Achterman and Kalamchi classification of fibular hemimelia. Type 1A: proximal fibular epiphysis is more distal, and distal fibular epiphysis is more proximal than normal. Type 1B: more severe deficiency of fibula with at least 30% to 50% of fibula missing and no distal support to ankle joint. Type 2: complete absence of fibula with bowing and shortening of tibia.