Osteoporosis: Definition, Causes, Types and Treatments
Definition
It is a generic term referring to a state of decreased mass per unit volume of a normally mineralized bone due to loss of bone proteins. It is called as silent epidemic and usually remains undetected till the patient sustains a hip, rib or spine fracture.
Most common cause is involutional bone loss in premenopausal age group.
Dexa criteria for osteoporosis as determined by WHO, are BMO of spine and hip of 2-5 50′s or more below the mean for heal thy young women and osteopenia between 1 to 2.5 SD’s or more below the mean.
Causes
Disuse
- Prolonged bed rest or inactivity.
- Prolonged casting or splinting.
- Paralysis, space travel, etc.
Diet
- Calcium, protein, vitamin C low in the diet.
- Chronic alcoholism.
- Anorexia nervosa.
Drugs: Whose prolonged use causes osteoporosis is heparin, methotrexate, ethanol, glucocorticoids, etc.
Idiopathic variety is seen in adolescent and middle aged male population.
Genetic role is seen is osteogenesis imperfecta.
Chronic illness like rheumatoid arthritis, cirrhosis, sarcoidosis, renal tubular acidosis, etc.
Neoplasm like bone marrow tumors (myeloma, lymphoma, leukemia).
Endocrine abnormalities: Hyperparathyroidism, increased levels of glucocorticoids, estrogens, etc.
Criteria for screening: The following group of people needs to be screened:
- All women > 65 years of age
- All men > 70 years of age
- Selected post-menopausal men and women who are 50-69 years with risk factors for fractures.
Types
There are two types of osteoporosis. Type 1 is postmenopausal and type 2 age related shows the features in these two types of osteoporosis.
Clinical Features
Early symptoms: The patient complains of acute pain in middle or low thoracic or high lumbar region. Sudden movement, sitting, sneezing, cough, etc. increases pain. Rest relieves it.
Most common symptom of osteoporosis is back pain secondary to vertebral compression. However, in some cases, fractures of axial skeleton may be seen with trivial trauma. Round type of gibbous due to compression of thoracic vertebrae is commonly seen. Other features of osteoporosis.
Investigation
Radiographs
Radiographs changes seen in the spine are:
- Loss of vertebral height due to symmetric transverse compression.
- Biconcave central compression (Cod fish spine) due to the pressure of the bulging disk into the bodies.
- Anterior wedge compression.
- The bone density of the vertebra is reduced.
Other bones
- Ground glass appearance due to generalized rarefaction.
- Singh’s index is the grading of the trabecula pattern of the neck of femur.
- Metacarpal index, etc.
- Pathological fractures.
Densitometry
Techniques for bone mass measurement-
- Single photon absorptiometry is used to asses, the amount of cortical bone mineral in appendicular skeleton.
- Mineral status of axial skeleton is assessed by dual photon absorptiometry (DEXA) and quantative CT scan.
- Total body neutron activation analysis to determine calcium content to the entire body.
Transiliac bone biopsy: It is an important diagnostic tool in patients of more than 50 years in postmenopausal diseases.
Blood chemistry: Serum calcium, phosphorus and alkaline phosphatase levels are usually normal.
Management of Osteoporosis
Preventing osteoporosis is lot easier than treating it. The treatment plan consists of general measures exercises and drug therapy.
General measures
- High protein and calcium rich diet.
- Rest that is adequate.
- Muscle relaxants and supports like belt, collar, etc. for symptomatic relief of pain.
Exercises
Exercises like walking and light aerobics are beneficial.
- Posture exercise: Wall arch, back bending and wall sliding postural exercises help to improve posture and overcome hunched back.
- Fall prevention is of utmost importance.
- Spinal orthosis when patient is erect and mobile.