A plug system (10', 10, 10") for preventing material from extruding beyond a desired location in a bone tunnel (42) includes a plug member (20', 20, 22") that has an insertion axis (2, 4, 206') extending from a first end (202', 202, 202") and a plurality of interleaving arms (205', 205, 205") disposed about the insertion axis. The arms (205', 205, 205") are affixed at a second end (204', 204, 204") and are flarable at the first end (202', 202, 202") between an insertion position wherein the arms (205', 205, 205") are relatively close packed and a position wherein the arms (205', 205, 205") are flared. A portion of each arm (205', 205, 205") remains in overlapping relation to an adjacent arm (205', 205, 205"). The system (10', 10, 10") further includes an expansion member (32, 30, 31) that has an insertion portion (321, 301, 311) adapted to separate the arms (205', 205, 205") upon progressive entry along the insertion axis (2, 4, 206') from the first end m(202'. 202. 202"). In use the plug (20', 20, 20") can be inserted either first end (202', 202, 202") first, with the expansion member (32, 30, 31) drawn into the plug (20', 20, 20") by a manipulator (33, 50), or second end (204', 204, 204") first, with the expansion member (32, 30, 31) driven along the insertion axis (2, 4, 206').