الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Lumbar disc herniation is the most common cause of sciatica and remains a major health problem being a source of economic loss for the individual and the society. The intervertebral disc is an articulation between two lumbar vertebrae and acts as a shock absorber. The disc is composed of three parts; the cartilaginous endplate, annulus fibrosus and nucleus pulposus. Herniation of the nucleus pulposus is a squeal to disc degeneration and occurs between the radial fissures in the annulus. This is predisposed by certain occupations that require heavy weight lifting, smoking, pregnancy, and prolonged driving of motor car vehicles. Recently, studies indicate that genetic factors can play a role in disc degeneration and herniation. Radiculopathies caused by the herniated nucleus pulposus may be produced by a combination of inflammatory, mechanical and biochemical changes brought about by enzymes as Phospholipase A2 and bioactive molecules found in the nucleus pulposus such as nitric acid and tumor necrosis factor alpha. Back pain is often the earliest symptom of lumbar disc disease nearly always followed by sciatica. Occasionally, sciatica may be the only symptom reported by the patient. In addition patients may complain of paresthesia, numbness, weakness, and rarely with sudden paraplegia and bladder disturbances. Signs include; sciatic list, limitation of spine mobility especially forward flexion, positive neural tension signs reproducing the patients pain and neurological deficits according to the level of disc herniation; muscle weakness, sensory loss and altered reflexes. Magnetic resonance imaging is the most accurate method for the diagnosis for lumbar disc herniatins. However, CT myelogram can be used as alternative methods in case MRI is contraindicated Lumbar disc herniations are mainly treated conservatively using different modalities such NSAIDs, oral steroids, Epidural steroid injection, physical therapy and chiropractic manipulation, in an attempt to reduce the pain. The duration of conservative treatment should be at least 6 weeks. Surgery is only indicated in patients who did not respond to conservative treatment and continued to suffer from pain affecting their daily activities, patients with incapacitating pain, or with severe motor weakness, and in patients with cauda equine syndrome. The gold standard in the surgical treatment of patients with disc herniations, particularly in the presence of sequestrated fragments or associate lateral recess stenosis, is now considered to be microsurgical discectomy. In 1997 Foley and Smith developed Microendoscopic Discectomy (MED), the goal of MED is the same as that of conventional lumbar discectomy; to decompress the affected nerve root. This technique involves the use of the endoscope combined with tubular retractors that are introduced percutaneously over muscle dilators, to create a working channel. MED is believed to be superior to the other percutaneous techniques for combining the standard lumbar microsurgical technique with endoscopic visualization, allowing the surgeon to address free-fragment disc pathology and lateral recess stenosis through an even smaller skin incision with less tissue trauma than open discectomy. With increasing use of the endoscope for spine surgery, the disadvantage of the two-dimensionality of the endoscopic image became obvious. To overcome this problem the tubular retractors were combined with the use of the microscope.
Objectives: The aim of this essay is to review the current concepts in endoscopic lumbar spine surgery regarding; endoscopic anatomy of the spine, applications, advantages, inclusion criteria , exclusion criteria, types of endoscopes and instruments used, surgical techniques, complications and lastly the future of minimal invasive endoscopic lumbar spine surgery.