Prototype testing for a new bioabsorbable Le Fort III distraction device: a pilot study.
OBJECTIVE
The goal of the study was to design and test prototypes for a new, internal resorbable Le Fort III distractor in the minipig model.


METHODS
Le Fort III osteotomies were performed on 3 juvenile minipigs, followed by implantation of the bioabsorbable distractors. After a 5-day latency period, the distraction progressed at a rate of 1 mm/day in 2 equal increments for 12 days. This was followed by a 6-week consolidation phase. Cephalometric radiographs were taken postoperatively, on completion of distraction and after the consolidation phase, to evaluate the amount of distraction that was obtained. Necropsy was performed at the completion of each experiment.


RESULTS
The first minipig was sacrificed at the end of the distraction period because of device failure. On necropsy, it was noted that the anterior footplate on either side had failed. The second minipig was sacrificed during the latency period because of severe pneumonia. On necropsy, it was noted that none of the footplates had failed but that the distraction barrels on either side had become dislodged from the anterior bioabsorbable footplates. The third minipig was sacrificed at the end of the distraction period because of device failure. On necropsy, it was noted that the posterior bioabsorbable footplates on either side were fractured across the posterior screw lines.


CONCLUSIONS
The bioabsorbable devices evaluated in this study could not withstand the forces generated during distraction osteogenesis in the minipig model. Experience with the prototypes may help in designing internal bioresorbable Le Fort III distraction devices.
Gateno
Jaime
J
The University of Texas Health Science Center at Houston, Texas 77030, USA.
Seymour-Dempsey
Kelly
K
Teichgraeber
John F
JF
Lalani
Zahid
Z
Yanez
Rafael
R
Xia
James J
JJ
D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials; D001860:Bone Plates; D001863:Bone Screws; D004867:Equipment Design; D004868:Equipment Failure; D016268:Internal Fixators; D008422:Materials Testing; D008437:Maxilla / Q000601:surgery*; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D019340:Osteotomy, Le Fort / Q000145:classification / Q000295:instrumentation*; D010865:Pilot Projects; D013552:Swine; D013556:Swine, Miniature
D001672:Biocompatible Materials