Randomized Evaluation of Lumbar Injection Effectiveness and Function

The goal of this clinical trial is to learn whether the Triojection® System is safe and effective for treating symptomatic lumbar radiculopathy (leg pain caused by nerve irritation or compression) resulting from a contained herniated lumbar disc. The study will enroll adults 18 to 75 years of age with a single-level contained lumbar disc herniation who continue to have symptoms despite at least 6 weeks of non-surgical treatment and a previous lumbar spine injection. The main questions it aims to answer are: * Does treatment with the Triojection® System improve leg pain and overall clinical outcomes compared with Selective Nerve Root Block (SNRB) alone? * Is treatment with the Triojection® System safe, as measured by the absence of device- or procedure-related serious adverse events and persistent neurological deficits? Researchers will compare participants who receive Triojection® followed by SNRB with participants who receive SNRB alone to determine whether the investigational treatment provides improved clinical outcomes. Participants will: * Be randomly assigned to receive either Triojection® plus SNRB or SNRB alone. * Complete questionnaires about leg pain, back pain, disability, quality of life, sleep, anxiety, depression, and overall improvement. * Undergo physical and neurological examinations during study follow-up visits. * Have MRI scans performed at selected study visits to evaluate changes in the treated disc. * Attend follow-up visits at 1, 3, 6, 12, 18, and 24 months after treatment. Up to 300 participants will be enrolled at up to 30 investigational sites in the United States and Canada and followed for approximately 24 months after treatment.

Inclusion Criteria: * In order to be eligible to participate in this study, participants must meet all of the following criteria: 1. Age between ≥18 (skeletally mature) - 75 (inclusive) 2. A single contained posterior lumbar disc herniation, at a single level L1-S1, no greater than 30% of the canal size confirmed by radiographic imaging (via MRI/Axial MRI sequence) 3. Has a preoperative leg VAS ≥ 50 /100 mm in worse leg AND worse leg is at least 20mm greater than the other leg 4. The target level herniated disc must have a disc height of at least 33% (1/3) that of the adjacent disc levels, as determined by the investigator 5. The patient must have pain in a dermatomal distribution consistent with their radiographic findings. 6. Presents with leg pain for at least 6 weeks and that has not responded to conservative therapies (e.g., bed rest, physical therapy, medications, transcutaneous electrical nerve stimulation \[TENS\], etc.). 7. Patient must have had a single previous epidural steroid injection or selective nerve root block at the target level with documentation of initial response and recurrence of symptoms (Prior injection must be at least 2 weeks or greater from screening visit) 8. Psychosocially, mentally and physically able to fully comply with the clinical protocol, provide informed consent, and willing to adhere to follow-up schedule and requirements Exclusion Criteria: * Participants who meet any of the following criteria will be excluded from participating in this study: 1. Evidence of a symptomatic lumbar herniation at more than one level confirmed by patient history and radiographic imaging (via MRI) 2. Functional neurological deficit evident during neurological exam such as drop foot, incontinence, intractable pain, loss of bladder or bowel control, or rapidly worsening symptoms 3. Previous spine surgery in the lumbar region involving the index or adjacent level disc as evident on MRI, or instrumented hardware (e.g., total disc replacement, fusion) at any lumbar spine level 4. Earlier spinal procedures in the lumbar region involving the index or adjacent level discs (basal nerve ablation, radiofrequency ablation, MILD procedure) 5. Distal spinal cord compression on CT/MRI 6. Evidence of cauda equina syndrome 7. Structural deformities i.e., 1. ≥ Grade 2 spondylolisthesis (Up to Grade 1 allowed); 2. Severe Spinal canal stenosis; 3. Scoliosis \> 10 degree Cobb Angle; 4. Loss of lumbar lordosis (i.e., flatback-syndrome diagnosis); 5. Hyperlordosis \> 10 degrees; 6. Spinal fracture (at any level); 7. Disc extrusions or sequestered herniation as evident on CT/MRI. 8. Evidence of a lumbar disc herniation with a maximal protrusion of disc material \>4 mm beyond the posterior vertebral body margin, as assessed by screening MRI. 9. Calcified disc fragment as evident on CT/MRI 10. Inaccessible index disc (e.g. due to, overlap of the iliac wings, and/or steep angulation of the L5/S1 disc space.) 11. Participant has a bleeding disorder, medical condition, or is taking medications that would result in elevated risk (e.g., blood clotting) to undergoing the surgical procedure; or any other clinical reasons deemed by the Investigator in which the patient would not be an appropriate candidate for the study. 12. Any evidence of osteomyelitis/discitis at any level 13. Uncontrolled/acute illness 14. Women who are pregnant or planning to become pregnant during follow-up time period. 15. Worker's compensation, injury litigation, disability remuneration. 16. Active participation in another clinical investigation or course of care that may confound the outcome of this study 17. Systemic infection or infection at the procedure site 18. Currently a prisoner 19. Leg pain of non-spinal or unknown etiology 20. Participant has a spinal cord stimulator 21. Diabetes with an HbA1c \> 8.5 22. Severe peripheral neuropathy 23. Active foot ulcer 24. Any known allergy to steroids or SNRB anesthetic 25. Lumbar myelopathy 26. Active malignancy or planned chemotherapy during follow-up time period 27. Body Mass Index \> 35 28. Evidence of chronic low back pain for ≥ 12 months that is non-responsive to conservative therapy 29. Current or recent history (within 90 days of screening) of chemical/alcohol abuse or dependency using standard medical definition of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) code 30. Current or recent history (within 90 days of screening) of Severe anxiety using standard medical definition of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) code 31. Current or recent history (within 90 days of screening) of Major Depressive Disorder using standard medical definition of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) code 32. Any contraindication for MRI (e.g. claustrophobia) 33. Participant has had a previous lumbar discogram 34. Participant has modic changes at the treatment level (Type 3) 35. Participant has a Schmorl's node at the proposed treatment level 36. Participant has opioid medication usage \> 20 MME (morphine milligram equivalent)/day or change in opioid prescription within 60 days of procedure 37. Participant is currently using a Fentanyl patch (at time of screening) 38. Participant has a known G6PD deficiency disorder