List the functions of the following elements of a synovial joint: fibrous layer of the capsule, synovial fluid, articular cartilage. Sophie worked cleaning homes for 30 years so she could send her two...

List the functions of the following elements of a synovial joint: fibrous layer of the capsule, synovial fluid, articular cartilage.

Sophie worked cleaning homes for 30 years so she could send her two children to college. Several times, she had been forced to call her employers to tell them she could not come in to work because one of her kneecaps was swollen and painful. What is Sophie’s condition, and what probably caused it?