At last there is an upside to America's expanding backsides. Cartilage is the thin, hard, flexible coating that gives major joints the strength and protection they need.
Surgeons have few options for repairing damaged cartilage.
Recent studies also show that stem cells in the bone marrow, which have the potential to form into any bodily cells, might also be used. They can produce cartilage under certain conditions. Guilak, director of orthopaedic research at Duke University in Durham, N.C., gets fat cells by liposuction and can harvest about a billion of the specific cells he wants from about two ounces of human fat. And we can always take another couple of ounces. Barbara D. Boyan, PhD, is director of orthopaedic research at the University of Texas Health Science Center, in San Antonio.