SCFE

Question 1

RIsk factors for SCFE

Answer 1

• obesity
• femoral retroversion
• prior radiation therapy to the femoral head

Question 2

Zone of SCFE injury:

Answer 2

hypertrophic zone, weakness in the perichondral ring

Question 3

where does the neck displace?

Answer 3

anteriorly, superiorly

retroverts the epiphysis

Question 4

associated endocrine disorders?

Answer 4

• hypothyroidism

- renal osteodystrophy

Question 5

Loder classification

Answer 5

stable (can bear weight)

unstable (can’t bear weight… risk of osteonecrosis is ~50%)

Question 6

Southwick’s angle classification

Answer 6

mild <30 deg
moderate 30-50 deg
severe >50 deg

Question 7

Grading a SCFE:

Answer 7

I 0-33%
II 34-50%
III >50%

Question 8

should you pin contralateral side?

Answer 8

yes if:
- obese male
- endocrine disorder
slip in a child <10 years of age

Question 9

compolications of SCFE

Answer 9

• AVN femoral head 5% (50% in high grade slips
• chondrolysis from the screw
• slip progression (1-2%)

Question 10

Age related risk for contralateral slip?

Answer 10

girls <10

boys <12

Question 11

Screw thread relationship to failure?

Answer 11

16mm threads have higher frequency of femoral neck failure compared with 32mm or fully threaded screws

Question 12

factors associated with AVN in SCFE:

Answer 12

unstable slip

• overreduction of slip
• attempted reduction of chronic slip
• pins in superolateral quadrant
• femoral neck osteotomy