Adjacent intervertebral disc disorder is damage or deformation of the intervertebral discs adjacent to the intervertebral vertebrae that have undergone spinal fusion surgery. When it worsens, it may lead to diseases such as disc herniation, spinal canal stenosis, and spondylolisthesis. If the symptoms of adjacent disc damage are mild, corsets, rehabilitation and medication may be the treatment of choice, but if the symptoms are severe, surgery may be considered. If symptoms are caused by disc herniation, a discectomy called PED/PELD may be performed, and if the cause is spondylolisthesis, spinal fusion may be selected as the treatment of choice. The Discseel Procedure also is also a treatment that can be applied after spinal fusion surgery. It is designed to repair and regenerate disc deformation without causing the symptoms of adjacent disc disorder to worsen.