Safety and effectiveness data will be assessed at baseline and annually through five (5) years postoperatively. Office visits will be scheduled preoperatively, and at 6 weeks, 1, 2, 3, 4, and 5 years postoperatively. Clinical/neurological and radiographic examination will be performed during each office visit. A baseline patient history (including medication usage) will be taken, and concomitant medications will be recorded at each postoperative follow-up visit. In addition, patients will be asked to complete the following questionnaires prior to consultation with their physicians or their staff: Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index (ODI), Numeric Rating Scale (NRS), and SF-36 Health Survey. At the 2-, 3-, 4- and 5-year office visit, patients will also be asked two questions assessing the value of surgery and the overall improvement in the quality of life postoperatively.