Internal Lefort III and monobloc distraction with biodegradable devices

In spite of the many advantages of internal metallic distraction devices, they can be more difficult to remove. By substituting the metallic fixation plates of the Stryker-Leibinger Modular Internal Distraction system, with resorbable MacroPore fixation mesh, only the distractor screw and cable drive need to be removed. Moreover, by utilizing a resorbable stabilizer, the screw and cable components are not needed for the consolidation phase, and can be removed at the completion of active distraction. Herein, 33 patients undergoing internal craniofacial distraction are presented. The MID system was utilized in 21, while a new Macropore, biodegradable distractor was employed in 12. The report documents our results and demonstrates early success with a new type of bioresorbable device. Our initial concept was to link plates and screws to a buried driving device. [1] This, in theory, would permit easy adaptation to almost all anatomic sites and variants. Toward this coal, we worked with Leibinger ultimately developing the Modular Internal Distraction (MID) system (Stryker-Leibinger, Inc., Kalamazoo, MI). [2] The MID system allowed the surgeon to fabricate custom internal distraction devices for virtually any region of the craniofacial skeleton. The first generation system contains expansion screws capable of 15 mm and 30 mm. of distraction. Depending on the distraction site and osteotomy, any configuration of titanium plates could be attached to the distraction screw to permit uniplanar internal distraction. A flexible activation cable is brought out through a distant, inconspicuous stab wound in the hair behind the ear. The MID system has been used extensively. It's primary disadvantage has been the difficulty of removal. We prefer to remove all hardware whenever feasible. Thus, a second operation, which required similar exposure to the first was required for device explantation. To eliminate the difficulty of device removal, we worked with the development team at MacroPore, Inc. (San Diego, CA) to come up with a resorbable design. On November 19, 1999, the first resorbable distractor was employed in a 13 year old boy with hemifacial microsomia to correct severe malar hypoplasia. [3] The device worked well and was easy to remove. Furthermore, because of the development of a new biodegradable stabilization plate, the metallic driving device could be explanted at the conclusion of the distraction period. This permitted rapid and early device removal without the need for complete re-exposure. The biodegradable stabilization plate provided rigid fixation of the advancement, while protecting the underlying, immature bony regenerate. Consolidation was therefore allowed to take place, while eliminating the external cable and the attached metallic distraction screw.