Reinforced bioresorbable implants for craniomaxillofacial osteosynthesis in pigs

Our aim was to design a new bioresorbable fixation device for craniomaxillofacial surgery based on reinforcement of fibres between 2 different polymers. The final device, the 2.8 mm polyglycolide fibre-reinforced-poly-l-lactide screw (PGA FR-PLLA; PLLA/PGA: 70%:30%), was evaluated for its mechanical properties and compared with a commercial resorbable device that was not reinforced with fibre. To model clinical conditions, a unilateral sagittal split ramus osteotomy fixation model in pigs was then used to compare the clinical effectiveness of the resorbable screw with that of a titanium screw in vivo, followed by 3-dimensional reconstructive imaging and histological analysis. Finally, an ex vivo biomechanical test was completed to investigate the immediate fixation stability of the newly designed screws. The PGA FR-PLLA screw resulted in clinical healing that was comparable to that of the titanium screw and was mechanically superior to the commercial device, indicating that the newly-developed screws have a potential clinical application.