The bones that meet at a joint usually do not rub against each other because they are covered by a rubbery material called cartilage. In people with osteoarthritis, the cartilage wears away, and the bones can grind against each other. Sometimes the bones also form spurs.
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View Originalfigure 1Osteoarthritis of the knee
The bones that meet at a joint usually do not rub against each other because they are covered by a rubbery material called cartilage. In people with osteoarthritis, the cartilage wears away, and the bones can grind against each other. Sometimes the bones also form spurs.
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View OriginalAge when symptoms start
Usually after 40
Commonly affected body parts
Neck and lower back
Joint at the base of the thumb
Knuckles in the middle and near the tip of the fingers
Hip
Knee
Joint in the foot, above the heel
Knuckle at the base of the big toe
Less commonly affected body parts
Shoulder
Wrist
Elbow
Knuckles at the base of the fingers
Symptoms
Pain
Stiffness
Crackling or clicking sounds in the joints
Extra bone growth (for example, knuckles that look swollen or knobby)
Decreased range of motion
Problems with the alignment of certain joints
Tenderness to the touch
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