Intervertebral DXM Gel Injection in Adults With Painful Lumbar Degenerative Disc Disease

Inclusion Criteria: 1. Male or female patient aged between 18 and 55 (inclusive) 2. Discogenic low back pain, confirmed by a history of Low Back Pain, with a minimum of 3 months of continuous pain or 6 months of acute episodes of pain despite the conservative treatment including painkillers and physiotherapy 3. Oswestry Disability Index (ODI) ≥ 30% and ≤ 60%, 4. Painful disc(s) between L1 and S1 represented 1. For cohort 1L: at a single disc level 2. For cohort 2L: at 2 disc levels 3. For cohort 1-2L: at 1 or 2 disc levels 5. Patients with a Zung depression score ≤ 49, Note: Patients with a Zung depression score between ≥ 50 and ≤ 64 may be included if deemed suitable for trial inclusion by the investigator 6. Partial dehydration (grey disc) confirmed by MRI, grade II/III Pfirrmann classification Note: * Pfirrmann Grade I lesions are not contra-indications to recruitment, but can never be the target of any intervention in this trial. Patients featuring grade I disc(s) in conjunction with a grade II/III meet the inclusion criteria for his(her) disc Grade II/III disc to be treated * Pfirrmann Grade IV and V disc lesions are absolute contra-indications for inclusion 7. Female patients of childbearing potential must have a negative urine pregnancy test at screening and use an effective birth control during the follow up period after the injection procedure 8. Patients who are willing and capable of understanding the investigator's explanations, following his instructions and adhering to the follow-up visits according to the study protocol, including a willingness and ability to undergo MRI scanning, 9. Patient giving informed consent to take part in the study Exclusion Criteria: 1. Averted nerve root pain and potential root compression Note: Referred leg pain authorised 2. Presence of posterior bone spurs (osteophytes) 3. Partial or total Modic signal grade 1 at the considered disc level 4. Patients with active systemic infection or infection localized to the site of the proposed implantation. 5. Any conditions not described in the indications for use. 6. Any mental conditions or neuromuscular disease that may generate an unacceptable risk of failure or postoperative complication. 7. Patients with existing disc herniation at the considered level and on adjacent discs 8. Endplate disease, defect or weakness, e.g. Schmorl nodule 9. Vertebral bone abnormalities with active angioma 10. Disc collapse ≥ 15% when disc height is compared to the height of the upper adj…