The FRONTDOOR study involves a selective group of patients of approximately 16.000 per year, that need elective lumbar spine surgery for correction of herniated disc or lumbar spine stenosis. Lumbar spinal cord surgery can be performed safely under general anesthesia (GA) or epidural anesthesia (EA). GA is mostly preferred because of greater patient and physician acceptance and the ability to perform operations of longer duration in the prone position with a safe airway. It is demonstrated that regional anesthesia reduces blood loss. During EA the awake patient can self-position to avoid nerve injury of the brachial plexus and pressure necrosis especially to the face. In addition, the perioperative feed-back of the patient allows precise localisation of the involved nerve root to the surgeon and guarding against injuries. Finally, this technique provides excellent long lasting postoperative analgesia . Proposed disadvantages of EA for this surgery are the inability to immediately assess the neurological function, and affected bladder function.