8) Inability to sit or stand for at least 30 minutes, 9) Known allergy or intolerance to alendronate or denosumab, or any of their excipients, 10) Hypocalcaemia, 11) Maintenance calcium supplementation, 12) Dental extraction within 6 months, 13) History of osteonecrosis of the jaw, 14) Major or untreated cancers, 15) Poor dental hygiene, 16) Women of child-bearing potential who have experienced menarche, are pre-menopausal, have not been sterilised or who are currently pregnant, 17) Women who are breastfeeding, 18) Renal failure (estimated glomerular filtration rate of <30 mL/min), 19) Allergy or contraindication to iodinated contrast, 20) Inability or unwilling to give informed consent, 21) Likelihood of non-compliance to treatment allocation or study protocol