1. Department of Medicine (A.C., E.M.S, S.C., D.J.M., T.L.N., P.Y., E.S.), New York, New York 10032;
2. Department of Medicine (R.R.R., J.M.L., J.S.), Creighton University Medical Center, Omaha, Nebraska 68131;
3. Department of Pathology and Cell Biology (D.W.D.), Columbia University Medical Center, New York, New York 10032;
4. Regional Bone Center (D.W.D., H.Z.), Helen Hayes Hospital, West Haverstraw, New York 10993;
5. Institute for Biomechanics (R.M., A.Z.), ETH Zurich, 8093 Zurich, Switzerland