increased anteversion of the femoral neck relative to the femur
compensatory internal rotation of the femur
lower extremity intoeing
Epidemiology
demographics
seen in early childhood (3-6 years)
twice as frequent in girls than boys
can be hereditary
location
often bilateral
be cautious of asymmetric abnormalities
Pathophysiology
a packaging disorders caused by intra-uterine positioning
most spontaneously resolve by age 10
Associated conditions
can be seen in association with other packaging disorders
DDH
metatarsus adductus
congenital muscular torticollis
Prognosis
multiple studies have been unable to reveal any association with degenerative changes in the hip and knee when increased anteversion persists into adulthood
Anatomy
Is based on degree of anteversion of femoral neck in relation to the femoral condyles
at birth, normal femoral anteversion is 30-40°
typically decreases to normal adult range of 15° by skeletal maturity
minimal changes in femoral anteversion occur after age 8
Presentation
Symptoms
parents complain of an intoeing gait in early childhood
child classically sits in the W position (see above image)
knee pain when associated with tibial torsion
awkward running style
when extreme in an older child occasional functional limitations in sports and activities of daily living can occur
difficulty with tripping during walking or running activities
can be more symptomatic in those with neuromuscular diseases and brace-dependent walkers
secondary to lever-arm dysfunction and decreased compensatory mechanisms
Physical exam
evaluation for intoeing
femoral anteversion
hip motion (tested in the prone position)
increased internal rotation of >70° (normal is 20-60°)
decreased external rotation of < 20° (normal 30-60°)
anteversion estimated on degree of hip IR when greater trochanter is most prominent laterally
trochanteric prominence angle test
patella internally rotated on gait evaluation
tibial torsion
look at thigh-foot angle in prone position
normal value in infants- mean 5° internal (range, −30° to +20°)
normal value at age 8 years- mean 10° external (range, −5° to +30°)
metatarsus adductus
adducted forefoot deformity, lateral border should be straight
a medial soft-tissue crease indicates a more rigid deformity
evaluate for hindfoot and subtalar motion
Imaging
Radiographs
recommended views
none required typically
CT or MRI
may be useful in measuring actual anteversion
Treatment
Nonoperative
observation and parental reassurance
indications
most cases usually resolve spontaneously by age 10
technique
bracing, inserts, PT, sitting restrictions do not change natural history
Operative
derotational femoral osteotomy
indications
< 10° of external rotation on exam in an older child (>8-10 yrs)
rarely needed
technique
typically performed at the intertrochanteric level
amount correction needed can be calculated by (IR-ER)/2