Osteoporosis - Causes, Symptoms And Treatment

Alternative name :- Thin bones

Osteoporosis is a metabolic bone disorder in which the rate of bone resorption accelerates while the rate of bone formation slows, causing a loss of bone mass. Bones affected by this disease lose calcium and phosphate salts and become porous, brittle, and abnormally vulnerable to fractures. Osteoporosis may be primary or secondary to an underlying disease, such as Cushing's syndrome or hyperthyroidism.It primarily affects the weight-bearing vertebrae. Only when the condition is advanced or severe, as in secondary disease, do similar changes occur in the skull, ribs. and long bones. Usually, the femoral heads and pelvic acetabula are selectively affected.

Of those affected by osteoporosis,80% are women. Primary osteoporosis is often called postmenopausal osteoporosis because it most commonly develops in postmenopausal women.

What causes Osteoporosis?

In normal bone, the rates of bone formation and resorption are constant; replacement follows resorption immediately, and the amount of bone replaced equals the amount of bone resorbed. Osteoporosis develops when the remodeling cycle is interrupted, and new bone formation falls behind resorption. When bone is resorbed faster than it forms, the bone becomes less dense.

The cause of primary osteoporosis is unknown, but contributing factors include:

• mild but prolonged negative calcium balance due to inadequate dietary intake of calcium (possibly an important contributing factor)
• declining gonadal and adrenal function
• faulty protein metabolism due to relative or progressive estrogen deficiency (estrogen stimulates osteoblastic activity and limits the osteoclasticstimulating effects of parathyroid hormones)
• sedentary lifestyle.

The many causes or risk factors of secondary osteoporosis include:

• prolonged therapy with steroids or heparin (heparin promotes bone resorption by inhibiting collagen synthesis or enhancing collagen breakdown)
• total immobilization or disuse of a bone (as in hemiplegia)
• alcoholism
• malnutrition
• malabsorption
• scurvy
• lactose intolerance
• endocrine disorders, such as hyperthyroidism, hyperparathyroidism, Cushing's syndrome, diabetes mellitus (plasma calcium and phosphate concentrations are maintained by the endocrine system)
• osteogenesis imperfecta
• Sudeck's atrophy Gocalized to hands and feet, with recurring attacks)
• medications (aluminum-containing antacids, corticosteroids, anticonvulsants)
• cigarette smoking.

There are many other risk factors that have been identified, including:

• history of a fracture after age 50 or in a first-degree relative
• current low bone mass
• being female
• being thin or having a small frame
• advanced age
• family history of osteoporosis
• estrogen deficiency as a result of menopause, especially early or surgically induced
• abnormal absence of menstruation (amenorrhea)
• anorexia nervosa
• low testosterone levels in men

Signs and symptoms of Osteoporosis

Osteoporosis is typically discovered suddenly, such as:

• a postmenopausal woman bends to lift something, hears a snapping sound, then feels a sudden pain in her lower back
• vertebral collapse causes back pain that radiates around the trunk (most common presenting feature) and is aggravated by movement or jarring.

In another common pattern, osteoporosis can develop insidiously, showing:

• increasing deformity, kyphosis, loss of height, decreased exercise tolerance, and a markedly aged appearance
• spontaneous wedge fractures, pathologic fractures of the neck and femur, Colles' fractures of the distal radius after a minor fall, and hip fractures (common as bone is lost from the femoral neck).

Possible complications of osteoporosis include:

• spontaneous fractures as the bones lose volume and become brittle and weak
• shock, hemorrhage, or fat embolism (fatal complications of fractures).

Diagnosis information

Differential diagnosis must exclude other causes of bone loss, especially those affecting the spine, such as metastatic cancer or advanced multiple myeloma. History is the key to identifying the specific cause of osteoporosis. Diagnosis may include:

• dual-energy X-ray absorptiometry (DEXA), the gold standard for measuring bone mass of the extremities, hips, and spine
• X-rays showing typical degeneration in the lower thoracic and lumbar vertebrae (vertebral bodies possibly appearing flattened and denser than normal, with bone mineral loss evident only in later stages)
• computed tomography scan to assess spinal bone loss
• normal serum calcium, phosphorus, and alkaline phosphatase levels and possibly elevated parathyroid hormone level
• bone biopsy showing bone that appears thin and porous but otherwise normal.

Treatment of Osteoporosis

Treatment to control bone loss, pre. vent fractures, and control pain may include:

• physical therapy emphasizing gentie exercise and activity and regular, moderate weight-bearing exercise to slow bone loss and possibly reverse demineralization (the mechanical stress of exercise stimulates bone formation)
• supportive devices such as a back brace
• surgery, if indicated, for pathologic fractures
• selective estrogen receptor modulators (such as Evista) that have been approved by the Food and Drug Administration for postmenopausal women to increase bone density (see HRT and osteoporosis)
• analgesics and local heat to relieve pain.

In addition to selective estrogen receptor modulators, medications to treat osteoporosis include:

• calcium and vitamin D supplements to support normal bone metabolism, except when contraindicated, as with calcium supplements in patients with renal disease
• calcitonin (Calcimar) to reduce bone resorption and slow the decline in bone mass
• bisphosphonates, such as etidronate (Didronel) or alendronate sodium (Fosamax) to increase bone density and restore lost bone (strict dosage precautions required; possible adverse effects, including gastric distress)
• vitamin C, calcium, and protein to support skeletal metabolism (through a balanced diet rich in nutrients).

Other measures include:

• early mobilization after surgery or trauma
• decreased alcohol and tobacco consumption
• careful observation for signs of malabsorption, (fatty stools, chronic diarrhea)
• prompt, effective treatment of the underlying disorder (to prevent secondary osteoporosis).

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Tips to keep bones strong

• Exercise.
• Eat a well-balanced diet with at least 1,000 mg of calcium a day.
• Quit smoking. Smoking makes osteoporosis worse.
• Talk to your doctor about HRT or other medicines to prevent or treat osteoporosis.

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Special considerations and Prevention

• Check the patient's skin daily for redness, warmth, and new sites of pain, which may indicate new fractures. Encourage activity; help the patient walk several times daily. As appropriate, perform passive range-of motion exercises or encourage the patient to perform active exercises. Make sure the patient regularly attends scheduled physical therapy sessions.
• Calcium is essential for building and maintaining healthy bone. Vitamin D , which helps your body absorb calcium, is also essential. To get these and other important nutrients throughout life, make sure to keep an overall healthy, well-balanced diet.
• Impose safety and fall precautions. Keep the bed's side-rails in the raised position. Move the patient gently and carefully at all times. Encourage her to wear comfortable, flat shoes with rubber soles to prevent slipping and falling. Explain to her family and ancillary health care personnel how easilyan osteoporotic patient's bones can fracture.
• Make sure the patient and her family clearly understand the prescribed drug regimen. Tell them how to recognize significant adverse effects and to report them immediately. The patient should also report any new pain sites immediately, especially after trauma, no matter how slight. Advise her to sleep on a firm mattress and avoid excessive bed rest. Make sure she knows how to wear her back brace.
• To help prevent osteoporosis, don't smoke, and avoid drinking excess alcohol.
• Teach the patient good body mechanics - to stoop before lifting anything and to avoid twisting movements and prolonged bending.
• Instruct the female patient taking estrogen about the proper technique for breast self-examination. Tell her to perform this examination at least once per month and to report any lumps immediately. Emphasize the need for regular gynecologic examinations. Tell her to report abnormal bleeding promptly.
• Regular exercise can prevent bone fractures. Exercises where muscles pull on bones cause the bones to retain, and possibly gain, density.