It represents another step toward the once seeming sci-fi fantasy of repairing or restoring damaged tissue with stem cells. Last week, physicians at Santa Clara Valley Medical Center, in partnership with Stanford Medicine, successfully completed a surgery injecting millions of stem cells into the spinal cord of a patient who had recently suffered a severe spinal cord injury. The aim is to replace damaged neural connections, restoring mobility. The unidentified patient, who is healing successfully, became one of only a handful of people in the world who have undergone the procedure as part of this clinical trial.