OSTEOARTHRITIS – TYPES
Primary or idiopathic – This is the most common type of Osteoarthritis (the cause is unknown). It can affect knees, hips, spine (lumbar and cervical), joints of finger or big toe.
Secondary – The presence of predisposing factors may lead to osteoarthritis of joints. These may include obesity, injury, overuse of joints, metabolic diseases (Hemochromatosis, Wilson’s disease), endocrine diseases (diabetes, hypothyroidism, hyperparathyroidism), inflammatory joint diseases (rheumatoid arthritis, gout).
The bone ends in a joint are covered by cartilage to facilitate movement and to prevent the bones from rubbing against each other. Factors like repeated trauma, advanced age, obesity may cause wear and tear or degeneration of the cartilage.The bone ends in turn, react to this degeneration (also known as reactive bone formation) by forming bony outgrowths called spurs (which impinge on adjoining sensitive, soft tissues causing pain.) Due to increased friction or rubbing of the bone ends, and consequent degeneration of the cartilage, sometimes a grating sensation known as ‘crepitus’ may also be felt on movement. Later on the synovial membrane within may become thick and grow in joint space in the form of finger-like projections known as villi.