Objective To explore the application effect of different ratios of mineralized collagen modified bone cement in osteoporotic thoracolumbar vertebral fractures. Methods A retrospective analysis was conducted on the medical records of 376 elderly patients with osteoporotic thoracolumbar fractures admitted to the hospital from February 2018 to October 2023. According to the bone cement ratio, they were divided into an observation group of 206 cases and a control group of 170 cases. The observation group and the control group were filled with 15% mineralized collagen and 20% mineralized collagen mixed with methyl methacrylate, respectively. The patients were followed up for 6 months after operation, and the recovery of vertebral height, biomechanics and activities of life were compared between the two groups. Results The height percentage of the anterior edge and the middle of the injured vertebra in the observation group and the control group were significantly higher than those before operation (P < 0.05). The Cobb angle of local kyphosis of the injured vertebra in the observation group and the control group was significantly decreased compared with that before operation(P < 0.05). After surgery, there was an increase in stress on the T11 lower endplate, T11/T12 intervertebral discs, T12/L1 intervertebral discs, and L1 upper endplate in both groups (P<0.05), with the observation group being lower than the control group (P<0.05). After surgery, the stress levels of T11/T12 intervertebral discs and T12/L1 intervertebral discs increased under flexion rotation torque in both groups (P<0.05), and the observation group was lower than the control group (P<0.05). Before surgery, 48 hours after surgery, and 6 months after surgery, the Oswestry Disability Index scores of the two groups gradually decreased (P<0.05). Conclusions Mineralized collagen modified bone cement filling treatment for elderly osteoporotic thoracolumbar fractures can promote the recovery of vertebral height, balance the stress distribution between adjacent vertebral bodies, and improve postoperative activity ability of patients.