A condition known as spinal stenosis is one of the top reasons older Americans seek surgery for lower back pain, and the disorder is expected to grow as the population ages. Some orthopedic doctors are concerned the procedure has gotten more complicated than it needs to be as some surgeons combine traditional stenosis therapy with other procedures that fuse vertebrae. The more complex surgery can be beneficial for some patients, especially those with more than one spinal disorder. But it also raises the cost of treatment and increases the chances of complications, including stroke and death, recent research shows. "We're going to see a lot of this problem," says Nick Shamie, MD, an orthopedic spine surgeon at the UCLA Medical Center in Los Angeles and a spokesman for the American Academy of Orthopaedic Surgeons. Some 1.2 million Americans have lumbar, or lower back, stenosis. That number is expected to more than double to 2.5 million by 2020, Dr. Shamie says.