Intraosseous plating: a new method for biodegradable osteofixation in craniofacial surgery

Biodegradable miniplates and screws offer special possibilities for surgical techniques because the removal operation is avoided. In areas beneath thin skin, intraosseous plating could be preferable to avoid palpability and transient swelling during resorption. The tissue reaction to a 0.5-mm-thick self-reinforced poly-L-lactide (SR-PLLA) plate fixed with an SR-PLLA miniscrew was studied histologically and histomorphometrically after implantation into the calvarium of six young sheep. After follow-up periods of 6, 20, and 52 weeks, no signs of adverse tissue reaction such as clinically manifest foreign body reaction or histologically manifest osteolysis were noted. By 52 weeks the implants were largely in direct contact with remodeled, dense bone tissue. No signs of fragmentation or resorption were noted in the intraosseous parts of the implants, whereas the screw head had been fragmented and was undergoing resorption at 52 weeks. The screw head is unnecessary in this plating method and could have been removed with a hot wire loop. The excellent biocompatibility of the mechanically strong, resorbable SR-PLLA plate with miniscrew fixation provides a possibility for intraosseous plating in less loaded craniofacial areas, especially in areas with very thin soft-tissue coverage.