Devices and methods in-situ produce articular spacers from a bone cement. The devices and methods have a punch surface for forming an articulation surface of a spacer in the bone cement, whereby the bone cement is arranged on a bone surface for fixation of the spacer, whereby the punch surface has a negative image of the articulation surface to be produced, and the surface forming the negative image is open on the side, at least in part, such that the bone cement can be pushed towards the side, away from the articulation surface to be formed. Moreover, the method for producing an articular spacer on a bone may have one or more of the following steps: A) Applying a bone cement to a prepared bone B) Pressing said device onto the bone cement and C) Detaching the device from the cured bone cement.
