An L2-3 sequestered disc herniation means a piece of the internal jelly of the disc (the nucleus) has extruded from the complete through and through tear of the disc wall and is separated from the disc laying as a free fragment in the spinal canal. Your question is excellent and it is most important to understand the answer. If you have read the web site, you will know that the disc has no blood supply and therefore, cannot heal the tear. In other words, the tear is permanent. What is to prevent another fragment from exiting the disc? The answer is nothing will prevent another fragment from extruding. This condition is called a recurrent disc herniation and the odds of it happening are about 10% in the active population.
During the surgery, the surgeon should probe the disc to make sure all the remaining nucleus is still “attached” and there are no further free fragments in the disc space. There are areas within the disc space that cannot be probed, so a loose fragment can be left inadvertently. There is a scar that forms over the tear of the disc, but it is a fraction of the strength of the original intact wall.
Well- your next question should be why not remove all the remaining nucleus to prevent further herniations? There is a two fold answer. First- the nucleus is the shock absorber for the two vertebral bodies it is sandwiched in between. Without the nucleus, there is a higher chance of lower back pain as the cushion is gone. The second problem stems from the cartilaginous end plates that line the bones of the vertebral end plates. These can sheer off without the nucleus buffering the shock of impact. These then become free fragments and if they herniate, much more compression of the nerve root occurs as these are the consistency of hard plastic where the original nucleus is the consistency of crab meat.
Hope this gives you enough information.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.