2. It commonly affects the knee joint
All races are susceptible
Common in older age groups.
Eighty percent of people are affected by 40 years, but
only 40 percent show symptoms.
It causes varus deformity of the knee in the late stages
More than 50 percent have bilateral OA knee
3. Primarily affecting the articular cartilage.
Increase in water content of the weight bearing articular
cartilage
fibrillation
Enormous pressure on the underlying bone, which causes
hardening (sclerosis) and later glossy (eburnation).
4. Meanwhile, the bone at the margins of the joint
hypertrophies to form a rim of projecting spurs.
Subchondral cyst and sclerosis due to microfractures that
degenerate
Loose flakes of cartilage incite synovial inflammation and
thickening of capsule, leading to deformity and stiffness
of joint.
5. Elderly people- mostly in major joint of lower limb, frequently
bilaterally.
Geographical variation in the joint involved, depending upon
daily activities of population.
Hip joint is commonly affected in population with western
living habit.
Knee joint is affected in Asian living habit.
6. Pain is the earliest symptom, intermittently in the
beginning, constant over month or years, decreases
on walking.
Poorly localized dull aching pain
Minimal tenderness and coarse crepitus can be
elicited.
Swelling is late feature which is due to effusion by
inflammation of synovial tissue.
7. Early morning stiffness, which subsides over
the day after some activity
Minimal effusion may be present.
Osteophytes may be palpable.
Genu varum deformity may be seen in very
advanced cases
