Study of the Safety and Effectiveness of DIAM™ Spinal Stabilization System Versus Conservative Care

The purpose of this study is to establish the safety and effectiveness of the DIAM™ Spinal Stabilization System in the treatment of moderate single-level lumbar degenerative disc disease.

This pivotal clinical trial is being conducted to evaluate the DIAM™ Spinal Stabilization System for the treatment of single-level moderate lumbar degenerative disc disease. The implant under investigation in this clinical trial is the DIAM Spinal Stabilization System, and the device will be implanted using a posterior surgical approach. Patients in the control group will receive nonoperative treatment.

Eligibility Criteria:
Inclusion Criteria:

Each patient participating in this clinical trial must meet all of the following inclusion criteria:

1. Has moderate low back pain secondary to lumbar degenerative disc disease at a single level from L2 - L5. Low back pain is defined as persistent back pain, with or without radicular pain, with current episode of less than one year duration. Degenerative disc disease is confirmed by patient history, physical examination, and radiographic studies with one or more of the following factors (as measured radiographically by MRI scans or x-rays):

   * Decreased disc height \>2mm, compared to the disc space at the next adjacent (superior or inferior, whichever has greater disc height) spinal level;
   * Scarring/thickening of the ligamentum flavum, annulus fibrosis, or facet joint capsule;
   * Herniated nucleus pulposus.
2. Is 18-70 years of age, inclusive, and is skeletally mature.
3. Has pre-treatment Oswestry score ≥ 30.
4. Has pre-treatment back pain score of ≥ 8 based on the Pre-Treatment Back and Leg Pain Questionnaire (Back Pain Intensity + Back Pain Frequency).
5. Has been treated nonoperatively (e.g. bed rest, physical therapy, medications, TENS, manipulation, and/or spinal injections) for a period of at least 6 weeks and not more than 6 months prior to enrollment in the clinical study.
6. If of child-bearing potential, patient is not pregnant or nursing and agrees not to become pregnant during the study period.
7. Is willing and able to participate in either of the randomized treatments for the duration of the study follow-up period. If the patient is randomized to the investigational group, he/she is willing to undergo surgery and receive the DIAM device. If the patient is randomized to the control group, he/she is willing to undergo all four nonoperative treatments.
8. Is willing and able to comply with the study plan and able to understand and sign the Patient Informed Consent Form.

Exclusion Criteria:

A patient meeting any of the following criteria is to be excluded from this clinical trial:

1. Has disc height loss \> 67% at the involved level, compared to the next adjacent (superior or inferior, whichever has greater disc height) spinal level
2. Has Arachnoiditis.
3. Has a primary diagnosis of a spinal disorder other than degenerative disc disease at the involved level.
4. Requires treatment of degenerative disc disease at more than one lumbar level.
5. Has had all of the following nonoperative treatments (prescribed medications, active physical therapy, spinal injections, and patient education) within the past 6 weeks.
6. Has a sequestered herniated nucleus pulposus.
7. Has had any previous surgery at the involved or adjacent spinal levels (including procedures such as rhizotomy).
8. Has received any intradiskal ablation therapy, such as IDET.
9. Has congenital or iatrogenic posterior element insufficiency (e.g. facet resection, spondylolysis, pars fracture, or Spinal Bifida Occulta).
10. Has back pain (with or without leg, buttock, or groin pain) that is not alleviated in any spinal position.
11. Has a motor deficit of the lower extremity.
12. Has cauda equina syndrome.
13. Has compression of nerve roots with neurogenic bowel (fecal incontinence) or bladder (urinary retention or incontinence) dysfunction.
14. Has been previously diagnosed with clinically significant peripheral neuropathy.
15. Has significant vascular disease causing vascular claudication.
16. Has a medical contraindication that prevents the patient from receiving spinal injections (i.e., allergy to contrast media used to aid in placement of the needle in the epidural space).
17. Has ventral spondylolisthesis with more than 2 mm of translation at the involved level.
18. Has evidence of prior fracture or trauma to the L1, L2, L3, L4, or L5 levels in either compression or burst.
19. Has lumbar scoliosis with a Cobb angle of greater than 15°.
20. Has lumbar kyphosis or flat back syndrome.
21. Has sustained a hip fracture within the last year.
22. Has any of the following (if "Yes" to any of the below risk factors, a lumbar spine DEXA Scan will be required to determine eligibility.):

    1. Previous diagnosis of osteoporosis, osteopenia, or osteomalacia.
    2. Postmenopausal Non-Black female over 60 years of age who weighs less than 140 pounds.
    3. Postmenopausal female who has sustained a non-traumatic hip, spine or wrist fracture.
    4. Male over the age of 60 who has sustained a non-traumatic hip or spine fracture.

    If the level of DEXA T-score is -1.0 or lower (i.e., -1.5, -2.0, etc.), the patient is excluded from the study.
23. Has obesity defined by BMI greater than or equal to 40. (Refer to the BMI Table provided in the CIP.)
24. Has a documented allergy to silicone, polyethylene, titanium, or latex.
25. Has overt or active bacterial infection, either local or systemic, and/or potential for bacteremia.
26. Has a suppressed immune system or has taken steroids at any dose daily for more than one month within the last year (excluding low dose inhalers for the treatment of asthma).
27. Has a history of autoimmune disease.
28. Has presence of active malignancy or prior history of malignancy within the last 5 years (except for basal cell carcinoma of the skin).
29. Has presence or prior history of a spinal malignancy.
30. Has chronic or acute renal and/or hepatic failure or prior history of renal and/or hepatic parenchymal disease.
31. Has any disease (e.g., neuromuscular disease) that would preclude accurate clinical evaluation of the safety and effectiveness of the treatment regimens in this study.
32. Has received treatment with an investigational therapy (device and/or pharmaceutical) within 30 days prior to entering the study or such treatment is planned during the 24 months following enrollment in the study.
33. Has an implantable metal device (e.g., stimulator, pacemaker) and is unable to have an MRI.
34. Is an alcohol and/or drug abuser, as defined by currently undergoing treatment for alcohol and/or drug abuse.
35. Is mentally incompetent. If questionable, obtain psychiatric consult.
36. Has a Waddell Signs of Inorganic Behavior score of 3 or greater.
37. Is a prisoner.