Biodegradable miniplates (LactoSorb): Long-term results in infant minipigsand clinical results

Metallic plates are known for their passive intraosseous transmission in th e growing skull. To avoid plate removal, resorbable material with strength comparable to that of metallic plates and predictable resorption would be d esirable. This should be accomplished without causing inflammatory complica tions and foreign body reactions often seen with highly crystalline poly-L- lactic acid or pure polyglycolic acid implants. In an animal experiment in four young Gottingen minipigs, the resorbable poly-L-lactic acid/polyglycol ic acid copolymer LactoSorb was tested previously. In addition to testing t he mechanical properties, the process of degradation and sub- versus epi- o r supraperiosteal application of the miniplate device LactoSorb was evaluat ed using a frontal cranioosteoplasty model. Furthermore, LactoSorb was used in 10 patients with craniosynostosis or craniofacial trauma. During degrad ation, the absorbable poly-L-lactic acid/polyglycolic acid miniplates acted like metal plates because they also displayed passive intraosseous transmi ssion in the growing animal model. Degradation took 12 to 18 months and was not delayed by bony incorporation. Their mechanical properties proved to b e sufficient in craniofacial surgery. Epiperiosteal plating prolonged the p assive intraosseous transmission effect during the first 3 months after sur gery. There were no major inflammatory reactions seen in the experimental a nd/or in the clinical study.