal growth of femoral head and acetabulum not stimulated

Question 17

what are the risk factors for DDH

Answer 17

first borns 
breech postition 
family history 
6 x more common in females
oligohydramnios (not enough amniotic fluid)

Question 18

what is the presentation of DDH

Answer 18

abnormality on screening (early)

limping child (late):
- trendellenberg gait

pain in later life, secondary arthritic changes

Question 19

what should be done in clinical examination of DDH in new borns

Answer 19

inspection: leg lengths, restricted abduction, skin crease asymmetry

ortolani test- abducting the hips to try and relocate hip, fingers push femur forwards into acetabulum (already Out)

barlow test- pushing backwards to try to dislocate hip

Question 20

what is the treatment for early presentation DDH

Answer 20

pavlik harness- keeps hips abducted and flexed- 23 hours a day for up to 12 weeks

Question 21

what is the treatment for late presenting DDH

Answer 21

surgery

• closed reduction +/- tenotomies + spica
• open reduction +/- osteotomies + spica

Question 22

what criteria distinguishes between reactive are septic arthritis

Answer 22

kochers criteria; fever, refusal to bear weight, ESR, serum WBC, CRP

Question 23

what is the presentation of reactive arthritis

Answer 23

Hx of viral illness
limp and hip/groin pain 
may present with referred pain to knee 
hip lying flexed/ externally rotated 
pain at end range of hip movements 
systemically well. apyrexial

Question 24

how do you diagnose reactive synovitis

Answer 24

kochers, ultrasound (fluid in hip) +/- aspiration

Question 25

what is the treatment for reactive synovitis

Answer 25

self limiting analgesia/ NSAIDs repeat review/ admission if any concern

Question 26

why is septic arthritis a surgical emergency

Answer 26

high bacterial load that causes sepsis destruction of the joint due to proteolytic enzymes potential for osteonecrosis of the hip due to increased pressures

Question 27

what is the presentation of hip septic arthritis

Answer 27

``` short duration of symptoms unable to weight bear and hip/groin pain hip lying flexed/externally rotated severe hip pain on passive movement usually pyrexial ```

Question 28

how can septic arthritis get into the joint

Answer 28

direct inoculation (trauma/ surgery) haematogenous seeding extension from adjacent bone (osteomyelitis) can develop from contiguous spread from osteomyelitis

Question 29

septic arthritis can psread from highly vasular metaphysis to joints (common in neonates who have transphyseal vessels). what joints have intra articular metaphysis

Answer 29

hip, shoulder, elbow, ankle

Question 30

what is the most common causative organisms of septic arthritis of the hip

Answer 30

staph aureus

Question 31

how do you diagnose septic arthritis

Answer 31

blood test, blood cultures, kochers criteria, radiographs, ultrasound +/- aspiration

Question 32

what is the treatment for septic arthritis

Answer 32

open surgical washout | antibiotics

Question 33

what is perthes disease

Answer 33

avascular necrosis of the hip (idiopathic)

Question 34

who gets perthes

Answer 34

4-8 year olds, more common in boys, higher in lower socioeconomic class

Question 35

what are the risk factors for perthes

Answer 35

positive family history, low birth weight, second hand smoke, asian, inuit and central american decent (abnormal clotting factors, repeated trauma. mechanical overload)

Question 36

what is the pathophysiology of perthes disease

Answer 36

osteonecrosis occurs secondary to disruption of blood supply to femoral head followed by revascularisation with subsequent resorption and later collapse creeping substitution pathway for remodelling after collapse

Question 37

what are the stages of perthes disease

Answer 37

initial fragmentation reossification remodelling

Question 38

what factors can improve prognosis of perthes

Answer 38

younger age at presentation | preservation of a round femoral head

Question 39

how does perthes present

Answer 39

``` gradual onset of painless limp sometimes intermittent groin pain hip stiffness (internal rotation and abduction) limp- trendellenberg, antalgic ```

Question 40

how do you diagnose perthes

Answer 40

radiographs, MRI

Question 41

what is the treatment for perthes

Answer 41

keep femoral head round whilst the process self terminates restrict weight bearing physio to maintain ROM surgery in severe disease/ deformity

Question 42

what is SUFE

Answer 42

slipped upper femoral epiphysis affects proximal femoral physis- leads to slippage of the metaphysis relative to the epiphysis

Question 43

what are the risk factors for SUFE

Answer 43

``` males obesity endocrine disorders -growth hormone deficiency -panhypopituritarism -hypothyroidism growth spurts ```

Question 44

how does SUFE present

Answer 44

``` groin pain (or knee/ thigh) limp -externally rotated foot -antalgic obligatory external rotation on hip rotation ```

Question 45

how do you diagnose SUFE

Answer 45

radiographs, MRI

Question 46

what is the treatment of SUFE

Answer 46

surgery- percutaneous pinning of the hip