SUMMARY 

• Femoral Anteversion is a common congenital condition caused by intrauterine positioning which lead to increased anteversion of the femoral neck relative to the femur with compensatory internal rotation of the femur. 

• Diagnosis is made clinically with the presence of intoeing combined with an increase in internal rotation of the hip of greater than 70° with an accompanying decrease in external rotation of the hip of less than 20°.

• Treatment is observation with parental reassurance as most cases resolve by age 10. Rarely, surgical management is indicated in the presence of less than 10° of hip external rotation in children greater than 10 years of age.

EPIDEMIOLOGY

• Demographics

  • seen in early childhood (3-6 years)

  • twice as frequent in girls than boys

  • can be hereditary

• Anatomic location

  • often bilateral

    • be cautious of asymmetric abnormalities

ETIOLOGY

• Femoral anteversion is characterized by

  • increased anteversion of the femoral neck relative to the femur

  • compensatory internal rotation of the femur

  • lower extremity intoeing

• There are three main causes of intoeing including

  • femoral anteversion (this topic)

  • metatarsus adductus (infants) 

  • internal tibial torsion (toddlers) 

• 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 

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 (>10 yrs)

      • rarely needed

    • technique

      • typically performed at the intertrochanteric level

      • amount correction needed can be calculated by (IR-ER)/2

PROGNOSIS

• Multiple studies have been unable to reveal any association with degenerative changes in the hip and knee when increased anteversion persists into adulthood