Osteoporosis is a disease of bone which characterized by low bone mass that leads to porosity of bones.

🔻characterised by porus bone – thinning of the cortex and trabaculae

🔻 increase in the risk of fractures – hip ,wrist and spine

Types:

Osteoporosis may be:

•Localised : It is usually due to disuse and is seen as a complication of some other disease.

For example, local immobilization following fracture due to other causes.

• Generalized: Involves the entire skeleton. It may be primary or secondary.

–Primary osteoporosis occurs without any known cause.

These include senile postmenopausal.

-Secondary osteoporosis develops due to a large variety of conditions.

These include endocrine disorders (hyperparathyroidism, hyperthyroidism, etc.),

gastrointestinal disorders (e.g. malabsorption, vitamin D deficiency, malnutrition),

drugs (e.g. corticosteroids),

tumors (multiple myeloma)

reduced physical activity,

hormonal disturbances

and other causes (e.g. immobilization).

Etiology

Age : Peak bone mass is achieved between 25 and 35 years of age and gradually declines from the age of 50 years onwards.

Sex: It is generally seen in elderly and women. Genetic/hereditary factors also play an important role .

Pathogenesis

🔸Ageing-due to decrease in the osteoblastic activity and decrease in the growth factors.

🔸Hormones–decreased estrogen, cytokines like IL-1 and IL-6,which increase the osteoclastic activity.

🔸Decrease in the physical activity

🔸Genetic factors

🔸Nutritional status- low calcium intake

Morphology

Entire skeleton is involved in postmenopausal and senile osteoporosis but certain regions are more severely involved than others.

The involved bones are thin and brittle.

Microscopically, it is composed of the lamellar bone which is discontinuous and has thin trabeculae.

Clinical features

Depend on the bones involved.

Commonly involved areas are vertebral bodies and femoral neck

Loss of bone mass predisposes the bone to fracture which results in bone pain.

Fractures are most common in the vertebra in the thoracic and lumbar region, neck of the femur and Colles’ fracture (fracture of distal radius).

Complications

Femoral neck

• Pulmonary embolism and pneumonia as a complication of fractures of the femoral neck, pelvis or spine.

Vertebral fracture

• When fractures of vertebrae are multiple, it may lead to lumbar lordosis and kyphoscoliosis (forward bending).

Diagnosis

🔸plain X-ray – not reliable till 30-40%of bone mass isn’t lost

🔸Dual energy X-ray absorptiometry and quantitative computed tomography

🔸Bone biopsy

Prevention

Exercise

Appropriate calcium and vit d intake

Agents like bisphosphonates

Source – textbook of pathology for dental students – harsh mohan and pathology preparatory manual for dental students Ramdas Nayak