Inclusion Criteria:

• Age > 21.
• Chronic axial low back pain without radicular pain for > six months, not responding to at least three months of non-surgical management under the direction of a physician.
• One or two discs at L5/S1, L4/L5 or L3/L4 with abnormal findings by MRI, including any of the following: loss of disc hydration, loss of disc height, high intensity zone (HIZ), Modic changes at adjacent vertebral endplates, or herniation without nerve root compression.
• Subject states that he/she is willing to undergo lumbar spinal fusion, disc replacement, or other definitive treatment if eventual diagnosis supports such treatment.
• Physician believes that discography is clinically indicated for the purpose of surgical decision-making for the subject.
• Pre-treatment low back pain by numerical rating scale (NRS) score > 4 (measured as average in last 24 hours on a 0-10 scale).
• Pre-treatment Oswestry Disability Index (ODI) > 40 (0 - 100 scale).
• Subject states availability for all study visits.
• Subject is able to understand the risks and benefits of participating in the study and provides written informed consent.

Exclusion Criteria:

• Known osteoporosis or osteopenia, metabolic bone disorder, or history of chronic steroid use (the equivalent of 7.5 milligrams of daily prednisone use for > 6 months).
• Suspected painful disc degeneration (based on clinical examination and MRI findings) outside of L5/S1, L4/L5 or L3/L4 levels.
• MRI shows disc abnormalities (listed in Inclusion Criteria #3) at all 3 lower lumbar discs (L3/L4, L4/L5 and L5/S1).
• Abnormal neurologic exam attributable to lumbar disc disease, herniation, or lumbar stenosis.
• Back, buttock or pelvic pain suspected to be due to spinal stenosis, spinal fractures, infection, cancer, facet arthropathy or other hip or pelvis pathology.
• Schmorl's node or endplate disruption evident on MRI at L5/S1, L4/L5, or L3/L4.
• Medical history, physical examination or radiographic evidence (e.g., disc height too narrow) to suggest that either PD or F.A.D. may not be technically feasible.
• Any previous lumbar spine fusion or disc replacement.
• More than grade 1 spondylolisthesis as assessed by x-ray or MRI.
• Significant clinical comorbidity that may potentially interfere with data collection or follow-up (e.g., dementia, severe comorbid illness).
• Distress and Risk Assessment Method (DRAM) according to the Main et al. criteria showing Zung Depression Scale scores >33 or MSPQ scores >12.

(Note that DRAM consists of the Modified Zung Depression Score and the Modified Somatic Perception Questionnaire.)

• History of major depression, psychosis or somatization disorder, or panic disorder.
• Allergy to any materials used in PD or F.A.D. devices, contrast, lidocaine, or bupivacaine.
• Any evidence of disc or systemic infection.
• Pregnant or child-bearing potential and not currently on adequate birth control method.