This is an observational study to assess clinical outcomes in patients who undergo spinal fusion. Patients who are already scheduled for spinal fusion will enroll in the study. Information about prior therapies will be collected, and then patients will be followed to see how they do after spinal fusion. This study will help researchers better understand the natural course of patients who patients who undergo spinal fusion surgery.

Inclusion Criteria:

• Lumbar DDD
• Candidate for spinal fusion
• Provide written informed consent

Exclusion Criteria:

• Prior lumbar spinal fusion
• Metabolic bone disease
• Morbid obesity
• Systemic infection or active malignancy
• Pregnancy

Patients requiring spinal fusion