[Study on macro- and micro-mechanical properties of bone regenerative tissue during the healing process of spinal intervertebral fusion devices].

Following spinal fusion surgery, the mechanical properties of macroscopic bone regenerative tissue and microscopic bone cells during daily activities remain unclear. This study employed a submodel approach to establish connections between bone regenerative tissue and bone cells, simulating human physiological activities to obtain stress-strain data at both macro- and micro-scales across various stages and working conditions. Results indicate that vertical external forces significantly impact bone healing. Patients should minimize large-amplitude forward flexion and right rotation movements during the early healing phase. Once healing is largely complete, appropriate activity is safe, though caution should still be exercised to avoid large-amplitude forward flexion, left rotation, and right lateral flexion movements. This study investigated healing variations in regenerated bone tissue across different end-face orientations, regions, and operational conditions during the healing process. It provides a theoretical basis for developing movement guidelines that promote healing during the postoperative recovery phase for patients who have undergone spinal fusion surgery.