DRUG
WJ-MSC
Other: subcutaneous injection of 20 µg teriparatide once daily for 6 months, followed by oral administration of anti-resorptive drug for 6 months. Other: intramedullary injection of 4 x 107 WJ-MSCs (direct injection into the recently fractured vertebra) at baseline (day 0). subcutaneous injection of 20 µg teriparatide once daily for 6 months, followed by oral administration of anti-resorptive drug for 6 months.