OSTEOPOROSIS

          Osteoporosis affects millions of elderly people worldwide and the greatest fear among women living with osteoporosis is bone fracture. Osteoporosis is defined as a decrease in bone mass per unit volume. This is the most common metabolic cause of low back pain. This occurs when bone resorption (breakdown of bone) exceeds bone production.

Why does bone resorption occur?

          Bone resorption, physiologically (normally), occurs if your blood calcium levels are decreased. That is, if calcium in the blood decreases, a type of bone cells called osteoclasts breakdown some parts of the bones to produce calcium, which is then delivered to the blood stream. When bone resorption occurs more often than bone production, this leads to a decrease in bone mass per unit volume, a condition called OSTEOPOROSIS.

          Both the trabecular bone and the cortical bone are thinning due to this abnormality and it is where fractures are more likely to occur. The vertebral bodies of the spine have the greatest relative amount of trabecular bone and are the most likely sites of bone fracture in osteoporotic patients. The distal parts of the radius and the proximal part of the femur are also common sites of fracture in the same person.

TWO MAJOR TYPES OF OSTEOPOROSIS:

          I. Type I Osteoporosis

                    More common in women after menopause because of the decreased estrogen levels.

          II. Type II Osteoporosis

          This is an age related osteoporosis, wherein, it occurs due to inefficient absorption of calcium from the gastrointestinal tract (due to normal aging) and insufficiency in the uptake of Vitamin D can cause thinning of bones.. Exposure to sunlight and Vitamin D are important factors for the optimal absorption of calcium from the GIT.

Other hormonal imbalances such as Cushing's Syndrome can cause osteoporosis.

          The typical patient (Type I) is a postmenopausal woman with low back pain, decrease in height, and often with a degree of lumbar hyperlordosis (swayback) or thoracic hyperkyphosis (hunchback).

          Radiographic images show that the vertebral column has a marked decrease in vertebral body density and numerous compression fractures throughout the thoracic and lumbar spine, though laboratory findings are normal.

          Although the diagnosis of osteoporosis may seem to be obvious, it is necessary for the physician to exclude other pathological conditions that may cause osteoporosis such as Primary or Secondary Malignancy. On radiography alone, osteoporosis cannot be differentiated from OSTEOMALACIA, only metabolic studies and biopsy can determine the source of the abnormality. It is a fact that the incidence of osteomalacia when compared to that of postmenopausal osteoporosis is low.

Noninvasive diagnostic tools such as dual photon absorptiometer is now available in determining osteoporosis. This can identify the degree of bone mass loss in the trabecular bone. This should give the physician enough information to initiate appropriate treatment programs, such as vitamin D, fluoride, calcitonin, estrogen replacement therapy or other hormone supplements.

          Physical Therapy is also important in training patients in proper weight - bearing procedures or exercises, which eventually stimulate new bone formation and decrease the loss of bone by normal metabolic turnover.

          A balanced diet high in calcium is also extremely important.

OTHER CAUSES OF OSTEOPOROSIS:

1. Prolonged bed rest or general inactivity
2. Prolonged casting or splinting (Results in localized osteoporosis)
3. Paralysis
4. Weightlessness (occurs in space travellers)
5. Poor diet: Anorexia Nervosa
6. Alcoholism
7. Bone marrow tumors (such as lymphoma and leukemia)
8. Hyperparathyroidism
9. Hyperthyroidism
10. Increased Adrenocorticotropic Hormone (ACTH) secretion
11. Excessive glucocorticoid secretion (Adrenal Cortex)
12. Estrogen Deficiency

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