Invertebral discs are located in the spinal column between successive vertebral bodies. Each disc functions as a shock absorber to cushion the spinal column and ensure smooth synchronous and painless movements of the spine.

Inside the Spine

The disc is made of a gelatinous central portion called the nucleaus puposis and an outer ring of ligaments called the Annulus Fibrosus, which seals the nucleus. The annulus has overlapping radial bands, somewhat similar to the plies of a radial tire, and this allows stresses to be distributed without rupture. The disc thus functions as a hydraulic cylinder. Any tear in the annulus leads to failure of this hydraulic cylinder leading to disc dysfunction.

Factors leading to disc prolapse

Several factors can lead to annular tears and disc prolapse This includes smoking, increased coughing, sitting in a stooped posture, driving, lifting heavy weights etc. Tear in the annulus also leads to leakage from the nuclear material which is toxic to the nerves. The resulting inflammatory response causes a neural irritation with radiating pain in the legs (sciatica). This could be accompanied with numbness and loss of reflex. Surgical intervention may be required to relieve the leg pain.

Classical vs Modern

The classical approach in the yesteryears consisted of a procedure called laminectomy. It involved removal of the entire lamina of the spine for approach to the disc. The resulting surgical scar was long and patients were restricted for 2-3 months. Modern lumbar discectomy termed “micro discectomy” utilizes the operating microscope to allow better visualization of the nerve structures. This means it is minimally invasive- minimizes muscle, ligament and bone disruption and allows faster healing. Patients who undergo a micro discectomy can be discharged with minimal soreness and complete relief from leg pain after an overnight admission and observation. Endoscopic techniques allow the same surgery to be performed through an incision of less than 1 cm in size further minimizing disruption of normal structures

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