Lumbar Discectomy Control Study, Risk Factors for Reherniation

The purpose of this 12-month, prospective, multicenter study is to investigate the effect of annular defect size and other risk factors on reherniation and associated costs in primary lumbar discectomy patients.

This study will enroll up to 100 patients at select US (approximately 4-7) sites. Patients that are scheduled for an L1-S1 discectomy and who meet the pre-operative eligibility criteria will be considered for study participation. Patients will be divided into two arms (small- and large-defect) based on the size of their annular defect as measured intra-operatively; each arm will be capped at 50 patients. All patients included in the trial will be followed for at least 12 months.

Eligibility Criteria:
Inclusion Criteria:

1. Age 21 to 75 years old and skeletally mature (male or female).
2. Patients with posterior or posterolateral disc herniations at one level between L1 and S1 with radiographic confirmation of neural compression using MRI. \[Note: Intraoperatively, only patients with an annular defect (post discectomy) between 4mm and 6mm tall and 6mm and 10mm wide shall qualify.\]
3. Radiculopathy (with or without back pain) with a positive Straight Leg Raise (0 - 60 degrees)22 (L45, L5S1) or Femoral Stretch Test (L12, L23, L34)
4. Oswestry Questionnaire score of at least 40/100 at baseline.
5. VAS leg pain (one or both legs) of at least 40/100 at baseline.
6. Psychosocially, mentally and physically able to fully comply with the clinical protocol and willing to adhere to follow-up schedule and requirements.
7. Minimum posterior disc height of 5mm at the index level.

Exclusion Criteria:

1. Spondylolisthesis Grade II or higher (25% slip or greater).
2. Subject requires spinal surgery other than a discectomy (with or without laminotomy) to treat leg/back pain (scar tissue and osteophyte removal is allowed).
3. Subject has back or non-radicular leg pain of unknown etiology.
4. Prior surgery at the index lumbar vertebral level.
5. Subject requiring a spine dual energy x-ray absorptiometry (i.e., patients with SCORE of ≥ 6) with a T Score less than -2.0 at the index level. For patients with a herniation at L5/S1, the average T score of L1-L4 shall be used.
6. Subject has clinically compromised vertebral bodies in the lumbosacral region due to any traumatic, neoplastic, metabolic, or infectious pathology.
7. Subject has sustained pathologic fractures of the vertebra or multiple fractures of the vertebra or hip.
8. Subject has scoliosis of greater than ten (10) degrees (both angular and rotational).
9. Any metabolic bone disease.
10. Subject has an active infection either systemic or local.
11. Subject has cauda equine syndrome or neurogenic bowel/bladder dysfunction.
12. Subject has severe arterial insufficiency of the legs or other peripheral vascular disease. (Screening on physical examination for patients with diminution or absence of dorsalis pedis or posterior tibialis pulses. If diminished or absent by palpation, then an arterial ultrasound is required with vascular plethysmography. If the absolute arterial pressure is below 50mm of Hg at the calf or ankle level, then the patient is to be excluded.)
13. Subject has significant peripheral neuropathy, patient defined as a patient with Type I or Type II diabetes or similar systemic metabolic condition causing decreased sensation in a stocking-like or non-radicular and non-dermatomal distribution in the lower extremities.
14. Subject has insulin-dependent diabetes mellitus.
15. Subject is morbidly obese (defined as a body mass index \>40, or weighs more than 100 lbs over ideal body weight).
16. Subject has been diagnosed with active hepatitis, AIDS, or HIV.
17. Subject has been diagnosed with rheumatoid arthritis or other autoimmune disease.
18. Subject has active tuberculosis or has had tuberculosis in the past three (3) years.
19. Subject has a history of active malignancy: A patient with a history of any invasive malignancy (except non-melanoma skin cancer), unless he/she has been treated with curative intent and there have been no signs or symptoms of the malignancy for at least two (2) years.
20. Subject is immunologically suppressed, received steroids \>1 month over the past year.
21. Currently taking anticoagulants, other than aspirin, unless the patient can be taken off the anticoagulant for surgery.
22. Subject has a current chemical/alcohol dependency or significant psychosocial disturbance.
23. Subject has a life expectancy of less than three (3) years.
24. Subject is currently involved in active spinal litigation.
25. Subject is currently involved in another investigational study.
26. Subject is incarcerated.
27. Patients will be divided into two arms (small- and large-defect) based on the width of their annular defect as measured intra-operatively. Patients with defects \<6mm in width will be in the "small defect" arm; patients with defects ≥6mm in width will be in the "large defect" arm. Each arm will be capped at 50 patients. Once 50 patients are accrued in one arm, subsequent patients who meet the criteria for that arm will be excluded. Enrollment will continue until both arms are filled.