OSTEOPOROSIS OSTEOPOROSIS A metabolic bone disorder characterised by
OSTEOPOROSIS
OSTEOPOROSIS A metabolic bone disorder characterised by loss of bone mass, increased bone fragility and an increased risk of fractures. The reduced bone mass is caused by an imbalance of the process that influence bone growth and maintenance. It is a crippling painful bone disease that is the major cause of fractures in post menopausal women
RISK FACTORS Non-modifiable • Gender: more common in females • Age: incidence increases with increasing age • Race: Common in the white race • Genetic factors • Endocrine disorders e. g. hyperthyroidism, hyperparathyroidism, Cushing’s syndrome or diabetes mellitus.
RISK FACTORS CONT’D Modifiable • Oestrogen deficiency: • e. g. after oophrectomy • Prolonged immobility • Insufficient dietary calcium intake • Cigarette smoking • Alcohol intake • Decreased vitamin D • and fluoride levels Medications that decrease calcium retention. E. g. aluminium containing antacids, caffeine, corticosteroids, nicotine and tetracycline Sedentary lifestyle
PATHOPHYSIOLOGY exact pathogenesis of osteoporosis is unclear. it is known to involve an imbalance of the activity of osteoblasts that form new bone and osteoclasts that resorb bone. After peak mass is achieved at the age 35, bone formation does not keep pace with resorption and bone lost is at an average of 0. 7% per year. Three main mechanisms are involved in osteoporosis development: • inadequate peak bone mass (the skeleton develops insufficient mass and strength during growth),
PATHOPHYSIOLOGY Hormonal factors strongly determine the rate of bone resorption; lack of estrogen increases bone resorption as well as decreasing the deposition of new bone that normally takes place in weight-bearing bones. When bone loss exceeds bone formation, bone fracture under common, everyday
PATHOPHYSIOLOGY Although reabsorption affects the entire skeletal system, osteoporosis occurs most commonly in the bones of the spine, hips and wrist. Overtime, wedging, and fractures of the vertebrae produce loss of height, and kyphosis develops. Oestrogen deficiency may increase local production of bone resorbing cytokines such as interleukin-1 and tumour necrosis factor. Oestrogen deficiency also increases sensitivity to the resorptive effects of parathyroid hormone, causing a slight increase in serum calcium levels. By a feedback mechanism, this may decrease vitamin D formation by the kidneys and limit the calcium absorption in the intestines. This leads to
CLINICAL MANIFESTATIONS • • • Loss of height • Dorsal kyphosis and cervical lordosis • develops [“dowager’s hump”] Progressive curvature of the spine • Low back pain Fractures of the forearm, spine or hip Pain which radiates to the flank and abdomen The abdomen tends to protrude and the knees flex as the body attempts to maintain its centre of gravity. Spontaneous fractures
DIAGNOSTIC INVESTIGATIONS • X-rays • Quantitative computed tomography of the spine • Dual-energy X-ray absorpmetry [DEXA] of the lumbar spine or hip • Serum calcium and phosphorus levels estimation • Serum bone gla-protein or osteocalcin • Bone biopsy
MANAGEMENT Medications • Oestrogen replacement therapy • Biphosphonates: e. g. alendronate [fosamax]: these drugs inhibit bone resorption • Raloxifene: is a selective oestrogen receptor modulator • Calcitonin: increases bone formation and decreases bone resorption • Sodium fluoride stimulates osteoblast activity increasing bone formation.
MANAGEMENT Diet • High calcium [e. g. milk, and milk products, sardines, oysters, green leafy vegetables], high vitamin D. High phosphorus, high protein • Calcium and phosphorus supplements Pain Management • Analgesics • Modification of activity tolerance levels • Application of warm compress to the affected joints
MANAGEMENT Prevention of Injury • Implement the necessary safety precautions to prevent injuries • Put patient in a low bed • Use side rails to prevent falls • Encourage client to exercise • Encourage patient to use assistive devices to maintain an independence in activities of daily living
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