The purpose of this study is to compare safety and outcomes of the following treatments of lumbar disc herniation: (1) discectomy with posterior dynamic stabilization with those of (2) discectomy alone or (3) discectomy with internal fixation and fusion.

Discectomy with posterior dynamic stabilization is proposed as the most effective treatment to improve range of motion, and to be similarly effective to discectomy alone and discectomy with internal fixation and fusion for other functional outcomes after surgery.

The purpose of this study is to compare outcomes of (1) discectomy with posterior dynamic stabilization with those of (2) discectomy alone or (3) discectomy with internal fixation and fusion.

Study aims are:

1. To demonstrate superiority of discectomy with posterior dynamic stabilization over discectomy alone and discectomy with internal fixation and fusion in range of motion at the operated level;
2. To demonstrate non-inferiority of discectomy with posterior dynamic stabilization compared to discectomy alone and discectomy with internal fixation and fusion in functional outcomes as measured by change in Oswestry Disability Index;
3. To compare radiological, clinical, patient-reported and safety outcomes among the three surgical approaches.

Inclusion Criteria:

• Signed informed consent

• Age between 20 and 60 years inclusive

• Radiographic evidence of single level lumbar disc herniation

• Scheduled for single-level lumbar discectomy with or without fusion or dynamic stabilization

• Preoperative ODI ≥ 30

• Clinical symptoms consistent with lumbar disc herniation determined by history or physical exam:

  • Radicular back or lower extremity pain and/or
  • Decreased muscular strength and/or
  • Abnormal sensation

• Involved disk at the spinal level between L2 and S1

• Failed to gain adequate symptom relief from at least one month of adequate non-operative treatment, except in patients with severe symptoms that require immediate surgery (at surgeon's discretion)

• Absence of significant symptomatic adjacent segment disk herniation

Exclusion Criteria:

• Cauda equine syndrome
• Previous spinal surgery, except previous discectomy at the same segment
• Patients with other lumbar conditions that will, in the opinion of the investigator, interfere with clinical outcomes (e.g. spinal structural deformities, spinal fractures, ankylosing spondylitis, spinal tuberculosis, spinal infection, spinal tumors, symptomatic cervical spinal disease)
• Osteoporosis defined as T-score ≤ -2.5. BMD will be measured by DEXA performed on lumbar spine
• Systemic infection such as AIDS, HIV, and active hepatitis
• Recent history (less than 3 years) of chemical substance dependency or significant psychosocial disturbance, which may impact the outcome or study participation
• Participation in a clinical trial of another investigational drug or device within the past 30 days