The present invention provides a retractor assembly capable of supporting at least a tissue engaging member in a manner allowing self alignment of the member subject to the pull force of the tissue engaged by the member. The retractor assembly comprises: (i) a frame member which supports a support member; (ii) at least one tissue engaging member which possesses at least a mounting arrangement which is capable of releasably engaging the support member; and (iii) a locking member which is capable of releasably engaging the tissue engaging member with the frame member and the support member to hold the tissue engaging member(s) in a substantially immovable position.