Romosozumab Effects on Bone Density, Muscle Mass, and Spine Surgery Outcomes

Inclusion Criteria: * Post-menopausal female * Diagnosed with osteoporosis (T-score ≤ -2.5). * Scheduled for or planning posterior lumbar fusion for degenerative disease, at least 3 months in the future. * Able to provide informed consent. Exclusion Criteria: * History of prior spinal surgery. * Male sex. * Current or prior use of osteoporosis medications within the past 3 years. * Current use of anabolic agents other than romosozumab. * Current use of androgen receptor (AR) modulators, such as testosterone replacement therapy or selective androgen receptor modulators (SARMs). * Severe renal impairment (eGFR \< 30 mL/min/1.73m²). * Known hypersensitivity to romosozumab, alendronate or zoledronic acid. * Severe spinal deformity. * Active malignancy or history of malignancy within the past 5 years. * Any secondary cause of decreased BMD (e.g., hyperparathyroidism). * Stroke or myocardial infarction in the past year. * Planned fusion involving more than 4 levels. * Uncorrected hypocalcemia and/or hypovitaminosis D * Esophageal abnormalities