Question special

Thanks to the author and experts for devoting time for the discussion. I'd like to start by asking about trial design. While FDA trials for osteoporosis recommend vertebral BMD as an endpoint in phase 3 osteoporosis trials, do you think it is a valid BMD site as a primary endpoint compared to the load-bearing femoral neck in very elderly patients given the increased likelihood of osteoarthritis and aortic calcification in this population, which may affect DEXA results?