OSTEOPOROSIS

Osteoporosis is an abnormal reduction in bone tissue mass per unit volume of anatomical bone. It is characterized by decreased bone mass and increased susceptibility to fracture.

WHO operationally defines osteoporosis as bone mass density [BMD] 2.5 or more standard deviation below the mean for young adult.  Ostopenia—BMD of 1 to 2.5 SD

1 out of 8 males and 1 out of 3 females in India suffer from osteoporosis.

Factors- Genetic, Hormonal, Dietary, Environmental

After 30 yrs-slow loss occurs, 0.3% in men and  0.5% in women till menopause

Menopause – till next 10 yrs- Rate of bone loss 3% ,Excessive osteoclastic activity , Loss of retraining effect of gonadal hormones

Age 65-75 yrs- Rate of loss 0.5% , Osteoclastic activity reduces .But, osteoblastic activity also reduces

Men -Phase of rapid bone loss 15-20 yrs later than women

CLASSIFICATION– Primary and  Secondary

Primary osteoporosis is defined as osteoporosis that occurs in an individual who has no endocrinopathy or other disease state that would account for the changes in bone mass

ETIOLOGY:

GENETIC FACTORS

ESTROGEN STATUS: stimulates osteoblasts and inhibits osteoclasts. Deficiency causes –activation of new bone remodelling sites , exaggeration of imbalance between bone formation and resorption.

ENDOCRINE DISORDERS- sex hormones , thyroid hormones , PTH , adrenal steroids

NUTRITIONAL DEFICIENCY : Ca, Vit – D, Vit-C

ALCOHOL AND SMOKING

CHRONIC ILLNESS AND TUMORS

DISUSE  : absence of mechanical stress ,  immobilization of the limb

CLINICAL MANIFESTATIONS; Elderly people, sudden onset of pain , stooped posture, shortened stature , fractures with minimal trauma, vertebral compression fractures , acute pain in low thoracic or high lumbar region, thoracic kyphosis, loss of lumbar lordosis  , decrease in axial height, appendicular fractures, proximal femoral fractures, fracture of distal femur.

RADIOGRAPHIC FINDINGS:

VERTEBRAL COLUMN-increased radiolucency, trabecular alterations thinning,  loss of trabaculae (horizontal ), Vertebral body shape alterations  ,wedge shaped vertebra ,fish vertebra , pancake vertebra ,FISH VERTEBRAE, lower thoracic and lumbar vertebra , Intra-discal pressure from nucleus pulposus is more in centre in these vertebra.

MEASUREMENT OF BONE MASS

BONE MASS DENSITY (BMD)

BMD = bone mineral content (BMC) /volume of  bone being studied

Several techniques are available to measure to measure density:

  1. Dual energy x-ray absorption (DEXA)
  2. Ultrasound

MANAGEMENT OF UNDERLYING DISEASE

RISK FACTOR REDUCTION: educate the patient, cessation of smoking, reduction of falls

NUTRITIONAL RECCOMENDATIONS: calcium : dairy products , green leafy veg. Ca and vit-D supplements, others: vit-K, proteins and calories.

Non-pharmacological- Calcium and vitamin-D supplementation , Fall prevention, Hip protectors , Balance and exercise programs

Pharmacological treatment- Antiresorptive Agents , Calcitonin  , Hormone replacement therapy ,Selective estrogen receptor modulators , Bisphosphonates

Osteoporotic vertebral compression fractures

They present with sudden-onset back pain. For acutely symptomatic fractures, treatment with analgesics is required, including

  1. Nonsteroidal anti-inflammatory agents and/or acetaminophen, sometimes with the addition of a narcotic agent (codeine or oxycodone).
  2. Calcitonin may reduce pain related to acute vertebral compression fracture.
  3. Vertebroplasty or kyphoplasty percutaneous injection of artificial cement (polymethylmethacrylate) into the vertebral body.
  4. Short periods of bed rest may be helpful for pain management, but in general, early mobilization is recommended as it helps prevent further bone loss associated with immobilization.
  5. Occasionally, use of a soft elastic-style brace may facilitate earlier mobilization. Muscle spasms often occur with acute compression fractures and can be treated with muscle relaxants and heat treatments.
  6. Back-strengthening exercises  (paraspinal) may be beneficial.
  7. Heat treatments help relax muscles and reduce the muscular component of discomfort. Various physical modalities, such as US and transcutaneous nerve stimulation, may be beneficial in some patients.