Thoracic spinal stenosis refers to a disease in which congenital or acquired degenerative factors lead to compression of the thoracic spinal cord and nerve roots, resulting in corresponding clinical signs and symptoms. Compared with cervical spondylosis, lumbar disc herniation and other spinal degenerative changes, thoracic spinal stenosis is relatively little known to us, but with the advancement of diagnostic imaging technology and the deepening of the understanding of the disease, thoracic spinal stenosis is not uncommon and the ossification of the ligamentum flavum is the most common cause of thoracic spinal stenosis, only that most patients do not show symptoms of spinal cord compression and are not known to clinicians. Ossification of the ligamentum flavum is the most common cause of thoracic spinal stenosis, only that most patients do not show symptoms of spinal cord compression and are not well known to clinicians. Many patients with thoracic spinal stenosis are combined with cervical spondylosis and lumbar spondylosis at the same time, which often leads to misdiagnosis and underdiagnosis, however, the special anatomical and physiological characteristics of the thoracic spinal canal and the thoracic spinal cord result in a high rate of paralysis and a great risk of surgery. Many spine surgeons regard thoracic spine surgery as a forbidden area of surgery. Causes of thoracic spinal stenosis The three most common causes of thoracic spinal stenosis are ossification of the ligamentum flavum, thoracic disc herniation and ossification of the posterior longitudinal ligament, which are both independent of and interrelated with each other. Other rare causes include intraosseous cartilaginous nodules at the posterior margins of the vertebral bodies of the thoracic vertebrae, diffuse idiopathic osteohypertrophy, and fluorosciatic osteomalacia, among others. Ossification of the ligamentum flavum of the thoracic spine (OLF): this is the most common cause of thoracic spinal stenosis, accounting for more than 80-85% of all thoracic spinal stenosis. Although a large number of studies have been carried out, the etiology of the disease is still not very clear, and it is hypothesized that it may be related to stress concentration (thoracolumbar and cervicothoracic segments), degenerative factors, genetic factors, and racial differences (Japanese and Caucasian), and that the disease is often associated with ankylosing spondylitis, diffuse idiopathic osteohypertrophy, and fluorosis. The disease is often associated with ankylosing spondylitis, diffuse idiopathic osteohypertrophy, osteofluorosis, and abnormal calcium and phosphorus metabolism. The disease has an insidious onset and progresses rapidly, with most patients developing the disease before the age of 50. Thoracic disc herniation (TDH): it is the second most common cause of thoracic spinal stenosis, accounting for about 15% of cases, with the vast majority occurring in the lower thoracic spine. Autopsy studies and imaging studies suggest asymptomatic TDH in 11% of cases, and surgical treatment of TDH accounts for approximately 0.2% to 2% of all thoracic and lumbar discectomies performed. Clinical findings show that TDH is often combined with Hugh’s disease, and the disc herniation seen is often calcified, which is mostly seen in young patients; for older patients, TDH is often combined with spinal degenerative factors such as osteophytes at the posterior margin of the thoracic vertebral body and hyperplasia of the calcaneus or hypertrophy of the ligamentum flavum, etc. In addition, studies have shown that the angle of spinal kyphosis is significantly greater than that in normal populations in thoracic and lumbar disc herniations in the corresponding and neighboring segments, which may lead to an increase in the local stress and accelerated disc injury. This may lead to increased localized stress and accelerated disc injury. Ossification of the posterior longitudinal ligament (OPLL): It is relatively rare, accounting for about 5% of cases, but it is the most difficult cause to deal with. OPLL is a common cause of cervical spondylosis in Asians, but it is relatively rare in the thoracic spine because OPLL causes ventral compression of the spinal cord, and thoracic spine protrusion makes it difficult to achieve the effect of spinal cord concessions by traditional posterior decompression, and ossification of posterior longitudinal ligament and dura mater with extensive adhesion also imaging the effect of posterior decompression. The ossification of the posterior longitudinal ligament and the extensive adhesion of the dura mater also implies the effect of posterior decompression. Clinical manifestations of thoracic spinal stenosis The disease is mainly manifested as a series of upper motor neuron damage clinical manifestations of spinal cord compression, insidious onset, gradually aggravated, early only feel after walking for a distance, the lower limbs are weak, stiffness, sinking, inflexible, etc., there is no obvious pain and numbness in the lower limbs, and the lower limbs can continue to walk after resting for a few moments, which is known as spinal cord intermittent claudication, which is similar to that of the common lumbar stenosis, characterized by pain and numbness. This is significantly different from the common neurogenic intermittent claudication in lumbar spinal stenosis, which is mainly characterized by pain and numbness. With the progression of the disease, there is a feeling of stepping on cotton, stiffness in lower limb movement, difficulty in walking, numbness and girdling sensation of the trunk and lower limbs, difficulty in urination and defecation, urinary retention or incontinence, sexual dysfunction, etc., and paralysis can occur in severe cases. A part of patients with compression located in the thoracolumbar segment, manifested as lower motor neuron damage clinical manifestations, such as extensive lower limb muscle atrophy, lower limb weakness, loss of sensation and so on. However, it should be noted that many patients with thoracic spinal stenosis are combined with cervical spondylosis or lumbar degenerative diseases, which often leads to underdiagnosis or misdiagnosis of the disease, because most of the damage to the spinal cord is irreversible, and it is recommended that patients with the above mentioned symptoms should go to the regular specialized hospitals in time, so as to avoid delaying the best time for diagnosis and treatment.