ILLUSTRATION: Before and after knee replacement surgery

December 19, 2013 | 3:52 p.m. CST
When a patient goes in for a knee replacement it’s usually because eroded cartilage has made walking painful. There is no cure for this type of arthritis, so doctors insert an artificial knee. The doctor attaches metal alloy caps to the thighbone and shinbone, then places a plastic spacer between the metal caps. The plastic spacer acts as artificial cartilage.

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