Woo SH, Goh TS, Ahn TY, et al. - This study was undertaken to investigate the results of subtalar distraction arthrodesis (SDA) for calcaneal malunion applying structural freeze-dried iliac allograft (FDIA) compared to using autologous iliac bone. In this study, 57 consecutive cases (51 patients) of calcaneal malunion were retrospectively examined between March 2006 and December 2017. More favorable clinical and radiologic outcomes in the autologous iliac bone group were obtained, although the union rate was not significantly different between the two groups. There was significantly more loss of radiological parameters due to inferior incorporation and biomechanical properties applying FDIA without any ortho biological agent for SDA. The data revealed that the routine use of FDIA without any ortho biological agents as an interpositional graft for SDA is not recommended when considering the SDA for calcaneal malunion.