A device for preparing multiple channels in a bone comprises a handle, a single guiding sleeve mounted removable at said handle and an arm projected from said handle. Said single guiding sleeve comprises a central first guiding channel for receiving a first aiming wire, a second guiding channel for receiving a further aiming wire, said channels have parallel axes. At least one cannulation is provided, a central longitudinal axis thereof runs at a distance and parallel to the guiding channels. Said at least one cannulation being arranged offset in a circumferential direction to said second channel. An aiming wire introduced in said second channel can be replaced into a cannulation by pulling off the guiding sleeve turning it about the first aiming wire and reinserting the turned guiding sleeve into said handle.