Foot　and　ankle　deformity　remains　a　common　presenting　complaint　in　orthopedic　surgery.　External　fixator　is　a　key　medical　device　to　assist　gradual　correction.　Its　configuration　selection　has　a　significant　influence　on　correction　results.　Among　two　external　fixators　currently　used　in　clinic,　conventional　Ilizarov　external　fixator　(IEF)　has　high　use　difficulty　and　low　accuracy,　whereas　the　single　configuration　of　later　hexapod　external　fixator　(HEF)　leads　to　inadequate　adaptation　to　diverse　deformity　types　in　foot　and　ankle.　To　solve　the　above　problems,　this　paper　presents　a　novel　parallel　distraction　apparatus　(PDA).　First,　corrective　degree-of-freedom　(c-DOF)　is　defined　to　determine　expected　posture　transformation　of　external　fixator　required　by　corrective　manipulation.　By　summarizing　and　classifying　c-DOF,　predominant　foot　and　ankle　deformities　with　fewer　correction　requirements　are　divided　into　six　types.　Subsequently,　six　lower-mobility　parallel　mechanisms　are　introduced　as　the　configurations　of　external　fixators　via　the　c-DOF　based　configuration　synthesis　approach.　After　performing　reconfigurable　structural　design,　PDA　can　respectively　form　six　types　of　parallel　external　fixators　for　six　deformity　types.　Finally,　clinical　case　simulations　are　provided　to　verify　the　application　potential　and　advantages　of　PDA.