The purpose of this study is to evaluate the effectiveness of two minimal invasive endoscopic discectomy, PTED and MED, for the treatment of symptomatic lumbar disc herniation.

Lumbar disc herniation (LDH) is a common pathological process leading to spinal surgery. Open discectomy used to be a widespread procedure for surgical treatment for symptomatic LDH. Currently, with rapid progress of endoscopic techniques, several minimal invasive endoscopic surgeries have been developed to perform discectomy. Percutaneous transforaminal endoscopic discectomy (PTED) and microendoscopic discectomy (MED) are two widely used minimal invasive surgical procedures, the effectiveness of which has been proved to be comparable to conventional open discectomy. As difference in operative approaches and iatrogenic injury, the clinical outcome might be dramatically different from each other.

In this study, a single center randomized controlled trial will be performed to evaluate the effectiveness of two minimal invasive endoscopic discectomy, PTED and MED, for the treatment of symptomatic LDH. We will conduct the study at the 3rd affiliated hospitals of Sun Yat-Sen University.

Two groups of patients will be investigated; 1) patients diagnosed with lumbar disc herniation undergoing PTED, and 2) patients diagnosed with lumbar disc herniation undergoing MED.

The primary outcomes of the study will be score of Oswestry Disability Index (ODI) as measured at pre- and post-operation, 1 month, 3 months, 6 months, and annually thereafter. Secondary outcomes include Visual Analog Scale (VAS), the SF-36 Health Survey, as well as post-operative radiological assessment. Treatment effect is defined as the difference in the mean change from baseline between the two groups. Lumbar intervertebral disc tissue would be obtained during surgery for histological analysis, in order to evaluate disc degeneration and find out risk factors of it.

On the basis of the results of this trial we will, for the first time, have scientific evidence as to the relative effectiveness of PTED versus MED for minimal invasive surgical treatment for symptomatic lumbar disc herniation.

Inclusion Criteria:

• Persistent radicular pain.
• Signs including evidence of nerve root compression with a positive nerve root tension sign (straight leg raising test or femoral tension sign) or a corresponding sign of neurological deficit (asymmetrical depressed reflex, decreased sensation in a dermatomal distribution, or weakness in a myotomal distribution).
• An imaging study (MRI or CT) showing LDH at a level and side corresponding to the patients radicular signs or symptoms.

Exclusion Criteria:

• <18 or >65 years of age
• Insufficient conservative treatment (6 weeks)
• Cauda equina syndrome or progressive neurologic deficit requiring urgent surgical intervention
• Combination with other spinal disorder requiring advanced surgery (such as lumbar stenosis, spondylolisthesis, deformity, fracture, infection, tumor and so on)
• Equal to or more than two responsible level
• High-grade migrated disc herniation
• Previous spinal surgery
• Possible pregnancy or other comorbid conditions contraindicating surgery