µMRI of Therapeutic Intervention in Postmenopausal Osteoporosis

The overall design is to determine and compare the effect of teriparatide and of zoledronic acid on trabecular architecture by magnetic resonance imaging of the midshaft tibia. Post-menopausal women, aged 60 or older with osteoporosis and/or at increased risk of fracture, will be randomized to receive either teriparatide or zoledronic acid. Trabecular microarchitecture, biomechanical parameters and bone mineral density will be examined at 0 and 12 months at 3T MRI.

Inclusion criteria

• Women
• Age ≥ 60 years
• Bone mineral density T-score of either the spine (L1-L4), total hip or femoral neck of ≤ - 2.0, or has a history of an osteoporotic fracture

Exclusion criteria

• Previous treatment with pamidronate, ibandronate, of more than 2 doses in 2 years and of zoledronic acid at any time
• Previous treatment with teriparatide, alendronate or risedronate of more than 2 months in the last 24 months
• Previous treatment with calcitonin within the previous year; previous treatment with an estrogen or selective estrogen modulator will not exclude a potential subject unless she has been taking it for < 1 year (a woman who discontinued estrogen or a selective estrogen receptor within the previous year will also be excluded)
• Other diseases known to affect bone, such as Paget's disease, Cushing's disease, hyperthyroidism, hyperparathyroidism, bone cancer and metastases to bone, and vitamin D deficiency
• Medications known to affect bone, such as anticonvulsants, high dose glucocorticoids (20 mg/day or more > 2 weeks within the previous 6 months)
• Current alcohol use > 3 drinks/day
• Untreated or unstable cardiac, pulmonary, liver (SGOT > 2X upper limit of normal) or renal disease (creatinine > 1.2 mg/dL) or uncontrolled diabetes (hemoglobin A1C > 8.0)
• Prior radiation therapy to the skeleton
• Cardiac pacemakers, ferromagnetic implants or brain aneurysm clips
• Claustrophobia
• Subjects whose initial MRI is of poor quality due to motion artifact will be asked to repeat the examination; if a repeat MRI is of poor quality due to motion artifact, the subject will be excluded from the study
• Abnormalities of the which delay esophageal emptying such as stricture or achalasia
• Inability to stand or sit upright for at least 30 minutes
• Hypocalcemia
• Uric acid level >7.5ml/dl
• Subjects with metallic objects in their bodies