By Barbara Floria and Janice Floyd Durante, Pure Matters???Everyone gets joint pain at some point or another,??? says Ferdinand Liotta, M.D., an orthopedic surgeon with Orthopaedic Associates in Aspen, Colo. ???The usual causes are overusing a joint during exercise or at work, age-related arthritis and sprains or fractures caused by falls or other traumatic injuries.???Becoming familiar with the u