The resorbable miniplate system Lactosorb in a growing cranio-osteoplasty animal model.

In the surgical treatment of craniosynostosis and craniofacial dysostosis in the growing child, passive intraosseous translocation (PIT effect) with intracranial displacement of metal plates and screws may be a problem. In an animal experiment, a possible PIT effect using resorbable PLA/PGA miniplates (Lactosorb, W. Lorenz, FL, USA) following cranio-osteoplasty were investigated in four young Göttingen minipigs. In addition to the mechanical properties, the processes of degradation and of sub- vs supraperiosteal application of the miniplates were evaluated. During degradation the resorbable PLA/PGA miniplates performed like metal plates as they also displayed passive intraosseous translocation in the growing animal model. However, in the experimental PLA/PGA miniplating the internal calvarial bone was not affected. Degradation took 12-18 months and was not delayed by bony incorporation. Mechanical properties proved to be sufficient in craniofacial surgery. Supraperiosteal plating delayed the PIT effect during the first 3 months after surgery. In the growing skull resorbable plates seem to be a promising therapeutic approach. However, prior to a general recommendation results of long-term clinical studies have to be evaluated.