Abstract
We report the case of a 75-year-old woman who developed rapidly progressive epidural calcification with vertebral destruction after initiation of romosozumab, followed by regression after the medication was discontinued. The patient, who had a prior history of pyogenic spondylodiscitis and was on maintenance hemodialysis, developed new-onset severe low back pain three months after starting romosozumab. Radiographic evaluation confirmed extensive epidural and perivertebral calcification with vertebral body destruction. A CT-guided drainage provided symptomatic relief, and microbiological cultures were negative for infection. After discontinuation of romosozumab, serial imaging demonstrated progressive regression of calcification, and the patient remained asymptomatic at follow-up without recurrence of pain or evidence of infection. This case highlights a rare but clinically significant complication of romosozumab therapy, which is ectopic epidural calcification with structural damage in the setting of chronic kidney disease (CKD) and pre-existing spinal pathology. Awareness of this phenomenon is crucial to avoid misdiagnosis as recurrent infection, to prevent unnecessary interventions, and to ensure timely discontinuation of the offending agent. Further recognition may help refine monitoring strategies and guide safer use of osteoanabolic agents in high-risk populations.