Falls and Fracture in the Elderly

1. Falls and Fracture in the Elderly Tuan V. Nguyen Bone and Mineral Research Program Garvan Institute of Medical Research

2. Overview • Osteoporosis • Magnitude of the problem • Bone mineral density (BMD) and fracture • Falls: etiology and risk factors • Fracture and fall

3. Osteoporosis: shift in thinking Low bone mass, microarchitectural deterioration of bone tissue leading to enhanced bone fragility and a consequent increase in fracture risk (Consensus Development Conference, 1991) “[…] compromised bone strength predisposing a person to an increased risk of fracture. Bone strength primarily reflects the integration of bone density and bone quality”(NIH Consensus Development Panel on Osteoporosis JAMA 285:785-95; 2001)

4. Osteoporosis in risk-and-outcome view RISK FACTOR OUTCOME Osteoporosis Fracture Bone Quality Bone Mineral Density Bone Strength and Architecture Turnover rate Damage accumulation Degree of mineralization Properties of the collagen/mineral matrix

5. Normal vs osteoporosis

6. Breaking bones

7. Incidence of all-limb fractures

8. Increase in life expectancy WHO. Human Population: Fundamentals of Growth World Health, 2000.

9. The ageing of population Percent of population aged 65+ ABS and US Bureau of Census, 1996.

10. Annual fracture incidence in Australia 1996-2051 Projected annual number of all-limb fractures in Australia aged 35+ (Sanders et al, MJA 1999)

11. Hip, vertebrae, and Colles fractures Projected annual number of all-limb fractures in Australia aged 35+(Sanders et al, MJA 1999)

12. Lifetime risk of some diseases - women Any osteoporotic fracture Hip fracture Clinical vertebral fracture Cancer (any site)* Breast cancer* Lung/bronchus* Coronary heart diseases Diabetes Mellitus *, from birth (from the age of 50)

13. Lifetime risk of some diseases - men Any osteoporotic fracture Hip fracture Clinical vertebral fracture Cancer (any site)* Prostate cancer* Lung/bronchus* Coronary heart diseases Diabetes Mellitus *, from birth (from the age of 50)

14. Consequences of fracture • Reduced mortality • Increased morbidity • Reduced quality of life • Incurred significant health care costs

15. Survival probability with and without fracture Source: Nguyen et al, 2005

16. Risk of death from hip fracture • 50-year old women: Lifetime risk of mortality from: • Hip Fracture: 2.8% • Breast Cancer: 2.8% • Endometrial Cancer: 0.7% Cummings et al. Arch Intern Med 1989; 149: 2445-8

17. Impact of hip fractures • 25% die within 6 months (*) • 60% have restricted mobility (*) • 25% remain functionally more dependent • Cardiac (8%) and pumonary complication (4%) • Transient heart attacks • Non-union and avancular necrosis

18. Impact of vertebral fractures • Symptomatic fx : Lifetime risk 1/4 women, 1/8 men • Asymptomatic fx prevalence: 20-30% • Back pain, functional limitation • Rib-against-pelvis (RAP) syndrome • Costoiliac impingement syndrome • Decrease vital lung capacity

19. Asymptomatic vertebral fracture increases risk of subsequent fractures 300 m+w 66 V # 234 No V # 29 Fx 37 no fx 180 no fx 54 Fx 44% 23% Pongchaiyakul C et al, J Bone Miner Res 2005

20. Asymptomatic vertebral fracture increases risk of death 300 m+w 66 V # 234 No V # 20 deaths 46 survived 209 survived 25 deaths 30% 11% Pongchaiyakul C et al, J Bone Miner Res 2005

21. Impact of wrist fracture • More common in women in their 50s • Post-traumatic arthritis • Account for 39% of all physical therapy sessions • Reduced daily living activies Melton LJ, J Bone Miner Res 2003

22. Fracture Prediction

23. A model for assessing fracture risk Other factors (age, weight, structural factors) Interaction between BMD and fall-related factors in the prediction of hip fracture Quadriceps weakness # Falls Postural instability Low bone mass

