For business reasons / product no longer available from Sponsor

The overall goal of this clinical study is to characterize the fusion rate of geneX® ds bone graft substitute in comparison to autograft, which is considered the gold standard for posterolateral fusion. Assessments are made using AP and Lateral x-rays, F/E x-rays, and CT scans geneX® ds has been cleared by the FDA for use in these procedures; however this study will allow more detailed characterization of geneX® ds performance in the long-term (1 year). By using the patient as their own control, direct comparison to autograft can be performed while minimizing other variables.

Inclusion Criteria:

• Men or women 18-75 years of age
• Have ability to understand the requirements of the study, to provide written informed consent, and to comply with the study protocol
• Have a spinal condition of the lumbar spine (L1-S1) requiring instrumented posterolateral fusion at one or two levels

Exclusion Criteria:

• Patients undergoing instrumented fusion for trauma, tumor, psuedoarthrosis, or same- - level recurrent stenosis
• Patients where placing graft material on both sides (posterolateral gutters) is not possible, for example in the case of a complete facetectomy
• Patients requiring instrumented fusion in the cervical or thoracic spine
• Extraspinal cause of back pain such as trauma, infection, instrumentation failure, or neoplasm
• Severe degenerative bone disease
• Hypercalcemia
• Active local or systemic infection
• Morbid obesity defined as BMI > 40
• Patients who are pregnant / able to become pregnant and not following a reliable contraceptive method
• Uncooperative patients who can't or won't follow post-operative instructions including individuals who abuse drugs or alcohol
• Anatomy or other factors that prohibit safe surgical access to the surgical site
• Allergy or sensitivity to any component of the treatment procedure
• Inadequate tissue coverage over the operative site
• Inadequate bone stock or bone quality
• Fever or leukocytosis
• Uncorrectable coagulopathy or hemorrhagic diathesis
• Uncontrolled diabetes
• Severe vascular disease or cardiopulmonary conditions that present prohibitive anesthesia risk
• Neuromuscular disease or disorder
• Mental illness
• Has an active workman's compensation lawsuit

The subject population will include adult (skeletally mature) men and women with spinal conditions for which instrumented posterolateral fusion (PLF) has been indicated as a course of treatment. Such spinal conditions may include symptomatic degenerative disc disease, spondylolisthesis (Grade I or II), or lumbar stenosis. The study is limited to those patients requiring instrumented PLF at one or two levels only. Subjects who are undergoing other spinal procedures during the same surgery (such as interbody fusions) are also eligible.