I. Definition of cervical spondylosis and diagnostic principles?
The definition of cervical spondylosis encompasses three basic elements.
(1) degeneration of the cervical disc or degeneration of the intervertebral joints;
(2) Involvement of the surrounding tissue structures;
(3) the presence of corresponding clinical manifestations. These 3 components are interrelated and cannot be separated from each other. Therefore, the following diagnostic principles must be met to establish the diagnosis of cervical spondylosis.
(1) Clinical manifestations (i.e. clinical symptoms and signs) of cervical spondylosis are present;
(2) Imaging shows degenerative changes in the cervical intervertebral discs or intervertebral joints;
(3) the imaging signs can explain the clinical manifestations.
According to this diagnostic principle, two biases in the diagnosis of cervical spondylosis should be avoided.
First, the diagnosis of cervical spondylosis should not be made solely on the basis of the presence of degenerative changes in the cervical spine on the imaging signs. Because 80% of people over 55 years of age have degenerative changes in the cervical spine, but most of them do not have clinical manifestations, it is inappropriate to diagnose cervical spondylosis based on imaging findings alone.
Secondly, the diagnosis should not be made only on the basis of clinical manifestations without the necessary imaging examinations to confirm degenerative changes in the corresponding cervical spine, because there is no basis for the development of cervical spondylosis without degenerative changes in the cervical spine. In addition, many clinical manifestations of cervical spondylosis can also exist in diseases other than cervical spondylosis, for example, numbness and weakness of the upper limbs can be caused by thoracic outlet syndrome; dizziness can also be caused by cerebrovascular disease, hypertensive disease, and otologic disease; spastic incomplete paralysis of the extremities can also be caused by intraspinal occupational disease, spinal cavernous disease, and amyotrophic lateral sclerosis. Therefore, the diagnostic principle emphasizes that imaging signs can explain the clinical manifestations.
Second, the typology of cervical spondylosis?
There is no agreement on the typology of cervical spondylosis at home and abroad. According to the discussion at the 1992 symposium on cervical spondylosis in China, cervical spondylosis was classified from the three basic elements included in the definition of cervical spondylosis, namely, cervical, radicular, spinal cord, vertebral artery, sympathetic and other types according to the different clinical manifestations caused by the involvement of different tissue structures. The basis of each type is as follows.
1, cervical type: there are cervical symptoms and pressure points; the cervical spine has curvature changes and instability on X-ray; other disorders of the neck (such as drop pillow, frozen shoulder, myofasciitis, etc.) should be excluded.
2, nerve root type: there are radicular symptoms and signs consistent with the lesion segment; positive pressure neck test or brachial plexus pull test; imaging is consistent with the clinical manifestations; painful point closure without significant effect; can exclude thoracic outlet syndrome, tennis elbow, carpal tunnel syndrome, elbow tunnel syndrome, frozen shoulder, etc.
3, spinal cord type: there are signs and symptoms of cervical spinal cord damage; imaging has cervical spinal stenosis, cervical degenerative changes; should exclude amyotrophic lateral sclerosis, intra-vertebral canal tumor, spinal cord injury, multiple peripheral neuritis, etc.
4.Vertebral artery type: cervical vertigo, history of sudden collapse, positive spin neck test, cervical segmental instability or crooked vertebral joint hyperplasia on X-ray, mostly accompanied by sympathetic nerve symptoms, ophthalmogenic and otogenic vertigo should be excluded, except for insufficiency of blood supply to vertebral artery segment I and III, intracranial lesions, neurosis, etc. Vertebral arteriogram should be performed to confirm the diagnosis. This type is very controversial and should be further studied.
5, sympathetic type: manifested as dizziness, blurred vision, tinnitus, hand numbness, tachycardia, precordial pain and a series of symptoms of plant nerve disorders, cervical intersegmental instability or degenerative changes on X-ray, vertebral arteriography is not abnormal, and cardiovascular and cerebrovascular diseases should be excluded. The basis of this type is also more controversial.
6, other types: refers to the cervical vertebrae anterior bird’s mouth-like osteophytes compressing the esophagus causing swallowing difficulties and confirmed by barium esophageal fluoroscopy, etc.
Third, the pathogenesis of cervical spondylosis?
