Ageing
Worldwide, the proportion of people aged over 60 years is growing faster than any other age group [1, 2]. This can be considered a result of both longer life expectancy (decreased death rate) and declining fertility rates [3]. In 2006, it was estimated that 688 million people were 60 years or older, and, by the year of 2050, this age group is expected to increase to 2 billion, becoming larger than the age group of children under the age of 14 years [1].
In Australia, the number of people aged 65 and over is projected to more than double by 2055, when compared to today, with an expected number of 40,000 people aged 100 years and over. Moreover, in the next 40 years, male life expectancy is projected to increase from 91.5 years today to 95.1 years, and female life expectancy from 93.6 years today to 96.6 years [4].
Ageing is a natural consequence of life, a complex, multifactorial process that involves physical, psychological …show more content…
It comprises approximately 80% of the total skeletal tissue mass and is most common in the long bone shafts, or diaphysis, of the body (limbs, appendicular skeleton) [7, 8]. Cortical bone is characterized by a slow turnover rate, with a high resistance to bending and torsion, providing a great compressive strength, which contributes to its protective and mechanical role. It forms a thick shell and surrounds a medullary canal (marrow space). The structural subunits are arranged in osteons, with neurovascular channels known as Haversian systems, which are the transport systems for nutrients. Cortical bone is composed of three layers: periosteal envelope (outer surface), intracortical envelope (middle layer), and endosteal envelope (inner surface). Figure 1 demonstrates the cortical bone in the femoral shaft. Ageing is associated with thinning of the cortex and increased cortical porosity
Worldwide, the proportion of people aged over 60 years is growing faster than any other age group [1, 2]. This can be considered a result of both longer life expectancy (decreased death rate) and declining fertility rates [3]. In 2006, it was estimated that 688 million people were 60 years or older, and, by the year of 2050, this age group is expected to increase to 2 billion, becoming larger than the age group of children under the age of 14 years [1].
In Australia, the number of people aged 65 and over is projected to more than double by 2055, when compared to today, with an expected number of 40,000 people aged 100 years and over. Moreover, in the next 40 years, male life expectancy is projected to increase from 91.5 years today to 95.1 years, and female life expectancy from 93.6 years today to 96.6 years [4].
Ageing is a natural consequence of life, a complex, multifactorial process that involves physical, psychological …show more content…
It comprises approximately 80% of the total skeletal tissue mass and is most common in the long bone shafts, or diaphysis, of the body (limbs, appendicular skeleton) [7, 8]. Cortical bone is characterized by a slow turnover rate, with a high resistance to bending and torsion, providing a great compressive strength, which contributes to its protective and mechanical role. It forms a thick shell and surrounds a medullary canal (marrow space). The structural subunits are arranged in osteons, with neurovascular channels known as Haversian systems, which are the transport systems for nutrients. Cortical bone is composed of three layers: periosteal envelope (outer surface), intracortical envelope (middle layer), and endosteal envelope (inner surface). Figure 1 demonstrates the cortical bone in the femoral shaft. Ageing is associated with thinning of the cortex and increased cortical porosity