Biodegradable polyglyconate plates and screws: a histological evaluation in a rabbit model.

Within the zygomatic arch, bilateral osteotomies were performed on 20 adult male New Zealand white rabbits. These were stabilized in an anatomical position with polyglyconate acid plates and screws. At 3, 4, 6, 9, and 12 months, rabbits were killed and their zygomatic complexes removed en bloc. Specimens were serially sectioned for standard histological examination. Although no gross reactions were noted throughout the course of this investigation, histological reactions were brisk. At 3 months, particulate material was surrounded by a foreign body giant cell-type reaction. The quantity of foreign material appeared to decrease by 4 months, at which time the foreign body reaction was partially replaced by fibrous tissue. By 6 months, there was a thick periosteal scar at the osteotomy site with a few islands of persistent foreign material. These were primarily seen in small, irregular vesicular spaces surrounded by a large number of histiocytes with their characteristic foamy-cytoplasm. Although this foreign body reaction had subsided by 12 months, small foci of chronic inflammation still persisted.