Abstract
Hip fractures represent the most severe complication of osteoporosis from the perspectives of the patient, carer, health care system and society. Given the strong association with age, numbers are set to rise significantly in the next few decades despite evidence that the age adjusted rates in some countries are either plateauing or falling. Given the almost invariable need for inpatient admission, hospital administrative data for hip fractures remain a robust measure of number of hip fractures in the community and can be extrapolated to determine the total expected number of clinical fragility fractures from the same population. Both process and outcome standards have now been developed to benchmark clinical quality in the care of patients with hip fractures and fragility fractures at other sites.
1
What is the burden of hip fractures?
Osteoporosis is a skeletal disease characterised by low bone mass and the deterioration of bone microarchitecture resulting in an increase in bone fragility and susceptibility to fracture. It is estimated to affect 200 million women worldwide – approximately one-tenth of women aged 60, one-fifth of women aged 70, two-fifths of women aged 80 and two-thirds of women aged 90 (Kanis J. Assessment of osteoporosis at the primary health-care level. Technical Report. World Health Organization Collaborating Centre for Metabolic Bone Diseases, 2007. University of Sheffield, UK.) The most widely used techniques by far are based on x-ray absorptiometry in bone, particularly dual-energy x-ray absorptiometry (DXA).
Osteoporotic fractures have an immense impact on health and economics with hip fractures contributing the most to the burden. The cost to the US economy is around $17.9 billion per annum, with it being in the UK being £1.7 billion [Sanders 1998 p. 1337] . An estimated 10 million Americans over 50 years old have osteoporosis with there being approximately 1.5 million fragility fractures each year . In addition to this there are another 34 million Americans are at risk. The population risk is similar in the UK with 1 in 2 women aged 50 years having an osteoporosis-related fracture in their remaining lifetime and1 in 5 for men.
2
What is the outcome?
Osteoporotic fragility fractures of the hip and non-hip are an important cause of mortality and morbidity . Mortality from hip fracture is greater in men and increases with age. It is also higher for those with other co-morbidities and those with a poor pre-fracture functional status . The mortality is generally highest immediately after the fracture and decreases over time, with the mortality rate from hip fracture within the first 12 months between 20 and 40%. In the US there are approximately 31,000 excess deaths within 6 months of the 300,000 hip fractures that occur annually in the US. In the UK, the 12 month survival post-hip fracture for men is 63.3% vs 90.0% expected, and for women, 74.9% vs 91.1% expected . It is worth noting that the cause of death is not usually directly attributable to the fracture itself, but to other chronic diseases, which lead both to the fracture and to the reduced life expectancy.
Increased mortality rate after hip fracture can remain for up 10 years after hip fracture, and become further elevated over another five years by a subsequent fracture . Reduced survival was observed following all types of fracture except for minor fractures where mortality was increased only for those of 75 years old or greater. Only 25% of deaths from hip fracture are estimated to be directly due to the fracture or resulting complications such as infection, thromboembolism and subsequent surgery Fig. 1 .
In terms of morbidity, in the US, 7% of survivors of all types of fracture have some degree of permanent disability, and 8% require long-term nursing home care . Hip fractures however contribute most to this, as these patients are prone to developing acute complications such as pressure sores, bronchopneumonia, and urinary tract infections. Less than 20% of hip fracture patients are able to walk independently by 6 months and up to 50% are unable to return to their own home .
2
What is the outcome?
Osteoporotic fragility fractures of the hip and non-hip are an important cause of mortality and morbidity . Mortality from hip fracture is greater in men and increases with age. It is also higher for those with other co-morbidities and those with a poor pre-fracture functional status . The mortality is generally highest immediately after the fracture and decreases over time, with the mortality rate from hip fracture within the first 12 months between 20 and 40%. In the US there are approximately 31,000 excess deaths within 6 months of the 300,000 hip fractures that occur annually in the US. In the UK, the 12 month survival post-hip fracture for men is 63.3% vs 90.0% expected, and for women, 74.9% vs 91.1% expected . It is worth noting that the cause of death is not usually directly attributable to the fracture itself, but to other chronic diseases, which lead both to the fracture and to the reduced life expectancy.
Increased mortality rate after hip fracture can remain for up 10 years after hip fracture, and become further elevated over another five years by a subsequent fracture . Reduced survival was observed following all types of fracture except for minor fractures where mortality was increased only for those of 75 years old or greater. Only 25% of deaths from hip fracture are estimated to be directly due to the fracture or resulting complications such as infection, thromboembolism and subsequent surgery Fig. 1 .
In terms of morbidity, in the US, 7% of survivors of all types of fracture have some degree of permanent disability, and 8% require long-term nursing home care . Hip fractures however contribute most to this, as these patients are prone to developing acute complications such as pressure sores, bronchopneumonia, and urinary tract infections. Less than 20% of hip fracture patients are able to walk independently by 6 months and up to 50% are unable to return to their own home .
3
Developed vs. developing countries: secular and demographic changes
The world population is expected to rise from the 323 million individuals aged 65 years or over, to 1555 million by the year 2050. The ageing population is expected to increase the number of hip fractures occurring among worldwide. The incidence is estimated to rise from 1.66 million in 1990 to 6.26 million in 2050. Assuming a constant age-specific rate of fracture, as the number of over 65s increases from 32 million in 1990 to 69 million in 2050, the number of hip fractures in the US will increase threefold .
Together with the increase in the elderly population and the adoption of westernised lifestyles, the increase in the worldwide burden of osteoporotic fractures in future generations will remain. This will lead to the increase in fracture numbers to be uneven across the globe, with the increase in the elderly population in Latin America and Asia potentially leading to a shift in the geographical distribution of hip fractures, with only a quarter occurring in Europe and North America . The few data for the African continent confirm a marked increase in hip fractures driven increased proportion of elderly in the population .
Over the last few decades, data from Switzerland and Finland suggest that the age-adjusted incidence of hip fracture has declined in the developed world over the last decade despite the projected increase in the ageing population . There are many potential explanations for this: a birth cohort effect, an increase in obesity or better screening and treatment for osteoporosis. This pattern of declining age-adjusted incidence in western populations is supported by further studies reported in a recent systematic review . In the developing world the trend appears different, as the decrease in age-adjusted incidence has not been recorded.
In most populations hip fracture incidence increases exponentially with age. Above 50 years of age, there is a female to male incidence ratio of around two to one, however both the incidence rate and female to male ratio varies dramatically between and across continents Fig. 2 .
Related posts:
Multi-disciplinary care of the patient with acute hip fracture: How to optimise the care for the elderly, traumatised patient at and around the time of the fracture to ensure the best short-term outcome as a foundation for the best long-term outcome
Other non-vertebral fractures
Osteoporosis and fragility fractures: Vertebral fractures
Prevention of incident fractures in patients with prevalent fragility fractures: Current and future approaches
How can you prevent falls and subsequent fractures?
Secondary prevention and estimation of fracture risk
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