Degenerative spinal disorders represent a spectrum of disorders resulting in neurological compromise and symptoms.
These affect the entire spine predominantly the mobile spine segments -- the cervical and lumbar spine. Various conditions include disc prolapse, canal stenosis, spondylolisthesis.
1. Disc prolapse -- One of the most common causes of neurological symptoms. In this condition, there is prolapse of disc fragment resulting in compression of the nerves. The presentation depends upon the level and location of the disc prolapse. Cervical disc prolapse can cause radiculopathy or myelopathy whereas lumbar disc causes radiculoapthy. Large lumbar disc prolapse can also affect the cauda equina roots causing bladder and bowel involvement. Dorsal spine disc prolapse are rare entity presenting with radiculopathy or myelopathy.
Discectomy is performed to remove the prolapsed disc fragments. This can be achieved by microscopic and endoscopic methods. These offer better illumination and magnification thereby improving safety. The target pathology is directly approached without dissection of the normal soft tissues thereby reducing morbidity and allowing for early return to activity. Special retractors and tubular access channels are available that enable these approaches. Multiple levels can also be treated through the same small minimal incisions.
2. Canal stenosis: In this condition, there is reduction in the diameter of the spinal canal due to increase in the thickness of normal tissues as ligamentum flavum and facets. This compromises the neural elements resulting in neurological symptoms such as myelopathy and neurogenic claudication. Surgery includes conventional laminectomy and minimal invasive approaches. Minimal invasive approaches include limited bony resection, excision of hypertrophied ligamentum flavum and undercutting of hypertrophied facets. Multiple levels can be decompressed using these methods. In addition, bilateral decompression can be done from one side using "over-the-top" decompression.
3.Spondylolisthesis: degenerative spondylolisthesis is one of the common disorders affecting the elderly population. Most of these are single or two level listhesis. These patients require decompression of nerves and spinal fixation in the same sitting to achieve complete recovery. Both these can be achieved using minimally invasive (key-hole) methods. Special screws (percutaneous) and rods are available that can be inserted through small incisions. There is minimal muscle dissection and good neurological and pain outcomes.
Degenerative spinal disorders affect the entire spectrum of population. Predominantly, it affects the elderly age group. Minimally invasive surgical methods are better tolerated in this age group, allowing for faster recovery and lesser post-operative complications. Some of the patients with high risk for general anaesthesia have been operated under local / regional anaesthesia with good outcomes.