A tissue positioning device comprising a biocompatible member having a size and shape suitable for placement within a space adjacent to a tissue to be positioned and which acts to maintain the tissue in a desired position. The member may be a rigid or flexible spacer having a defined shape, or a bladder capable of receiving and being at least partially expanded by a filler material. The device can made from a variety of materials or a composite of materials as needed, and may include one or more attachment means by which it can be secured to nearby tissues such that it is maintained in a desired spatial location. The filler material can be any of a number of substances, including liquids, gases, a curable liquid such as bone cement or urethane foam, or a spring.