PULLOUT STRENGTH OF ADAPTION SCREWS IN THYROID CARTILAGE

Purpose: To determine the pullout strength of adaption screws in laryn geal cartilage and its relationship to drill hole and screw diameter. Materials and Methods: Screw pullout strength in human cadaver thyroid cartilage was measured using a load cell. Screw sizes of 1.3, 1.5, an d 2.0 mm were tested using drill hole diameters of 0.76, 1.1, and 1.5 mm. Results: Maximum pullout strength was achieved using a drill hole diameter of 0.76 mm and a 1.5 mm screw. Pullout strength for this comb ination was 27.5 N. Conclusion: Adaption screws can be used in thyroid cartilage but pullout strengths will be less than in bone. Drill hole s for screws in thyroid cartilage should be smaller than those used fo r cortical bone. Maximum strength will be achieved using a 1.5 mm scre w in a 0.76 mm drill hole. Copyright (C) 1998 by W.B. Saunders Company .