1. Bone Health and the Environment

2. Bone Functions Calcium HomeostasisCalcium Homeostasis –Calcium “bank” Skeletal IntegritySkeletal Integrity –Muscle –Nerve –endocrine

3. The Scientific Basis of Orthopaedics, Albright, James; Brand, Richard

4. Calcium Hydroxyapatite

5. The Scientific Basis of Orthopaedics, Albright, J; Brand, R.

6. Hydroxyapatite: a-axis projection of the crystal structure. The Scientific Basis of Orthopaedics, Albright, J; Brand,R.

7. A single crystal of hydroxyapatite Ca 5 (PO 4 ) 3 (OH) synthesized at 400°C and 2 kbar water pressure with a size of approximately 1 x 0.05 mm. The Scientific Basis of Orthopaedics, Albright, J; Brand, R.

9. STAGES OF BONE GROWTH AND LOSS Age in Years 102030405060708090 Active Growth Slow Loss Rapid Loss Less Rapid Loss

10. 2nd Decade of Life 5th Decade of Life 8th Decade of Life The Scientific Basis of Orthopaedics, Albright, J; Brand, R.

12. Determinants of Peak Bone Mass Genetic Influence Diet Exercise and activity Hormone Status

13. Genetic Influence

14. Relation of Alleles of the Collagen Type Ia1 Gene to Bone Density and the Risk of Osteoporotic Fractures in Postmenopausal Women André G. Uitterlinden, et al. Volume 338:1016-1021April 9, 1998Number 15

15. Calcium Requirement Age Group( years)Calcium mg/day Youth (0-11)800-1000 Young Adult (11-25)1200 Adult (25-50)1000 Post -menopausal1500

17. Modulators of Intestinal calcium absorption Increase Vit D Low Ca++ diet High Na+ diet PTH Phosphate depletion GH Estrogen Pregnancy Lactation Furosemide Decrease Aging High Ca++ diet Low Na+ diet Glucocorticoids Phosphate loading Thyroid Hormone Metabolic Acidosis Thiazides

18. Bone Loss Following Discontinuation of HRT -3.5 -3.0 -2.5 -2.0 -1.5 -0.5 0.0 0.5 1.0 Post-HRT Bone Loss (n=50) Postmenopausal Bone Loss (n=81)post Mean % Change ± SD from Baseline Number of Years Following Estrogen Cessation Trémollieres FA, et al. Osteoporosis Int. 2001;12:385–390. 0–2 years3–5 years6–8 years

19. Placebo-Treated Postmenopausal Women Rapidly Lose Microarchitectural Elements Baseline1 Year Dufrense, et al. OI 2002 World Congress on Osteoporosis

21. Exercise and Activity

24. Calcaneal BMD vs WHO Norms 0.436 0.500 0.530 0 0.4 0.8 Weight Lifters Swimmers WHO Norms Groups Areal BMD

25. The Scientific Basis of Orthopaedics, Albright, J; Brand, Richard

26. Bone Bank Mechanical Usage Effects on Bone Architecture The Scientific Basis of Orthopaedics, Albright, J; Brand, R.

28. Thank You