Osteoporosis in Primary Hyperparathyroidism

Inclusion Criteria: * Postmenopausal women (\>12 months after last menstrual period) with primary hyperparathyroidism and with osteoporosis on Dual Energy Xray Absorptiometry (DXA) (according to International Society for Clinical Densitometry (ISCD) - criteria) and/or osteoporotic fracture of the vertebra or hip Exclusion Criteria: * The patient is not able to give informed consent * other classic complications of primary hyperparathyroidism (e.g. kidney stones, renal insufficiency) * serum albumin-corrected calcium level \> 2.85 mmol/L (except when the patient is reluctant to undergo surgical treatment) * osteoporosis treatment less than a year ago, less than two years ago in the case of oral bisphosphonate, less than three years ago in the case of parenteral bisphosphonate * bilateral hip endoprosthesis * additional causes for secondary osteoporosis (other than vitamin D deficiency) and pathological laboratory findings that are incompatible with the Summary of Product Characteristics (SmPC) of both medicines * cancer, except if in stable remission of more than 5 years