Osteoporosis
The human body has more than two hundred bones in total. Together, these bones form the skeleton that supports the entire body. The bones in our body serve to support the body, protect certain areas of the body, and act as attachment points for muscles. They also produce blood cells. Bone tissue consists of organic and inorganic substances. The organic part is called osteoid. Inorganic substances such as calcium and phosphorus are deposited within it, a process known as mineralisation.
Bone tissue is continuously broken down and rebuilt. The cells that break down bone tissue are called osteoclasts, which are rich in enzymes that play a role in bone resorption. Bone formation, in turn, is regulated by a different set of enzymes, found in cells called osteoblasts. These cells have enzymes that build bone tissue by depositing calcium and phosphorus.
Bone formation is governed by the following processes:
- The load placed on the bone.
- Hormones.
- Vitamins (D).
Bone breakdown is governed by:
- Immobilisation of the bone (little to no load).
- Parathyroid hormone.
- Corticosteroids.
- Vitamins (A).
Osteoporosis is a deficiency of bone osteoid. As a result, the bone becomes much more brittle and fractures occur far more easily. Bone volume also decreases, which can lead to, for example, deformities of the spine.
One in four women under the age of sixty has osteoporosis. By the age of eighty, half of all women have the condition. In men, it is fairly rare.
Symptoms
Because of the structural changes in the bone, it can become, in effect, compressed. In the spine, this can lead to a loss of height of as much as several centimetres. This loss can cause other nearby structures to become pinched. A rounded, hunched back is often seen in this group of patients; this curvature is known as kyphosis. A common accompanying problem is that the person can suffer a bone fracture very easily, particularly in the vertebrae and the hips — sometimes from no more than a minor bump against an object or a relatively gentle fall. A common fracture is a hip fracture, in which a break occurs in the upper part of the thigh bone. This fracture can leave the patient unable to walk for a long period, during which the legs bear minimal load — which in turn causes the bone tissue to deteriorate even further.
Causes
Osteoporosis has several possible causes:
- During menopause, production of the hormone oestrogen drops away. This is an essential hormone for bone formation.
- Chronic disease processes such as rheumatoid arthritis.
- Long-term use of corticosteroids.
- Immobilisation.
Treatment
Osteoporosis is a condition that cannot be cured; the only thing treatment can achieve is slowing the decline of bone tissue as much as possible.
This can be done in the following ways:
- Supplementing calcium in the body, through diet and through calcium tablets.
- Supplementing vitamin D.
- Supplementing oestrogen (through the contraceptive pill).
- Supplementing sodium chloride, which stimulates the enzymes that build calcium into the bone.
- Physiotherapy treatment.
The therapies above are often combined with physiotherapy treatment, in which the load placed on the body is carefully calibrated.
The load must be neither too low nor too high. The physiotherapist can achieve this by working with the patient on certain forms of exercise at a carefully measured level, and by teaching the patient the correct way to load the body during everyday activities — for example through postural therapy. In more advanced stages of the condition, a particular joint may also be fused. This reduces the patient's risk of fracturing that part of the body.