 Both the elastic stable intramedullary nailing system (ESIN) and flexible intramedullary nailing (FIN) use two bent elastic nails in order to allow for greater realignment and stability.This technique used in conjunction with a circular external fixator has been shown to significantly reduce Healing Index values in both monosegmental and polysegmental lengthening.Another advantage is that no fractures or deformities were found in later follow ups of 2 to 5 years.