A patient specific trial repositioning block is disclosed which extends the know operating technique using patient-specific cutting blocks by virtue of the fact that the soft-tissue situation or ligament tension conditions can be checked and corrected intraoperatively. The trial repositioning block can be dimensioned according to the tibia structure and femur structure. During use of the trial positioning block in an operation, the block can bring the femur to lie in a planned corrected end position on the tibia. Trial repositioning can be performed after the sectioning of the tibia, and the operator, after sectioning of the tibia, can already have an accurate picture of the end result of the operation.
