When a molecule has no dipole moment, like CO2, then it is nonpolar. When a molecule has a dipole moment like water, then it is polar. This polarity business is very important. Polar molecules are like little magnets, with a positive end and a negative end, and they interact with each other through magnetic attractions.
Degenerative Joint Disease - Hip (Osteoarthritis) Osteoarthritis or Degenerative Joint Disease is the most common type of arthritis that occurs most commonly in hips, knees, ankles, and foot joints. Osteoarthritis is also known as wear and tear arthritis since the cartilage simply wears out. When cartilage wears away, bone rubs on bone causing severe pain and disability.
Key points. 1  A popliteal cyst, also known as a Bakerâs cyst, is a fluid-filled swelling that causes a lump at the back of the knee. 2  Common causes of a popliteal cyst include damage to the kneeâs cartilage and rheumatoid arthritis.