The term osteoporosis literally means “porous bone”

Osteoporosis is characterised by abnormally low bone mass & defects in bone structure, a condition which renders the bone unusually fragile and greater than normal risk of fracture in a personof that age,sex & race.Bone depletion may be brought about by predominant bone resorption, decreased bone formation or a combination of the two.Bone loss is a natural part of aging. Bone resorption is not particularly increased but bone formation is reduced & fails to keep pace with bone resorption.Age related decreased ability of bone stem cell to differentiate osteoblast is the cause.
Around the menopause & for the next 10 years bone loss normally accelerates to about 3% per year compared with 0.3%during the preceding two decades due to oestrogen deficiency.
With gradual depletion in androgenic hormone men eventually suffer the same bone changes as postmenopausal woman, only this occurs about 15 years later.
Peak bone mass &bone loss are regulated by both genetic & environmental factors.Genetic factors account for upto 80% of the population variance in the peak bone mass & other determinants of fracture risk such as bone turnover & bone size.
Environmental factors such as exercise & calcium intake during growth & adolescence are important in maximising peak bone mass & in regulating the rate of bone loss. Smoking & heavy alcohol intakeis recognised cause of osteoporosis & osteoporotic fracture.
One half of women & two in five men will develop osteoporosis during their life time.Osteoporosis is the underlying cause of approximately 2 million fracture every year.Osteoporosis fracture can affect any bone, but the most common sites are the forearm, spine &hip.
The immediate mortality is about 12% & there is continued increase in mortality of about 20% when compared with age matched controls.
Other causes of osteoporosis
1. Endocrine: Hypogonadism, Hyperthyrodism, Hyperparathyroidism, Cushing syndrome.
2. Inflammatory: Inflammatory bowel disease, Ankylosings-pondylosis,  Rheumatiod arthritis.
3. Drugs: Corticosteroid, Aromatase inhibitor, Thyroxine over replacement, Sedative, Anticonvulsant, Heparin.
4. GIT: Malabsorption, Chronic liver disease.
5. Miscellaneous: Myeloma, Homocystinuria, Anorexia nervosa, Gauchers disease, Poor diet, Low body weight, Immobilisation.
Clinical feature:
Patients with osteoporosis are asymptomatic until fracture occurs. Osteoporotic fracture occur from little or no trauma.Common presentation are
i. Back pain
ii. Increased thoracic  kyphosis
iii. Loss of height
Investigations:
X Ray- Loss of trabeculae, thining of cortex & insufficiency fracture.
DEXA - For assessment of BMD.
To make other cause of osteoporosis & treatment
Alkaline po4ase    Hormone analysis        
S. Calcium    TSH                                                                                                                 
PTH     Vit D3

Prevention
i. Education about the disease.
ii.    Increasing peak bone mass
iii. Adequate level of dietary Ca&vitD
iv. Exposure to sun          
v.    High level of physical activity      
vi. Avoidance of smoking & excessive alcohol                  
vii. BMD for womanwith multiple risk factor.
Treatment
Effective treatment reduce fracture risk 25-50%
i.    Calcitrol-It increases calcium absorption & stimulate function of osteoblast.
ii.    HRT-Taking Oestrogen or combination Oestrogen& Progesterone for 5-10 year.
Risk is thromboembolism, stroke, breast cancer & uterine cancer.
iii. Bisphosphonates:It is the preferred medication for
osteoporosis.They act by
reducing osteoclastic bone resorption.GIT side effects are a bother.
iv. Calcitonin- It has analgesic properties.It requires parenteral/ intranasal administration.
v.    Parathyroid hormone:Drug of choice for severe osteoporosis & those who do not respond to Bisphosphonate.
vi. Denosumab: Comparatively newer drug, is an AbtoRANKL which holdout the promise of an effective new line of treatment for osteoporosis.
Management of fracture:
Femoral neck & other long bone fracture need operative treatment.
Vertebral fractures are painful. Patient needs analgesic, rest & physiotherapy. Spinal orthosis needed for support &pain relief.
Kyphoplasty is used in an attempt to restore vertebral shape when there is significant degree of vertebral collapse &pain.
Vertebroplasty is indicated for painful vertebral fractures which fail to settle with medical management.
Duration of treatment & monitoring:
The response to drug can be assessed by repeating BMD measurement after 2-3 years.
Osteoporotic treatment is generally given for long time (2-5yr), except 1-84PTH, which is given for 24 months.
Osteoporosis is a silent killer.As the average lifespan is increasing & due to sedentary lifestyle patient of osteoporosis is increasing.We have to be very serious of it.n