StrAtegies For Zoledronic Acid Post-dEnosumab Discontinuation in Postmenopausal oSTeoporosis

Inclusion Criteria: * Women with post-menopausal osteoporosis * And treated with denosumab for at least 2 years and reaching decision of denosumab withdrawal because of achieved therapeutic target defined as no fracture during treatment; no new risk factors; no BMD decrease \> 0.03 g/cm² at the spine or hip; * And with a history of severe fracture or a femoral or lumbar T-score ≤ -2.5 prior denosumab initiation. Exclusion Criteria: * Dmab use for bone disease other than post-menopausal osteoporosis. * Uncontrolled endocrine diseases. Liver failure. * Use of medication affecting bone metabolism during the last year, including bisphosphonates, teriparatide, romosozumab, Selective Estrogen Receptor Modulators, breast cancer hormonotherapy, glucocorticoids over 5 mg/day. * Contra-indication to bisphosphonates according to license recommendation including chronic kidney disease with GFR stage \> or = G3b. Prior intolerance to zoledronic acid. * Subjects unable to give an informed consent or to fill the case report form. Subjects under law protection. * Foreseeable poor compliance with the strategy, alcoholism, toxicomania.