title: Maxillary and mandibular osteosyntheses with PLGA and P(L/DL)LA implants: a 5-year inpatient biocompatibility and degradation experience.
abstract: BACKGROUND
  This study consists of a 5-year experience with 413 maxillary and mandibular resorbable plate osteosyntheses focusing on clinically apparent foreign body reaction (i.e., swelling, osteolyses, and fistulation), indirect implant degradation (i.e., palpability and radiographic reossification), and direct implant degradation (i.e., molecular weight and crystallinity of explants).
  
  
  METHODS
  Eighty fracture and reconstruction cases (32 female and 48 male patients, aged 1 to 83 years) were osteofixated with poly(L-lactide-co-glycolide) (PLGA) copolymer (n = 20) (139 PLGA osteosyntheses) or poly(L-lactide-co-DL-lactide) [P(L/DL)LA] (n = 60) [274 P(L/DL)LA osteosyntheses]. Local revisions (n = 30) were performed during secondary operations at 3, 6, 12, 18, or 24 months. Average clinical and radiographic follow-up lasted 29 months (range, 6 to 63 months).
  
  
  RESULTS
  Five patients (6 percent) had apparent foreign body reactions, whereas 75 (94 percent) did not. One P(L/DL)LA mild reaction was effectively treated with cold packs and analgesics, one PLGA and three P(L/DL)LA medium severe reactions were treated with curettage, and one local osteolysis disappeared at 6 months. Implant palpability lasted 12 (PLGA) or 24 months [P(L/DL)LA]. The difference was significant (p < 0.000001). Burr holes reossified at 24 (PLGA) and 36 months [P(L/DL)LA] (p < 0.05). The 85:15 PLGA explants' initial 44,600 molecular weight decreased to 11,000 at 6 months; and scarce powdering granular residuals, too small for molecular weight assessment, were encountered at 12 months. The 70:30 P(L/DL)LA initial molecular weight of 45,000 decreased to 25,000 at 6 months and 8,000 at 18 months and to similar granules at 24 months (p < 0.02). Histology showed macrophages, giant cells, lymphocyte infiltration, little granulocytic infiltration, and minimal bleeding residuals.
  
  
  CONCLUSIONS
  Both copolymers showed reliable biocompatibility and disintegration. Overall, 6 percent clinically apparent foreign body reactions were controlled conservatively and by local curettage; 85:15 PLGA degraded within 12 months and 70:30 P(L/DL)LA within 24 months, leaving powdering residual granules. Burr holes reossified 12 months later.
authors.affiliation: Maxillofacial and Facial Plastic Surgery, J. W. Goethe University Medical Center, Frankfurt, Germany. c.landes@lycos.com
authors.forename: Constantin A
authors.initials: CA
authors.lastname: Landes
authors.forename: Alexander
authors.initials: A
authors.lastname: Ballon
authors.forename: Christian
authors.initials: C
authors.lastname: Roth
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001672:Biocompatible Materials / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D005549:Foreign-Body Reaction / Q000209:etiology* / Q000628:therapy; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D007223:Infant; D007572:Jaw Fractures / Q000601:surgery*; D019344:Lactic Acid / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008337:Mandibular Fractures / Q000601:surgery; D008440:Maxillary Fractures / Q000601:surgery; D008447:Maxillofacial Prosthesis; D019931:Maxillofacial Prosthesis Implantation / Q000009:adverse effects; D008875:Middle Aged; D011091:Polyesters / Q000009:adverse effects / Q000627:therapeutic use; D011100:Polyglycolic Acid / Q000009:adverse effects / Q000627:therapeutic use*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000009:adverse effects / Q000627:therapeutic use*; D011475:Prosthesis Failure; D012086:Reoperation
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)