• Pain status change assessed using a visual analogue scale (VAS) for radicular pain intensity.
  

• Functional status change evaluated using the Oswestry Disability Questionnaire.
  
• General health status change determined using the SF-36.
  
• Employment status change examined using a questionnaire developed by the American Academy of Orthopaedic Surgeons (AAOS) and the North American Spine Society (NASS).
  
• Subject global satisfaction post-procedure assessed using a global satisfaction statement.
  
• Change in frequency and type of pain medication use.
  

Chronic back pain is the most common ailment in modern industrial societies. It ranks first among musculoskeletal disorders and is associated with serious financial and social consequences. First line conservative care for treating back pain, which frequently occurs in conjunction with debilitating radicular pain, typically includes one or more trials of bed rest, braces, physical therapy and prescription of opioids or expensive non-steroidal anti-inflammatory drugs (NSAIDs). Even though these are routine therapies, they may not be the optimal solution; opioids may be addictive and patients are likely to develop drug intolerance, NSAIDs have potentially dangerous side effects, and physical therapy may be ineffective. Because chronic back pain and its ineffective treatment are associated with such high societal costs, other methods for treating this disorder effectively have been vigorously pursued.

Plasma disc decompression is based on the principle that inducing a small reduction of volume in a closed hydraulic space, such as an intact (contained herniated) disc, can promote significant relief of pressure, and therefore reduce or eliminate pain. Once intradiscal pressure is relieved, the disc is believed to down-regulate inflammatory mediators, reduce in size, and initiate a healing process, thereby alleviating chemical, mechanical, and neural genesis of discogenic pain. The fluoroscopically guided transforaminal epidural steroid injection technique (also known as selective nerve root injection also known as SNRI) is accepted as a relatively safe, effective technique for treating radicular pain. The SNRI technique delivers a high concentration of corticosteroid to the targeted disc nerve interface; this is thought to decrease pain by reducing the inflammatory process. Past investigation has demonstrated efficacy of SNRI over a sham treatment. As SNRIs for therapeutic use are frequently administered in a series of two or more injections 2-3 weeks apart, the length of time in which patients may ultimately receive pain relief, and the costs associated with multiple injections and the extended recovery period are areas that are not fully understood, nor adequately studied. By contrast, the plasma disc decompression procedure is typically performed only once, with subsequent improvement in patient symptoms.

This study therefore proposes to compare the efficacy of the plasma disc decompression procedure to the standard and usual SNRI series in a patient population who have failed to improve after an initial SNRI injection. Patients will have failed an initial SNRI or epidural steroid injection (ESI). The goal of this study is to better understand the differences between the treatment efficacies and rates of symptom improvement through the first six months between patients receiving a series of at least two selective nerve root injections and those undergoing the one-time plasma disc decompression procedure after failing one SNRI or ESI. In addition, patients will continue to be monitored over the 2-year post-procedure period to assess stability of treatment effect.

Inclusion Criteria:

1. Patient has one symptomatic contained, focal herniated lumbar disc.
2. Patient’s age should be at least 18 years old and no more than 75 years old.
3. Selective nerve root injection or epidural steroid injection for symptomatic herniated disc, received between 3 weeks and six months ago.
4. A VAS score for radicular pain of 50 or greater on a scale of 0 to 100.
5. Radicular pain concordant with image findings (MRI or CT).
6. Disc height greater than 50%.
7. Patient signs informed consent.

Exclusion Criteria:

1. Patient is pregnant, or pregnancy is suspected or planned within the study timeframe.
2. Patient is receiving Worker’s compensation or is in litigation related to back/leg pain.
3. Patient has a cardiac pacemaker, automatic defibrillator, or any peripheral stimulator leads in the lumbar area.
4. Allergy to contrast media or drugs to be used in the intended procedure.
5. Medical co-morbidities that preclude surgical intervention.
6. Patient is receiving anti-psychotic therapy.
7. Patient is a prisoner.
8. Patient is incapable of understanding or responding to the study questionnaires.
9. History of previous spinal surgery at, or directly adjacent to, the level to be treated.
10. Patient is morbidly obese (BMI ≥ 40).
11. Patient is simultaneously participating in another device or drug study related to limb/axial pain.
12. Patient has a spinal fracture, tumor or infection.
13. Radicular pain originating from more than one disc level.
14. Axial (back) pain greater than radicular (leg) pain.
15. Clinical evidence of cauda equina syndrome.
16. Progressive neurologic deficit.
17. Radiological evidence of spondylolisthesis at the level to be treated.
18. Radiological evidence of moderate/severe stenosis at the level to be treated.
19. Evidence of extruded or sequestered disc herniation on magnetic resonance imaging.