The pathogenesis of cervical spondylosis is not well understood. The cervical spine is located between the more fixed thoracic spine and the skull with a certain weight, which is highly mobile and prone to strain. It is generally accepted that the pathogenesis of cervical spondylosis is the result of a combination of factors. Degenerative degeneration of the cervical disc and secondary intervertebral joint degeneration are the basis for the pathogenesis of this disease. In the process of cervical spine degeneration, the intervertebral disc is changed first, and then the intervertebral joints are involved, generally in the order of C5 to C6, C6 to C7, and C4 to C5. According to the current understanding, the pathogenesis of the disease is summarized as follows.
1, mechanical compression theory: divided into two kinds of factors: static compression and dynamic compression. From the static compression factors, intervertebral disc degeneration may begin at the age of 20, and degenerative changes in the cervical intervertebral disc occur after the age of 30, and with its cumulative injury, the degeneration can be aggravated resulting in degeneration, swelling, and fracture of the intervertebral disc’s fibrous ring, resulting in the formation of fissures, leading to disc bulging or protrusion, and the ability of the fibrous ring to resist stretching and other decreases, narrowing the intervertebral space, producing abnormal activity between the vertebral bodies, causing the upper and lower vertebral body These bones and the protruding discs protrude into the spinal canal and compress the spinal cord or nerve roots, producing the corresponding symptoms. Research at Peking University Third Hospital has demonstrated that such compression can also block cerebrospinal fluid circulation, and the spinal cord has been found to be tolerant to chronic compression, for example, spinal cord injury has been shown to occur in animal experiments with a spinal canal encroachment rate of 60% or more. In terms of dynamic compression factors, the spinal cord changes with the change in morphology of the spinal canal in extension and flexion during cervical spine extension and flexion activities. When the cervical spine is flexed, the spinal cord is elongated, the transverse area is reduced, and the spinal cord becomes thinner; when the cervical spine is supinated and extended, the spinal cord is compressed axially and the transverse area increases. In cervical extension, the transverse area of the spinal canal decreases by 11% to 17%, while the transverse area of the spinal cord increases by 9% to 17%. If there are already static compression factors, such as herniated or bulging discs on the ventral side of the spinal cord, bone redundancy at the posterior edge of the vertebral body, and thickened ligamentum flavum on the dorsal side of the spinal cord, combined with dynamic factors, further damage to the spinal cord or nerve roots is caused, so that cervical flexion and extension activities may also be a dynamic factor in spinal cord damage. From this point of view, in the case of particularly severe bone redundancy, the repeated micro trauma caused by excessive cervical spine activity may be more noteworthy than simple compression.
2. Cervical instability: As mentioned above, cervical degeneration causes intersegmental instability of the cervical spine, and the spinal cord rubs repeatedly on the bone flab at the posterior edge of the vertebral body during cervical flexion and extension activities, and the accumulation of micro trauma to the spinal cord leads to pathological damage to the spinal cord. In addition, instability caused by cervical degeneration and increased mobility of the intervertebral joints can cause spasm of the lateral spinal arteries and their branches, and also stimulate the cervical sympathetic nerves to reflexly cause arterial spasm, resulting in poor local blood supply to the spinal cord. The cervical sympathetic nerves are derived from the upper part of the spinal cord, and their terminal nerve fibers are distributed to the head, neck, and upper extremities, as well as to the thoracic and abdominal viscera. The cervical sympathetic nerves are distributed directly to the heart and through the traffic branches to the pharynx. Sympathetic nerves around the internal carotid artery accompany the arterial branches to the eye, and sympathetic nerves around the vertebral artery enter the skull and accompany the vagus artery to the inner ear. Sympathetic nerves also distribute to the spinal membrane, spinal cord, circumferential portion of the annulus fibrosus, and ligaments and joints of the cervical spine. Therefore, cervical instability may stimulate the sympathetic nerves in the neck, causing a series of symptoms of disorders of the vegetative nervous system such as blurred vision, tinnitus, balance disorders, tachycardia or bradycardia, and finger swelling. In clinical practice, many patients with cervical instability can have their symptoms temporarily relieved through measures such as cervical collar braking and bed rest; surgical treatment can have more satisfactory results by removing the degenerated unstable segment with bone graft fusion. This also shows the role of cervical instability in the pathogenesis of cervical spondylosis.
3, cervical spinal cord blood circulation disorders: it was recognized early that blood supply factors may be involved in the pathogenesis of cervical spondylosis. Researchers have noted that the spinal cord flattens and turns white during surgery in the cervical flexion position; they have also found that when a herniated cervical disc compresses the spinal cord, the area of spinal cord damage by compression is basically the same as the area of blood supply to the anterior spinal artery, and speculate that the herniated disc compresses the anterior spinal artery and its branches causing ischemic damage to the spinal cord. When the cervical spine is flexed, the tension of the spinal cord increases, the ventral side of the spinal cord is squeezed by the posterior edge of the vertebral body and becomes flattened, and the anterior and posterior diameters become smaller, while the lateral side of the spinal cord is subjected to indirect stresses that increase the transverse diameter, which may strain the branches of the transverse course of the middle sulcus artery of the spinal cord, causing ischemia in the anterior 2/3 of the spinal cord, including the large part of the gray matter, which compresses the small veins inside it and aggravates the lack of local blood supply. If there is a protruding disc or bone superfluous compression on the ventral side of the spinal cord and a thick yellow ligament extrusion on the dorsal side of the spinal cord, coupled with intersegmental instability of the cervical spine, the cervical spinal cord is affected by the “clamping mechanism” when the cervical spine is extended and flexed, making the local blood supply to the spinal cord more susceptible to interference. In addition, if the cervical spine is unstable, it stimulates the cervical sympathetic nerve and causes arterial vasospasm, which also affects the blood supply to the spinal cord.
In conclusion, the pathogenesis of cervical spondylosis is more complex, and the role of compression and instability in the pathogenesis is more studied, while the factors of impaired spinal cord blood supply may also have some relationship with compression or instability. Through clinical practice, such as discectomy and intervertebral implant fusion in the surgical treatment of cervical spondylosis and enlarged spinal canal plasty, good therapeutic results have been achieved, and the above pathogenesis has received some support. However, there are still many aspects of the pathogenesis of cervical spondylosis that are not well understood and need to be further studied in depth.
IV. Non-surgical treatment of cervical spondylosis
The treatment methods of cervical spondylosis can be divided into two categories: non-surgical treatment and surgical treatment. At present, for the treatment of cervical spondylosis, most medical experts advocate non-surgical treatment, and only a few cases need surgical treatment. Non-surgical treatment is a comprehensive therapy combining Chinese and Western medicine, which includes cervical traction, physical therapy, massage and massage, acupuncture, medication, rest, collar or neck brace and medical sports exercise, etc. One or two to three of these methods can be used according to different situations and applied simultaneously or alternately. They are introduced as follows
1.Massage and massage therapy.
This is one of the methods of treatment of cervical spondylosis in Chinese medicine, and is also a more effective treatment measure for cervical spondylosis. It is the therapeutic effect is to relieve the tension and spasm of the neck and shoulder muscles, restore the cervical spine activities, release the nerve roots and soft tissue adhesions to relieve symptoms, widen the vertebral space, expand the intervertebral foramen, rectify the vertebral body slippage to release the neurovascular stimulation and compression, promote local blood circulation and receive the effect of relaxation and activation, relief of spasm and analgesia. Roughly divided into two categories; one is the traditional massage and tui-na manipulation; the other is the rotational repositioning manipulation and lifting end shaking manipulation. But the treatment of manipulation should be operated under the guidance of an experienced specialist to prevent accidents
2.Cervical spine traction therapy.
This is a more effective and widely used treatment method for cervical spondylosis, this therapy is applicable to all types of cervical spondylosis and effective for early cases. Its therapeutic effect is to limit the cervical spine activities, conducive to tissue congestion, edema decompression; release the neck muscle spasm, thereby reducing the pressure on the intervertebral disc; increase the large vertebral space and intervertebral foramen, so that the nerve root stimulation and compression can be eased, so that the distortion of the vertebral artery between the transverse foramen can be stretched; hold open the embedded small joint synovial membrane; buffer the pressure of the intervertebral disc tissue to the periphery, and is conducive to the outward protrusion of the decongestion of the annulus fibrosus tissue
Traction method: Usually the occipito-mandibular band traction method is used, both seated and horizontal, and intermittent traction is used for mild patients, 1-3 times a day for half an hour to one hour each time. In severe cases, continuous traction is feasible, with 6-8 hours of traction per day. The traction weight can start from 3-4 kg and gradually increase to 5-6 kg. Later, the traction weight and traction time can be adjusted appropriately according to the patient’s gender, age, physical strength, neck muscle development and the patient’s response to traction treatment. Course of treatment: small weight traction 30 times for a course of treatment, if effective, can continue traction 1-2 courses or longer, between two courses of treatment should be rested 7-10 days, traction generally requires mild forward flexion of the neck about 20 degrees, but it is best to the patient’s self-conscious symptoms to reduce the appropriate position, do not need to force a specific position
3.Physiotherapy.
In the treatment of cervical spondylosis, physical therapy can play a variety of roles and is also a more effective and commonly used treatment method. It is generally believed that in the acute stage, the iontophoresis, ultrasound, ultraviolet light or intermittent current are feasible; after the pain is reduced, ultrasound, iodine iontophoresis, induction electricity or other heat therapy is used.
4.Medication.
Drugs in the treatment of the disease, especially Chinese medicine can play a major role in the treatment of the cause, Western medicine is only to relieve symptoms, can choose to apply painkillers, sedatives, vitamins (such as B1, B12, Veloxan), vasodilators, etc., on the relief of symptoms have a certain effect.
5.Warm compresses.
This treatment can improve blood circulation, relieve muscle spasm, eliminate swelling to reduce symptoms and help stabilize the affected vertebrae after manipulative treatment. This method can be used hot towels and hot water bags local external compresses, preferably with Chinese herbal fumigation formula to hot compresses. The local temperature should be maintained at about 50-60 degrees Celsius during treatment, and the hot compress time should be 15-20 minutes each time, twice a day. Too high a temperature or too long a time can cause peripheral vasodilation and aggravate the symptoms. Acute patients with heavy pain symptoms should not be warm compress treatment
6.Bed rest.
Bed rest can reduce the weight bearing of the cervical spine and the tension of its surrounding tissues, so that the nerve compression and reactive edema can be reduced, thus accelerating the relief of symptoms. Because the lower limbs of cervical spondylosis patients are not affected and move freely, so patients and even doctors often ignore the problem of rest, so it is very important to emphasize this point.
7.Functional exercise.
In the acute stage, it is appropriate for the patient to rest when the pain symptoms are heavy, and only after the symptoms are reduced and the displaced affected vertebrae are more stable can the patient start functional exercises for the neck and shoulder and back, and the range of neck activities should be smaller when exercising, and the force should not be too violent.
8.Other.
The treatment of cervical spondylosis also includes closed therapy, acupuncture, electroacupuncture, auricular acupuncture, magnetic therapy, peri-collar and cervical brace protection and other medical measures, which are all effective in improving the symptoms
V. Surgical treatment of cervical spondylosis
Surgery for cervical spondylosis is complicated and involves certain risks, so the indications for surgery should be strictly controlled. If a patient is contraindicated for surgery, surgical treatment is not an option. The pathological mechanism and clinical manifestations of cervical spondylosis are complex, and appropriate surgical methods should be selected according to different conditions.
For all types of cervical spondylosis other than the spinal cord type, non-surgical conservative treatment should be preferred because the vast majority of patients can obtain obvious relief or cure by non-surgical treatment, while surgical treatment is mainly for patients with more serious symptoms, who have recurrent attacks after strict non-surgical conservative treatment is ineffective, or whose efficacy is not consolidated.
(I) Selection of indications for surgery
1, cervical cervical spondylosis requires surgery: in principle, cervical cervical spondylosis does not require surgery, and only in rare cases where long-term non-surgical treatment is ineffective and seriously affects normal life or workers, surgery can be considered. Since orthopedic experts still have some differences in the understanding of cervical cervical spondylosis and myofasciitis of the collar and back muscles, surgery for cervical cervical spondylosis should be very cautious.
2, neurogenic cervical spondylosis requiring surgery: in principle, non-surgical treatment should be taken first for neurogenic cervical spondylosis, and the vast majority of patients do not need surgery. Surgical treatment can be considered for those with one of the following conditions.
(1) Regular and systematic non-surgical treatment does not heal in 3-6 months, or non-surgical treatment is effective but recurrent and severe symptoms affect normal life or workers;
(2) Progressive atrophy of the innervated muscles due to compression and irritation of the nerve roots, or significant muscle paralysis and weakness should be operated as soon as possible;
(3) Those who have obvious symptoms of nerve root irritation, acute severe pain, and serious impact on sleep and normal life should also be operated as soon as possible.
3, spinal cord cervical spondylosis requires surgery: spinal cord cervical spondylosis accounts for 5%-10% of cervical spondylosis, is based on the basic pathology of intervertebral disc degeneration, followed by the formation of a bulge containing vertebral redundancy, which constitutes the main compression of the spinal cord or the blood vessels innervating the spinal cord, resulting in varying degrees of spinal cord dysfunction, causing a serious decline in the quality of life of patients or even life-threatening, is a serious danger to human health. It is a serious health hazard. Since the symptoms of this disease are severe and progressive, and once the diagnosis is delayed, it often develops into irreversible neurological damage, so if the diagnosis is clear, surgery should be actively taken. The indications for surgery are generally considered to be
(1) conservative treatment is ineffective, and the symptoms of respite have increased;
② Spinal cord compression symptoms persist for 6 months or more;
Surgery should also be considered for those with severe early spinal cord dysfunction. The criteria for measuring the effectiveness of surgery are.
(1) whether the spinal cord is completely decompressed, whether the normal intervertebral space height and cervical physiological curvature are restored, and whether the volume and shape of the spinal canal corresponding to the spinal cord are restored;
(ii) whether the operation is the least traumatic and has the least complications;
③Whether there is a better recovery of function and a more lasting curative effect.
4. Cases requiring surgery for vertebral artery cervical spondylosis: Non-surgical conservative treatment should be preferred for most of the cases of vertebral artery cervical spondylosis, while surgery can be considered for those with the following conditions.
(1) Cervical vertigo with a history of sudden collapse, and the non-surgical treatment is ineffective;
(2) The diagnosis of vertebral artery type cervical spondylosis is confirmed by cervical vertebral arteriography or MRI vertebral artery visualization, and the conservative treatment is not effective.
5, sympathetic cervical spondylosis requires surgery: sympathetic cervical spondylosis, the vast majority of conservative treatment can have good results. Only when the symptoms seriously affect the patient’s life, the non-surgical treatment is ineffective, the cervical sympathetic nerve closure or cervical high epidural closure test confirms that the symptoms have been significantly reduced, and it is confirmed that the segmental instability or disc bulge can be considered for surgery. However, since sympathetic cervical spondylosis is difficult to distinguish from neurosis and menopausal syndrome, and some patients may even have psychosomatic factors that exaggerate the symptoms, the indications for surgery should be strictly controlled, and surgical treatment should be very cautious.
6, other types of surgical treatment: other types of cervical spondylosis, such as the protruding bone superfluous to the anterior edge of the vertebral body compression and stimulation of the esophagus caused by swallowing difficulties, by non-surgical treatment is ineffective, the protruding bone superfluous to the anterior edge of the vertebral body can be surgically removed, so as to release the compression of the esophagus.
(B) Choice of surgical method
The aim of surgical treatment is to relieve the compression of the spinal cord while maintaining the stability of the spine. In principle, where the compressor is located, it should be removed and decompressed. Generally speaking, both anterior and posterior cervical decompression are effective, but each patient has its own pathological characteristics, which should be considered when choosing the surgical approach.
1.Anterior cervical spine surgery
At present, the anterior decompression methods commonly used in clinical practice are.
1, anterior cervical decompression and bone graft fusion; many literature reports show that this surgical method can remove the anterior spinal cord compression material through the anterior cervical route, release the spinal cord compression, improve the function of the spinal cord, and achieve the role of stabilizing the cervical spine through bone graft fusion, and most cases can obtain satisfactory results after surgery. Therefore, this surgical method is still popularly used in many places. However, this anterior cervical decompression graft fusion without internal fixation has complications such as slippage and collapse of the graft block leading to cervical physiological curvature reversion and deformity; formation of pseudarthrosis, etc., and requires long time external fixation after surgery. Therefore, the fusion rate and stability of the implant segment are concerned by the clinicians, and the internal fixation surgery is gradually carried out.
2, anterior cervical decompression and internal fixation; although anterior cervical decompression and fusion of bone graft has good effect on cervical spondylosis, the stability of bone graft is poor after slotting and decompression for those who are involved in more than 2 segments at the same time. In addition, the micro-movement between the contact surface of the bone graft and the upper and lower vertebrae can cause the failure of bone graft fusion and the formation of pseudo-joint, which affects the surgical effect. In order to prevent the above situation, Bohler first reported the application of anterior cervical plate in 1964, and the research and application of anterior cervical plate have been increasing since then. Anterior plates are mainly used for 2-3 discectomies plus 1-2 subtotal discectomies with anterior grooving for decompression and bone grafting: many biomechanical experiments and clinical studies have confirmed the significant advantages of anterior cervical plates, such as the ability to directly decompress the spinal cord, provide immediate stability, restore cervical physiological anterior convexity, and increase the fusion rate of bone grafting.
Schulte et al. have done a comparative study of the effects of cervical discectomy without bone grafting, discectomy with bone grafting, and discectomy with bone grafting followed by anterior plate fixation on the stability of the cervical spine, and concluded that bone grafting significantly increased the stability of the cervical spine compared with no bone grafting, and further increased the stability after anterior cervical plate fixation. Kaiser et al. conducted a retrospective study of 540 patients and showed that the fusion rates after anterior cervical decompression fusion with and without anterior cervical plate fixation were 96% and 91% for single- and dual-segment cervical spine, respectively; the fusion rates without anterior plate were 90% and 72%, respectively, with statistically significant differences between the two: their study showed that the application of anterior cervical plate can significantly increase the fusion rate of implants. The anterior cervical fixation system has significant advantages in terms of immediate cervical stabilization, firm fixation of the implant, promotion of implant fusion, more complete surgical decompression, reduced incidence of reoperation, early postoperative mobility, and reduced hospitalization time. Complications related to internal fixation should not be ignored, such as screw loosening and fracture, plate fracture and the risk of injury to the spinal cord when occupying the hole or screwing.
3, anterior decompression plus intervertebral fusion (Cage) implantation; after performing anterior cervical decompression, Cage implantation is a new surgical method for treating cervical spondylosis. Its advantages are.
(1) It avoids the surgical trauma and complications associated with bone extraction from the skeleton;
②The material used is titanium metal, which has no effect on MRI examination;
③Rational design, hollow, columnar, threaded and porous morphology, solves the early braking and late bony fusion required for cervical spine surgery;
④The bracing effect enlarges the sagittal diameter of the spinal canal and increases the stability of the vertebral body, and allows the degenerated spinal canal structure to rapidly restore the original tension stress, thus facilitating the rehabilitation of neural tissue;
⑤ This procedure can reduce the time of external fixation by fixing firmly. However, there are shortcomings such as incomplete decompression and limited intervertebral bracing.
However, the emergence of various anterior plates and intervertebral fusion devices, which are widely used at present, cannot effectively avoid the occurrence of adjacent segmental degeneration while increasing the rate of intervertebral fusion. The greatest advantage of artificial disc replacement is to obtain effective decompression of the narrow gap while reconstructing the motion function of the segment, so that the entire cervical spine kinematic characteristics are as close as possible to the preoperative physiological state, reducing the excessive motion and stress concentration of the adjacent segment caused by the loss of motion function of the fused segment after traditional fusion surgery, thus avoiding the occurrence or development of adjacent segment degeneration, and enabling the full release of neural compression while reconstructing the motion function of the spine. The ideal of reestablishing spinal motion while adequately relieving neural compression becomes a reality. However, its clinical application is still very short, and its potential complications such as sinking of the prosthesis, paravertebral ossification, late fusion, and wear and tear are yet to be verified by long-term clinical studies.
The anterior cervical approach can directly remove the compression factors, such as herniated discs, posterior vertebral margins and hypertrophic posterior longitudinal ligaments, thus achieving complete decompression and helping to restore the natural physiological curvature and sequence of patients with posterior synostosis, mainly for lesions involving one or two disc levels and the presence of posterior synostosis. With the development of anterior cervical surgery techniques, anterior cervical decompression and internal fixation with bone graft fusion are now being clinically promoted. However, for lesions at the level of multiple discs, although anterior cervical surgery can technically achieve decompression, it is difficult to maintain the stability of the cervical spine after surgery, and posterior cervical surgery is still required when necessary.
