The invention relates to a reinforcing implant for the lamina (93) of a vertebra, comprising a transverse carrier and an anchoring device for each of the right side and the left side of the lamina of the vertebra. An expansion element (1) comprising a guiding device (2) and jaw elements (4, 4') is provided, said jaw elements being mounted along the guiding device in a longitudinally movable manner. Bearing surfaces (43) for the lamina are embodied on outer sides of the jaw elements (4, 4') facing away from each other, and a return stop is provided for the jaw elements. At least one of the jaw elements is provided with an alignment device for the variable orientation of its bearing surface (43) in relation to the guiding device (2). In this way, a secure anchoring of the reinforcing implant in the cut sections created during the laminectomy can be obtained, with precise adaptation of the reinforcing implant to the actual anatomical conditions following the laminectomy and with elastic expansion of the vertebral arch in order to increase the fixing reliability.
