Background: Ankylosed spines with ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis (DISH) are prone to fractures due to osteoporosis and fracture instability from long lever arm. In such cases, surgical management is the main treatment option. Case presentation: We report a first case of successful treatment of unstable bony Chance fracture at thoracolumbar junction in DISH patient using teriparatide and review previous literature on ankylosed spine fractures treated with teriparatide. An 82-year-old male patient presented with back pain after falling from a 3 m height 3 months ago. Imaging studies showed L1 unstable flexion-distraction injury (bony Chance fracture) and intravertebral vacuum cleft in ankylosed spine due to DISH. Conservative treatment, teriparatide and orthosis, was determined as the most appropriate approach because the patient declined surgery and presented with tolerable mechanical back pain without any neurologic deficits. Solid bony union was successfully achieved without any complications after 1-year treatment. Conclusion: Although surgical management is strongly recommended for unstable fracture in ankylosed spine, non-surgical treatment including teriparatide and orthosis might be safer and effective options in bony Chance fracture without neurologic deficits and intractable mechanical pain.