Mechanobiologically-optimized non-resorbable artificial bone for patient-matched scaffold-guided bone regeneration

Scaffold-guided bone regeneration is poised to revolutionize the management of critical-sized bone defects. However, translation into clinical practice has been hampered by the focus on bioresorbable scaffolds where the rate of degradation needs to match the rate of bone formation and metal plates are required to overcome their mechanical limitations. Metal plates are problematic because they cause stress shielding and X-ray perturbation, increasing the likelihood of hardware failure and interfering with post-operative radiotherapy and imaging. Segmental defects of the mandible are challenging due to high tensile and shear stresses encountered during mastication, with the ovine mandible especially vexing because of the high repetitive loads. Here we show long-term reconstruction of ovine segmental mandibulectomy defects using a permanent, patient-matched, numerically optimized, 3D-printed, thermally toughened, plasma-treated, and laser-sintered polyetherketone gyroid scaffold housing a resorbable ceramic lattice infused with a stem cell laden hydrogel serving as an osteoinductive reservoir of calcium. The durable clinical performance observed indicates a translatable alternative to traditional reconstruction using bone grafts with metal plate fixation.