title: Degradation characteristics of PLLA-PGA bone fixation devices.
abstract: Parietal craniotomies of the mature rabbit skull were repositioned and fixed with resorbable plate and screws made of LactoSorb (Walter Lorenz Surgical, Jacksonville, FL) poly L-lactic acid (PLLA) and polyglycolic acid (PGA) in 20 mature rabbits. Changes in the resorbable devices as well as at the tissue-implant interface were evaluated at 2, 6, 9, and 12 months postoperatively. At 2 months, no change in the size of the implants was seen with a noninflammatory layer of surrounding fibrous tissue and intense birefringence of the screws. At 6 months, substantial loss of implant size had occurred, accompanied by fibrovascular and a macrophage cellular infiltrate. At 9 months, more than 95% of the implant was resorbed, with a small amount remaining in the screw hole. Other than macrophages within the remaining material, very few giant cells were seen. By 1 year, no evidence of birefringent macromolecular polymer debris could be found. No contraindications for the clinical use of this specific PLLA-PGA copolyer could be found when implanted on craniofacial bone surface.
authors.affiliation: Division of Plastic Surgery, Indiana University Medical Center, Indianapolis 46202-5200, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Eppley
authors.forename: M
authors.initials: M
authors.lastname: Reilly
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001860:Bone Plates; D001863:Bone Screws; D003399:Craniotomy / Q000295:instrumentation; D019344:Lactic Acid / Q000378:metabolism*; D016348:Osseointegration; D011100:Polyglycolic Acid / Q000378:metabolism*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000378:metabolism*; D011817:Rabbits
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid