Cervical ligamentum flavum ossification
Introduction
Introduction to ossification of the cervical ligamentum flavum Cervical ligamentum flavum ossification refers to a type of disease in which a series of symptoms are caused by repeated damage involving the cervical ligamentum flavum and a responsive process of repairing the ligament. This is a senile disease, with a higher proportion in the 50-60 age group, and the incidence rate increases with age. The majority of patients are male, the ratio of male to female is 2:1. The ossification of the ligamentum flavum is common in the middle and lower cervical vertebrae, with the neck 5~6 being the most, followed by the neck 4~5 and the neck 6~7, and the lesion range is mostly 1~ Two vertebrae, multi-segment ligamentum flavum ossification is very rare, in the same segment, the incidence of lesions on both sides and unilateral lesions are similar. Unilateral lesions are more common on the left side. basic knowledge The proportion of illness: 0.03% Susceptible people: no specific people Mode of infection: non-infectious Complications:
Cause
Causes of ossification of the cervical ligamentum flavum
(1) Causes of the disease
The cause of ossification of the ligamentum flavum is still unclear. It is generally considered to be closely related to many factors such as local mechanical factors, metabolic abnormalities, and family heredity. Various factors that increase the abnormal load on the bone attachment of the ligamentum flavum may cause ligament damage. Repeated damage involvement and reactive repair processes will lead to ossification of the ligament.
As with the incidence of ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum is common in Japan, Southeast Asia, and other areas with high sugar content such as rice, and people with diabetes. Glucose metabolism and other systemic conditions, many scholars suggest that ossification of the ligamentum flavum is actually part of the ossification of the spinal ligament, it has also been suggested that the disease and genetic factors, such as the HLA antigen system, ethnic differences are related, because there is a case of identical The twins also have ligaments of the ligamentum flavum and ossification of the posterior longitudinal ligament.
(two) pathogenesis
Ossification of ligamentum flavum
The ossification of the ligamentum flavum begins at the inner edge of the vertebral plate and the medial aspect of the superior articular process, and gradually develops upward, forward and midline, and forward development can also cause so-called hyperostosis of pedicle Histopathological studies have shown that the ossification of the ligamentum flavum is mainly cartilage osteogenesis. In the early stage of the disease, the fibrous structure is disordered, the collagen fibers are significantly proliferated, and the elastic fibers are extremely reduced. In the swollen collagen fibers, there are many fibrocartilage cells. And a large number of island ossification, ossification in the trabecular bone, bone marrow cavity and Harvard tube, under normal circumstances, the vascular ligament of the ligamentum flavum exists in the midline of the edge of the lamina and the anterior part of the superior articular process, in the bone When the foci are being formed, a large amount of vascular tissue can be found at the edge.
Calcification and ossification of the ligamentum flavum
Some scholars have found that cartilage metaplasia and endochondral ossification in the ligamentum flavum of the ligamentum flavum, so the calcification and ossification of the ligamentum flavum are considered to be different stages in the same pathological process, but most scholars believe that the ligamentum calcification and ossification of the ligamentum flavum It is a very different pathological process. The thickness of the ligamentum flavum is obviously increased when it is calcified. It contains bone-like or lime-like nodules. The light microscopy is the deposition of calcium salt in the fibrous or cartilage matrix. There are more calcifications around the calcification. Multinucleated giant cells, tissue cells, lymphocytic infiltration, granuloma-like foreign body reaction, and ossification of the ligamentum flavum characterized by trabecular bone and bone marrow structure are completely different. X-ray diffraction analysis of calcification is found. Mineral crystals such as hydroxyapatite, calcium pyrophosphate, and calcium phosphate.
Cervical ligamentum ligament
The ossification of the ligamentum flavum of the cervical vertebrae forms nodular processes, causing osseous spinal stenosis caused by ligamentous lesions. The ossification of the interlabomelia and the joint capsule of the ligamentum flavum causes stenosis of the central canal or nerve root canal, respectively. The central part of the tube and the nerve root canal are both stenotic, compressing the local cervical spinal cord and nerve roots, and the spinal nerves are congested, edematous, the diameter is thinner, the demyelination and other pathological changes, the damage of the nervous system, except for the local repeated In addition to mild compression, it is also associated with long-standing mild microcirculatory disorders.
Prevention
Cervical ligamentum ligament prevention
The cause of ossification of the ligamentum flavum is still unclear, so there are no effective preventive measures.
(1) The height of the pillow: The physiological lordosis of the cervical vertebra is the basis for maintaining the internal and external balance of the spinal canal under normal conditions. If the pillow or pillow is too low, the neck will be excessively reclined, which can increase the lordosis of the cervical vertebrae. The muscles in front of the vertebral body and the anterior longitudinal ligament are fatigued due to excessive tension, forming a chronic injury; and the ligamentum flavum behind the spinal canal Flexion protrudes into the spinal canal; at this time, although the spinal canal is elongated but the volume is small, the spinal cord and nerve root are prone to clinical symptoms due to various factors such as nucleus pulposus, osteophytes and other factors. If the pillow is too high, the neck is excessively flexed, and it is easy to cause the muscles and ligaments, supraspinous ligaments, interspinous strips, and ligamentum flavum in the posterior cervical spine. The posterior wall of the dural sac in the cervical canal is tightened and forward. Displacement, squeezing the spinal cord, especially the anterior central artery of the spinal cord.
Prominent and prolapsed nucleus pulposus and epiphysis, especially in patients with spinal stenosis, will have corresponding symptoms and signs. The pillow height of patients with cervical spondylosis must be appropriate. Can not be too high or too low, should be based on the principle of sleeping on the pillow without twisting the neck, so that the cervical spine maintains a normal physiological state, preventing or accelerating the degeneration of the cervical vertebra. Generally, the height of the pillow is suitable for the diameter of the pillow, and the head of the pillow is suitable for the lower part of the head. For different conditions of cervical spondylosis, adjust the height of the pillow appropriately. For cervical disc nucleus pulposus nucleus prolapse or protrusion, or vertebral body posterior margin epiphysis, such as direct compression of the spinal cord and motor dysfunction, the pillow can be lower to reduce the pressure of the pressure in front of the spinal canal. For the hypertrophy, invagination of the ligamentum flavum, and the compression of the back of the spinal cord, the pillow may be higher to reduce the compression of the spinal cord. For patients with congenital and acquired cervical spinal canal stenosis with vertebral posterior marginal hyperosteogeny, cervical tuberculosis, cervical spondylosis, and ankylosing spondylitis, the pillow is still at normal height.
It is recommended that people with poor cervical vertebrae choose to use a hot compression sponge pillow, because the first shape of such a pillow conforms to the normal physiological curve of the human body, so that the supine, lateral, cervical vertebrae, and respiratory tract recover normal normal physiological curve while sleeping, and its support Because of the high-temperature hot-compression special sponge, it is the most suitable among all kinds of pillows. It is the most suitable for ergonomics and combined with the magnetic therapy of NdFeB magnetic ore. Trinity and more Helps to improve cervical spondylosis.
(2) Pillow: Commonly used are wheat, puff, kapok, rice husk, duck down, chicken feather, goose feather, slow rebound sponge core, hot compression sponge pillow and so on. The first seven kinds of fillings are light in weight and good in air permeability, but the puff is easy to agglomerate; the price of kapok and duck down is higher; the rice husk is mainly produced in the south, with high hardness and wide production area, and the height of the pillow can be adjusted at will. What kind of pillow filling should be used according to personal habits, economic conditions and under the guidance of a doctor. The ideal pillow for protection against cervical spondylosis should be a thermocompressed sponge core. This pillow is a special pillow with special functions. It is mainly used for cervical spondylosis, cervical hyperplasia, snoring and insomnia. use. This kind of pillow core is made of high-quality sponge through integral measurement and electronic control integrated cutting, especially at high temperature using special thermal compression processing technology and zero pressure testing technology to form special hot compression sponge.
(3) The shape of the pillow: the B shape with the middle low and the two ends is the best. The advantage is that the physiological curvature of the cervical vertebra is maintained by the middle part, and the high part of the head can fix and brake the head and neck.
Complication
Cervical ligamentum ligament complication Complications
Intermittent, chronic, progressive, spastic quadriplegia can occur.
(1) Upper limb symptoms: mainly weakened muscle strength on one or both sides of the hand or arm, and numbness and hand movement flexibility are reduced. In severe cases, the pen holding chopsticks or pinching small items cannot be taken; the patient's grip strength Most of them are declining, and the muscles are moderately or slightly atrophied, especially in large and small fish. It can be found that there is pain disorder during the examination; the Hoffman sign is mostly positive.
(2) Lower extremity symptoms: mainly manifested as difficulty in lifting the lower limbs, mopping the ground or gait trepidation, and feeling the cotton. The adductor tendon is clearly seen as a scissor gait. At the same time, there may be numbness, weakness and sputum in the lower limbs. Those who are severely unable to sit up and turn over themselves are completely squatted on the bed. Increased muscle tone of the lower extremities, hyperreflexia or active, positive for sputum sputum, positive for pathological reflexes, deep sensation and shallow sensation.
(3) Other symptoms: mainly urinary sphincter dysfunction, manifested as dysuria or urinary incontinence; defecation function is also low, every 3 to 5 days, often constipation and bloating. The patient's chest and abdomen may have a sensation of a belt, and it is easy to detect the abdominal wall reflection of the pain dysfunction and the cremaster reflex is weakened or disappeared.
Symptom
Symptoms of ossification of the ligamentum flavum in the cervical spine Common symptoms Ligament ossified spinal cord compression spinal cord compression neck pain fatigue reflex hyperthyroidism sensory head and neck activity restricted
Cervical ligamentum flavum ossification is clinically manifested as spinal cord compression caused by cervical spinal stenosis. Most patients suffer from limb pain, numbness, and numbness of the upper limbs and fingers. When the symptoms are aggravated, limb swelling, fatigue, stiffness, The activity is not flexible, accompanied by neck pain, stiffness, limited mobility, soreness and other symptoms; some patients may have a chest sensation, the lower extremity muscle strength has different degrees of decline, the walking is unstable, the patient describes when walking Step on the cotton-like feeling; severe cases may have dysfunction of the bowel and dysfunction; when the spinal cord is compressed, the patient may have symptoms of pyramidal tract, hyperreflexia, increased muscle tone, convulsions, convulsions, etc., pathology Positive reflexes, etc., the performance of sensory disturbances are not the same, there may be flat sensory disturbance of the spinal cord segment, regional sensory disturbance of nerve root distribution and brown-sequard syndrome.
Examine
Examination of ossification of the cervical ligamentum flavum
Because the clinical manifestations of this disease often have the same performance as cervical spondylosis and cervical spinal stenosis, and are not characteristic, the diagnosis mainly depends on imaging examination.
X-ray film
The ossified shadow of the ligamentum flavum on the X-ray plain film often overlaps with the vertebral body image and is difficult to distinguish. On the lateral X-ray film, there is a density of ossified block shadow between the ventral lamina or lamina, and the lower edge is located next. On the upper edge of the vertebral lamina, the upper edge terminates at 1/2 of the lamina, and the shape is often triangular. If the ossification is small or difficult to identify, the tomographic slice can be taken to further confirm the diagnosis.
It is worth noting that ossification of different parts and different ligaments can often be observed on X-ray films. It has been shown in the literature that nearly half of the patients with ossification of the cervical ligamentum flavum have ligament ligaments in different parts of the spine. Such as thoracic ligamentum flavum, ossification of the posterior longitudinal ligament of the cervical spine, etc., in addition, other cervical diseases, such as cervical degenerative changes, developmental spinal stenosis and congenital cervical deformity, can be observed.
Myelography showed complete obstruction or incomplete obstruction consistent with ossification level. The source of compression of incomplete obstruction often seen on X-ray films was from the posterior of the dural sac.
2. CT examination
CT examination can clearly show that the CT value of the agglomerated ossification in the ventral side of the cervical lamina is the same as that of the bone, and it can be seen protruding into the spinal canal and compressing the cervical spinal cord. For example, CT myelography can be seen. The pressure displacement of the capsule is further determined by the degree of compression.
3. MRI examination
MRI examination on the MRI chest 1 and chest 2 weighted sagittal image, thickening, ossified yellow ligament often showed a low signal shadow to the spinal canal, causing cervical dorsal dural sac compression, cervical ligamentum degeneration When thickening, in the chest 1 and chest 2 weighting, the signal is also low signal to the spinal canal, but the two are often different in morphology. The yellow ligament is often multi-segmented, semi-circular, and The ossification is a single-segment triangular shadow, and the degree of compression is more serious.
Some scholars have pointed out that the ossification of the ligamentum flavum has the same bone marrow and adipose tissue as other bone tissues, and it can also show high signal on the chest-weighted image, and there are some ossification of the ligamentum flavum with different signal levels on MRI images. Corresponding pathological and immunohistochemical studies were carried out, and it was found that the area of equal signal intensity on the MRI image was a small blood vessel proliferating in the hypertrophic ligament, which marked the beginning of the ossification.
Although the MRI examination on the cross-sectional image shows that the ossification of the cervical ligamentum is not as clear as the CT examination, it can directly perform sagittal imaging. In addition to showing the degree of compression of the ossification to the spinal cord, it can also reflect the compression of the spinal cord. Signal changes, determine the prognosis of the disease.
Diagnosis
Diagnosis and differentiation of cervical ligamentum flavum ossification
According to the medical history and clinical manifestations, only the spinal cord or mild or severe compression symptoms are manifested. The diagnosis is based on X-ray examination, myelography, CT and MRI.
Compared with ossification of the cervical ligamentum flavum, calcification of the cervical ligamentum flavum is more common, and the two are similar in clinical and imaging findings, and should be identified.
