The third whorl of your flower is the stamen, your reproductive part. The stamen is made of a thin vertical thread-like structure called a filament topped having a circular or oblong structure called an anther. The anther produces pollen, which could be the male contribution to the reproduction process in plants. But some of the smaller studies conducted over the past two decades show that no sperm is "progressing" and that some doctors have begun to say that it will not lead to pregnancy. Once the cartilage lining begins to thicken and thin, tendons and ligaments must work harder. This can cause swelling and spur formation, called osteophytes.