Week 3 - Normal lower limb development and common variations

Question 1

how does knee alignment change throughout childhood?

Answer 1

birth = varus
14 months = normal
3 = valgus (10-15 degrees)
7-9 = normal slight valgus (6 degrees)

Question 2

is varum or valgus always abnormal?

Answer 2

no

minor varum or valgus can be familial

Question 3

what is the definition of pathological varus/valgus?

Answer 3

where alignment is considered outside the normal range of +/- 6 degrees from mean age value

Question 4

by what age do most varum/valgus deformities resolve? what happens if they don’t?

Answer 4

age 10

consider surgery

Question 5

what can cause a varum/valgus deformity?

Answer 5

many are idiopathic
some are familial
some due to underlying skeletal disorder, physeal injury with growth arrest or biochemical disorder

Question 6

skeletal disorder which can cause alignment disorder?

Answer 6

skeletal dysplasia

blounts disease

Question 7

name a biochemical disorder which can cause alignment disorder

Answer 7

rickets