As part of an observational study, twenty female osteoporosis patients looking to transition off denosumab therapy will be recruited from the David Hanley Osteoporosis Centre and affiliated primary care physicians in Calgary. The decision to stop denosumab will be made in accordance with standard clinical care and fully separate from the present study. Approximately 6-8 months after the patients' final denosumab injection, patients will receive a single infusion of zoledronic acid (5 mg/100mL) as part of their routine standard of care. The 6-8 month time frame corresponds with the recommended duration between subsequent denosumab injections. Concurrent with zoledronic acid treatment (within one month before or after infusion), patients will visit to the McCaig Institute for Bone and Joint Health to receive a baseline dual X-ray absorptiometry scan (lumbar spine, lateral vertebral assessment, and hip) and a high-resolution peripheral computed tomography scan (radius and tibia) to quantify areal BMD and volumetric BMD/bone microarchitecture, respectively. They will also complete the MoJo Fracture Risk Questionnaire. Patients will return for repeat scanning and questionnaire administrations to monitor potential changes to bone at 6 and 12 months after baseline. Any fracture events during the 12-month time frame will be logged in consultation with the patients' physician as documented through routine clinical follow-up. Researchers may contact participants to repeat scanning and questionnaire administration at the 24-month time point, if participants agree to this contact within the informed consent.
This two-year observational, open-label clinical trial will evaluate the efficacy of a once-yearly infusion of zoledronic acid after denosumab discontinuation to maintain tissue mineral density and bone microarchitecture using high-resolution peripheral quantitative computed tomography (HR-pQCT) among post-menopausal women with osteoporosis.