Fibular Deficiency (anteromedial bowing)

Question 1

Three types of tibial bowing exist in children

Answer 1

• anterolateral bowing (neurofibromatosis)
• posteromedial bowing (physiologic)
• anteromedial bowing (this topic)

Question 2

Associated conditions

Answer 2

• anteromedial tibial bowing
  
  • most common cause is fibular hemimelia
• ankle instability
  
  • secondary to a ball and socket ankle
• talipes equinovalgus
• tarsal coalition (50%)
• absent lateral rays
• femoral abnormalities (PFFD, coxa vara)
• developmental dysplasia of the hip
• cruciate ligament deficiency
• genu valgum
  
  • secondary to lateral femoral condyle hypoplasia
• significant leg length discrepancy
  
  • shortening of femur and/or tibia

Question 3

Radiographs

Answer 3

• fibula is either absent or shortened
• tibial spines are underdeveloped
• intercondylar notch is shallow
• ball and socket ankle joint
  
  • secondary to tarsal coalitions

Question 4

Goals

Answer 4

treatment determined by the stability and level of foot and ankle function, as well as the degree of limb shortening

• not based on amount of fibula present