One of the reason spine surgeons try to use less hardware as this usually allows more motion after surgery. We also know that levels of the spine above or below rods and screws begin to breakdown over a period of time. Until there are completely new ways to stabilize the spine less is more for now. I believe using newer implants such as spacers is one of the less invasive options for fusion. Most patients are suffering from spinal stenosis. My younger patients with disc disease seldom need anything but microdiscectomy.