24. BMD and age

25. Changes in BMD with age Peak bone density Menopause Osteopenia Puberty Osteoporosis Age

26. BMD and definition of “osteoporosis” Gaussian distribution Constant standard deviation Decrease with advancing age T-scorei = (BMDi – Peak BMD) / SD • Define “osteoporosis” and “osteopenia” • T-score < -2.5 = “osteoporosis” • -2.5 < T-scores < -1 = “osteopenia”

27. Prevalence of osteoporosis Women Men

28. Bone mineral density (BMD) and fracture risk T < 2.5 osteoporosis Source: Dubbo Osteoporosis Epidemiology Study

29. 14-year predictive value of BMD - women 1287women Osteoporosis 345 (27%) Non-osteoporosis 942 (73%) Fx = 137 (40%) No Fx = 208 (60%) Fx = 191 (20%) No Fx = 751 (80%) 42% Source: Dubbo Osteoporosis Epidemiology Study

30. 14-year predictive value of BMD - men 821 men Osteoporosis N = 90 (11%) Non-osteoporosis 731 (89%) Fx = 27 (30%) No Fx = 63 (70%) Fx = 91 (12%) No Fx = 640 (88%) 23% Source: Dubbo Osteoporosis Epidemiology Study

31. Fracture and BMD: summary of points • BMD is the primary predictor of fracture risk • Less than 50% of fractured individuals have low BMD (eg osteoporosis) • BMD alone does not accurately predict fracture

32. Falls: etiology and risk factors

33. Falls • The second leading cause of accidental deaths (Rivara NEJM 1997) • $70 bil health care costs associated with falls and rehabilitation

34. Incidence of falls in the elderly Source: Dubbo Osteoporosis Epidemiology Study

35. Incidence of multiple falls in the elderly Source: Dubbo Osteoporosis Epidemiology Study

36. Why do falls occur ? Intrinsic Factors Extrinsic Factors Medical conditions Impaired vision and hearing Age related changes Medications Improper use of assistive devices Environment FALLS

37. Etiology of falls • Accidents / environment 37% • Weakness, balance, gait 12% • Drop attack 11% • Dizziness or vertigo 8% • Orthostatic hypotension 5% • Acute illness, medications, vision 18% • Unknown 8% Rubenstein et al JAGS 1988

38. Risk factors for falls • Risk Factor OR • Sedative use 28 • Cognitive Impairment 5 • Lower extremity problem 4 • Pathologic Reflex 3 • Foot Problems 2 • > 3 balance/gait problems 1.4 • >5 balance/gait problems 1.9 Tinetti NEJM 1988

39. Measurement of postural sway A non-fracture control A hip fracture case Postural sway test

40. Predictors of fall risk Note: Odds ratio and 95% confidence interval Source: Dubbo Osteoporosis Epidemiology Study

41. Falls and Fractures

42. Relationship between falls and fractures Falls Fx • 95% of hip fractures are caused by falls (Nyberg L, J Am Geriatr Soc 1996) • Only 5% of falls cause fractures

43. Falls and fracture risk Source: Dubbo Osteoporosis Epidemiology Study

44. Fall-related factors and hip fracture risk Source: Nguyen et al, JBMR 2005

45. Fall-related factors and hip fracture risk BMD-and-gender-adjusted hazards ratio Source: Nguyen et al, JBMR 2005

46. Fall-related factors and hip fracture riskBMD-independent risk factors for hip fracture (*) gender specific ranges Source: Nguyen et al, JBMR 2005

47. Incidence of hip fracture by FNBMD (T-scores) and number of risk factors Source: Nguyen et al, JBMR 2005

48. Predictor of fractures in non-osteoporotic men and women PARF: Population attributable risk fraction Source: Dubbo Osteoporosis Epidemiology Study

49. Can we prevent fracture by reducing falls?

50. Hip protector