# Laser Reconstruction of Spinal Discs Experiments and Clinic
###### Abstract  
Degenerate disease of the intervertebral discs (DDD) is currently a serious problem facing the world community. The surgical methods and conservative therapy used today, unfortunately, do not stop the pathological process, but serve as a palliative method that temporarily relieves pain and improves the patient's quality of life. Therefore, at present, there is an active search for new methods of treating DDD. Among new techniques of treatment, biological methods, and minimally invasive surgery, including the use of laser radiation, which, depending on the laser parameters, can cause ablative or modifying effects on the disc tissue, have acquired considerable interest. Here, we analyze a new approach to solving the DDD problem: laser tissue modification. This review of publications is focused on the studies of the physicochemical foundations and clinical applications of a new method of laser reconstruction of intervertebral discs. Thermomechanical action of laser radiation modifies tissue and leads to its regeneration as well as to a long-term restoration of disc functions, elimination of pain and the return of patients to normal life.  
laser modification; tissue structure; regeneration; cartilage repair; spine; intervertebral disc; degenerative disc diseases +
Footnote †: journal: Medical  
The NP is the inner part of the IVD; it consists of a highly hydrated tissue of a jelly-like consistency. The basis of the NP is formed by water (80-90%) and large compounds of GAG. The sulfate groups of GAGs carry negative charges that contribute to the maintenance of osmotic pressure in the disc, which ensures the amortization functions of the spine. The amount of cells in the IVD is very low (0.25-0.5%). Cells must maintain the macromolecular structure of the disc, a certain concentration of PG, collagen, proteases, and their inhibitors throughout life. Inside the disc of an adult, blood vessels are completely absent, and nutrition of the cartilaginous structures is carried out from the bodies of the vertebra by diffusion and osmosis through the EP. IVD remains healthy as long as the balance between the synthesis and decay of its macromolecules is maintained.  
At the initial stages of development of DDD, the NP is gradually dehydrated. A decrease in pressure inside the disc produced pathological mobility in the vertebral segment. Clinically, this is manifested by the appearance of local moderate pain in the damaged area, a feeling of fatigue, and recurrent attacks of myogenic pain syndrome. Changes appear in MRI. Losing moisture, NP, normally light and homogeneous, gradually fragments and becomes dark in color. This phenomenon is called a dark disc. The progression of the degenerative process in the IVD, dehydration of the NP, and an increase in segment instability led to a significant increase in the load on the AF. As a result, the number of AF microcracks increases; these microcracks gradually transform into functionally significant cracks and ruptures (Figure 1B). Fragments of the NP begin to penetrate these cracks. With sharp physical exertion, the process can be aggravated to a complete rupture of the AF with the loss of sequestered fragments of the destroyed NP into the spinal column.