Pedi Ortho

Question 1

Risk factors for DDH

Answer 1

female (6:1), firstborn, breech, family history, oligohydramnios

Question 2

In DDH, where is the typical acetabular deficiency?

Answer 2

Anterior or anterolateral

In spastic CP, it is posterior-superior

Question 3

Describe the ‘lines’ on a pediatric AP pelvis XR

Answer 3

Hilgeneiner’s: horizontal line through both triraidates; femoral head should be lateral
Perkin’s: perpendicular to Hilg, at the most lateral aspect of the tab; femoral head should be medial
Shenton’s: arc along the inferior femoral neck and superior obturator foramen

Question 4

What is the pathoantatomic mechanism of medial epicondylar fractures?

Answer 4

Avulsion of the medial epicondyle from pull of the flexor/supinator mass and valgus stress

Question 5

Order of appearance for ossification centers in the elbow?

Answer 5

CRMTOL
Capitellum 1yr
Radial head 3yr
Medial epicondyle 5yr
Trochlea 7yr
Olecranon 9yr
Lateral epicondyle 11yr

Question 6

Order of fusion for pediatric elbow?

Answer 6

CTL R OM
CTL 12-14
R 14-16
OM 15-18 (medial epicondyle last to fuse)

Question 7

What is the most common nerve injury in extension type supracondylar fractures? In flexion type fractures?

Answer 7

Extension type: AIN palsy, second is radial

Flexion type: ulnar nerve palsy

Question 8

Describe the Gartland classification.

Answer 8

Supracondylar humerus fractures
Type 1: non-displaced
Type 2: posterior cortex/periosteal hinge with disruption of anterior humeral line
Type 3: Completely displaced
Type 4: unstable in flexion and extension, intraop diagnosis only

Question 9

What is the natural history of Kohler’s disease?

Answer 9

Resolution of symptoms in 1-3 years.