In Vivo Inflammatory Soft and Hard Tissue Response to Newly Developed Osteosynthesis Material for Pediatric Maxillofacial Traumatology in a Critical Size Bone Defect Model

Childhood trauma defects in the head and neck area are challenging in many aspects for patients and surgeons. One major issue is the still incomplete growth. Bone defect fixation measures have to consider biomechanical forces due to the bone growth from both sides, the bone growth possibly influencing and working against the fixation itself and vice versa. A solution will be the development of a stable but, at the same time, quickly degradable osteosynthesis system (OSS) specifically for the pediatric sector. Besides the physical demands, biocompatibility and low risk for unphysiological tissue response are exceptionally important. A newly developed PDLLA-derivate/chitosan hybrid material (PDLLA:CC:Mg+Chitosan) with promising features confirmed in vitro experimental set-ups has been tested in a critical size bone defect model in Wistar rats to confirm slow degradation and absence of unphysiological integration of the material, and of bone growth induced by the material itself. mCT and histologic analysis of implanted rat skulls after 1, 3, and 5 months confirmed slow degradation of the PDLLA:CC:Mg+Chitosan material without any unintended bone growth induction or morphologic changes due to the material. The results of this in vivo study confirmed the suitability of the material to serve as OSS in clinical practice.