Experimental and clinical evaluation of laryngeal chondrosynthesis.

The aim of this study was to investigate and develop techniques for stabilization and reconstruction of laryngeal defects with a method similar to osteosynthesis. In an anatomical study, 400 extrusion forces of sutures and various screws (Howmedica) were measured in the thyroid cartilage of fresh cadavers. A new screw was then especially designed for cartilage and a new technique was developed for stabilizing cartilage, using a screw-nut made out of bone. To date, 30 patients have undergone chondrosynthetic reconstruction of the larynx. Measurements of extrusion forces were found to depend on the degree of calcification present in the area of the laryngeal skeleton examined and the type of fixation device used. Good clinical results were achieved in all 30 patients studied and depended on stabilization of the two sides of the thyroid cartilage after thyrotomies, bridging of laryngeal defects and splinting of laryngeal fractures. Besides the increased extrusion forces the advantages of chondrosynthesis lay within the possibilities of axial stabilization and exact bridging of defects with or without implants.