polymeric medical fixation screws with multiple cannulations and thereby a reduced risk of shearing while being torqued into place are provided . the polymeric screws have at least two cannulae , on either side of a central longitudinal axis of the screw , extending parallel to the longitudinal axis . torquing instruments are inserted into the cannulae so that the applied torque force for driving the screws into a bone hole is distributed along the shaft of the screw . in one embodiment , the invention provides interference screws , while in other embodiments the invention provides medical fixation screws with heads and soft tissue - to - bone anchors or suture anchors . the polymeric screws may be fabricated from virtually any suitable biocompatible polymers or composites , including bioabsorbable polymers and their composites .