An apparatus for replacing a human ankle joint, the apparatus comprising: a tool positioning jig for setting a position of a tool holder relative to a part of a person's anatomy； a cyclical saw removably mountable to the tool holder for making a distal tibial cut though the person's tibia bone； a talus positioning guide removably mountable to the tool holder for setting a position of location holes to be drilled in the person's talus bone； a talus re-section guide, alignable with the location holes to be drilled in the person's talus bone, for providing a cutting face for making a superior talar cut through the person's talus bone； an ankle alignment jig for setting the position of one or more slots in the person's tibia bone, the said one or more slots being configured to receive a first portion of an artificial ankle joint, and for setting the position of one or more guide holes to be drilled in the person's talus bone in order to facilitate medial, lateral, posterior and anterior alignment of the first portion of the artificial ankle joint with a second portion of the artificial ankle joint； a talus drill template comprising one or more dowels, or pins, configured to be received by the one or more guide holes to be drilled in the person's talus bone, the talus drill template further comprising one or more drill guides for setting the position of at least one further hole to be drilled in the person's talus bone； a talus roof top preparation guide comprising at least two dowels, or pins, configured to be received respectively by the one or more guide holes to be drilled in the person's talus bone and by the at least one further hole to be drilled in the person's talus bone, the roof top preparation guide further comprising two large diameter holes for receiving a cutting tool for removing a portion of the person's talus bone； a talus routing guide for setting the position of one or more slots in the person's talus bone, said one or more slots being configured to r
