If you have started on prednisone 30mg or greater and expect to be on it for greater than two weeks you may be a candidate for the study. Also, you would need to be enrolled in the study within three days of starting prednisone. If you are eligible you will receive lipitor 40mg per day or pills which look exactly like lipitor but do not contain any medication (called placebo). During the time of the study, you will not know if you are taking lipitor or the placebo. The period of time that you will receive lipitor or placebo is 9 months and you must be willing to return for 5 follow up visits during this time which include blood tests, physical exams and 3 MRI studies of the hips, knees and ankles.