Spine surgery is one of the most common operative procedures in the United States. It is performed in the prone position (a patient laying on belly). Muscle relaxants are given for neuromuscular blockade often referred as paralysis for surgical exposure which is maintained until the patient is returned to the supine position (a patient laying on back) at the end of surgery. At the end of the surgery the paralysis is reversed with a drug (neostigmine). A new drug (sugammadex) has the ability to rapidly reverse the paralysis but it is not well investigated in elderly. This study will investigate speed of recovery and complications of the two reversal drugs in elderly patients (age ≥ 65 years) undergoing posterior spine surgery.