PEDIATRIC Section 13: MSK (Hip Dysplasia)

Question 1

Developmental Dysplasia of the Hip (DDH)

Answer 1

asymmetric skin or gluteal folds
leg length discrepancy
palpable clunk
delayed ambulation.

Question 2

Developmental Dysplasia of the Hip (DDH)

Answer 2

This is seen more commonly in females, children bom breech, and oligohydramnios.

Question 3

Developmental Dysplasia of the Hip (DDH) on USD

Answer 3

On ultrasound the alpha angle, should be more than 60 degrees.

Anything less than that and your cup is not deep enough to hold your ball.

“AlphaAngleistheAlphaMale”- and therefore the bigger of the two angles.

Question 4

Developmental Dysplasia of the Hip (DDH) on CXR

Answer 4

acetabular angle, which is the complimentary angle (and therefore should be less than 30).

The acetabular angle should decrease from 30 degrees at birth to 22 degrees at age 1. DDH is the classic cause of an increased angle, but neuromuscular disorder can also increase it.

Question 5

Where the the position of the femoral epiphysis (or where it will be) should be

Answer 5

Below the Hilgenreiner’s line
Medial to Perkin’s line
Shenton’s line “S” Shoud be continusous

Question 6

This is a congenital zebra, which ranges from absent proximal femur to hypoplastic proximal femur.

Answer 6

Proximal Focal Femoral Deficiency:

Question 7

“weird fucked up looking tiny Frankenstein leg. “

+ varus devormity

Answer 7

Proximal Focal Femoral Deficiency:

Question 8

This is described as a mimic of DDH

Answer 8

Proximal Focal Femoral Deficiency

Question 9

Proximal Focal Femoral Deficiency vs DDH (Developmental Dysplasia of the HIP)

Answer 9

This is described as a mimic of DDH,
but DDH will have normal femur leg length (not a fucked up looking tiny Frankenstein leg).

Question 10

fat African American adolescent (age 12-15) with hip pain.

This is a type 1 Salter Harris, through the proximal femoral physis. What makes this unique is that unlike most SH Is, this guy has a bad prognosis if not fixed.

Answer 10

Slipped Capital Femoral Epiphysis (SCFE)

Question 11

wht View on Xray should be done after suspecting Slipped Capital Femoral Epiphysis (SCFE)

Answer 11

Drawn along the edge of the femur and should normally intersect with lateral superior femoral epiphysis. This line is used to evaluate for SCFE (Slipped Capital Femoral Epiphysis)

Question 12

“Klein’s Line”

Answer 12

When the line doesn’t cross the lateral epiphysis think SCFE.

Question 13

View on Xray more sensitive when measurement “Klein’s Line”

Answer 13

Frog leg

Question 14

This is AVN of the proximal femoral epiphysis.

Answer 14

Legg-Calve-Perthes

Question 15

Where is Legg-Calve-Perthes seen?

Answer 15

Boys (4:1)
5-8 y.o
Bilateral 10% of the time

Question 16

Subchondral lucency (crescent sign) in the femoral epyhysis seen on frog leg

Answer 16

Legg-Calve-Perthes

Question 17

Answer 17

Legg-Calve-Perthes

flat collapsed femoral head

Question 18

This is serious business , and considered the most urgent cause of painful
hip in a child.

Answer 18

Septic arthritis

Question 19

What should prompt USD and Joint tap in a child with painflul hip?

Answer 19

Wide joint spaces (Lateral displacement of the femoral head)

Question 20

This is a sterile (reactive) hip effusion that occurs in the setting of
a systemic illness (usually viral URI or GI).

Answer 20

Transient Synovitis

Question 21

Mot common hip disorder in growing child (peak age is around 5)

Answer 21

Transient Synovitis

Question 22

What is the Kocher Criteria?

Answer 22

4 parts:
Ferver
Inability to walk
Elevated ESR (or CRP)
WBC > 12k

If 3/4 + = Septic
IF (-) CRP + the kid can bear weight = NOT septic

Question 23

What is the strongest independent risk factor for septic arthritis?

Answer 23

CRP

Question 24

Work up fo Transient Synovitis vs Septic Arthritis?

Answer 24

Medial joint widening on Xray + Effusion on USD + (>2) Kocher criteria score + MRI when hip aspiration hasn’t been performed