Osteoporosis means some of these struts become thin, which makes the bone more fragile and prone to break after a minor bump or fall. These broken bones are often referred to as fragility fractures. Although fractures can occur in different parts of the body, the wrist, hip and spine are most commonly affected.
Bones contain collagen (protein), calcium salts and other minerals. Each bone is made up of a thick outer shell known as cortical bone and a strong inner mesh of trabecular bone which looks like a honeycomb. Bone is alive and constantly changing throughout life. Old, worn out bone is broken down by cells called osteoclasts and replaced by bone building cells called osteoblasts, in a process of renewal called bone turnover. In childhood, osteoblasts work faster enabling the skeleton to increase in density and strength. During this period of rapid bone growth, it takes the skeleton just two years to completely renew itself. In adults the process takes seven to ten years.
Bones stop growing in length between the ages of 16 and 18, but bone density continues to increase slowly until a person is in their mid 20s. At this point the balance between bone demolition and bone construction stays stable. After the age of 35, bone loss increases very gradually as part of the natural ageing process. This bone loss becomes more rapid in women for several years following the menopause and can lead to osteoporosis and an increased risk of broken bones, especially in later life.
Consequences of osteoporosis
Having osteoporosis does not automatically mean that your bones will break, it just means that you have a ‘greater risk of fracture’. Thin, fragile bones in themselves are not painful but the broken bones that can result, can cause pain and other problems. Osteoporosis does not generally slow or stop the healing process. Bones that break because of osteoporosis will still heal in the same way as they do in people who do not have osteoporosis, which is usually about six to eight weeks.
Part of the body most commonly affected
Broken wrists can be the first indication that you have osteoporosis. They often occur in middle aged women who have put out their arm to break a fall. Healthy bones should be able to withstand a fall from standing height so a bone that breaks in these circumstances is known as a fragility fracture.
Hips broken because of osteoporosis occur most commonly in our late 70s or 80s. They happen as a result of a fall and can affect all aspects of life. Full recovery is always possible but will often depend on how well someone is before the broken hip occurs. Getting back to being fully mobile and independent can be difficult and physiotherapy and social care services are often essential. Breaking a hip when you are older can have a major impact on your independence. This can create a real fear of falling among older people which makes them cautious of everyday activities.
Fractures due to osteoporosis of the bones in the spine (vertebrae) usually occur in the lower back (lumbar) or upper area (thoracic) of the spine. They are often referred to as spinal or vertebral fractures. Bones become squashed or compressed because of their reduced strength. Sometimes they are referred to as ‘crushed’, ‘collapsed' or ‘wedged’ depending on how the bone is affected. A ‘compression fracture’ is a good way of describing what happens.
These fractures do not interfere with the spinal cord or result in paralysis or loss of sensation except in very unusual cases. Although bones heal they do not return to their previous shape which can mean height loss or spinal curvature.
If a number of wedge fractures occur together then the spine can tip forward causing an outward curve (kyphosis). If the bones are flattened the trunk can be shortened in length causing loss of height. A fracture of one or more of the vertebrae can occur as the result of an awkward movement, such as reaching up to get something from a kitchen cupboard or lifting heavy shopping bags. Sometimes, they may occur spontaneously, with very little cause, such as following an episode of coughing or sneezing.
If compression fractures are numerous and severe they can lead to significant height loss and curvature causing shortness of breath, protruding stomach, indigestion problems and stress incontinence because of a reduction in the available space for the internal organs.
However not everyone is affected severely and even if you, or someone close to you is, many things can be done to help.
Other bones such as ribs may break if they are fragile but the wrist, spinal bones and hip are most common places for fractures to happen.
Can osteoporosis be prevented?
Our genes decide the potential height and strength of our skeleton but the way we live our life can also play a part in the amount of bone we invest in our bone ‘bank’ during our youth and how much we save in later life.
During childhood, adolescence and early adulthood, when the skeleton is growing, it is vitally important to maximise bone strength. By ‘banking’ plenty of bone in these years, it puts the skeleton in a better position to hold out against the natural bone loss that occurs later in life. You can do this by taking plenty of weight bearing exercise and eating a well balanced, calcium-rich diet.
Can fragility fractures be prevented?
The older we get, the greater our risk of breaking a bone. Osteoporosis becomes more common as the density of bone decreases and bones become generally less strong and more fragile. Falling is also much more common because of poor balance and co-ordination leading to a higher risk of breaking a hip. Lifestyle changes and keeping active can help to prevent falling. Drug treatments, to strengthen bones, are available for those at highest risk of fracture.