A suture anchor includes a material having thermoplastic properties and is fixated in a hard tissue opening by liquefying at least part of this material and letting it penetrate into walls of the hard tissue opening. During the named fixation and preferably towards the end of it, the suture being held in a distal suture conduit is locked relative to the hard tissue by being clamped between the suture anchor and the wall of the hard tissue opening or by being clamped or braked through collapse of the suture conduit.