In minimally invasive lumbar fusion surgery, your surgeon will make one or more small incisions to insert a tubular retractor to create a tunnel through the muscle and soft tissues to get the area of the spine that is the problem. The tubular retractor stays in place during the entire procedure. Your surgeon uses small instruments that fit through the center of the tubular retractor to remove bits of bone or disk material. Any devices that are needed for the fusion, such as screws or rods, are inserted through the tubular retractor. The operation takes place using fluoroscopy (real-time x-ray images) and an operating microscope which allows the surgeon to magnify the view through the retractor.