2.Posterior cervical spine surgery
Posterior surgery is to open the spinal canal and part of the nerve root canal under direct vision, to investigate and clarify the compression of the spinal cord and nerve root by the lesion, and to release the factors of compression, so that the spinal cord and nerve root can have a certain buffer space and achieve the purpose of relative decompression. after the 1970s, Japanese scholars designed a variety of posterior spinal canal enlargement: extensive cervical arch resection, spinal canal enlargement, single-opening spinal canal enlargement, double-opening spinal canal enlargement and so on. These procedures were widely used in the 1980s to treat severe spinal stenosis and OPLL as well as multisegmental spinal cord cervical spondylosis, and satisfactory results were achieved. At present, the posterior procedures are generally laminoplasty and laminectomy. It has been suggested that postoperative cervical biomechanical structure is better with laminoplasty than with laminectomy, thus preventing postoperative disruption of the cervical physiological arc and cervical instability. However, a controlled retrospective 5-year follow-up study by Hukuda et al. did not confirm the superiority of laminoplasty over laminectomy in the treatment of spinal cervical spondylolisthesis.
However, it is generally believed that laminectomy alone is prone to epidural blood accumulation, adhesions, and focal scars, which can re-compress the spinal cord at a later stage and affect the surgical outcome. Laminoplasty is simple, safer than laminectomy, and has less bleeding. The disadvantage is that closing the door again after shaping can cause recurrent stenosis. Some scholars have improved the technique by using bone implant fixation at the opening or lead fixation technique of the opening lamina to effectively avoid the reclosure phenomenon. In posterior laminoplasty, there are single-opening, double-opening, and Z-laminoplasty, but the basic principle is that the spinal cord is displaced dorsally by expanding the cervical spinal canal to achieve relief of spinal cord compression. In vertebroplasty, a new single-opening laminoplasty has recently emerged, which is different in that it reveals unilaterally, preserves the integrity of the spinous process, supraspinous ligament and interspinous ligament, and lifts the lamina to the opposite side, causing a fracture of the contralateral lamina and achieving the purpose of enlarging the spinal canal.
Cervical spondylosis with spinal stenosis is now more common. In such patients, the compression factors of the spinal cord are not only from the anterior degenerated and protruding disc tissue, posterior bony redundancy and/or ossified posterior longitudinal ligament, but also from the posterior thickened lamina and ligamentum flavum, etc., which are often involved in multiple segments. The ultimate goal is to achieve definite long-term results. However, posterior surgery cannot remove the ventral compression of the spinal cord, and can only play an indirect role in decompression, so the indications for surgery should be strictly controlled.
3. Combined anterior and posterior surgery
For the treatment of severe spinal cord cervical spondylosis, the anterior-posterior approach is traditionally used in two stages, which is often not easily accepted by patients due to the disadvantages of long treatment period, high cost and great pain. In 1995, Mcafee et al. reported that the combined anterior-posterior surgery with simultaneous anterior decompression, bone graft fusion and subsequent posterior internal fixation in 100 cases of cervical spinal cord compression caused by various factors such as trauma, tumor and degeneration had achieved satisfactory results. There is still a big controversy about the sequence of anterior and posterior surgery. Some scholars believe that the anterior decompression and fixation surgery should be performed first, followed by posterior canal enlargement surgery. This is because the decompression of the spinal canal and the stability of the spine after the anterior surgery are more complete and reliable than the posterior surgery, which provides a guarantee for the safety of the posterior surgery; the posterior enlargement of the spinal canal is likely to lead to the failure of the opening of the spinal canal when it is moved from the prone to the supine position after the posterior surgery or during the anterior surgery. However, most scholars believe that the posterior decompression first gives the spinal cord a posterior cushion space, and then the anterior surgery can reduce the trauma to the cervical medulla, and then the posterior decompression can be taken when the neck is lying down, which also creates conditions for the exposure of the anterior approach.
One-stage combined anterior and posterior surgery saves the patient from secondary surgery, and also has the advantages of complete decompression, satisfactory efficacy, shortened treatment period, and reduced medical costs. However, the operation is a big blow, especially for elderly patients with high morbidity. Most of these patients are in poor physical condition and may have potential lesions of major organ functions in varying degrees, and their surgery is poorly tolerated and prone to systemic multisystemic complications. Moreover, the postoperative cervical spine is less stable, and when biomechanical evaluation of simultaneous anterior and posterior decompression was performed, some scholars found that severe posterior extension instability of the cervical spine occurs. Therefore, not every patient is suitable for this procedure. In addition to carefully selecting the indications for surgery, it is also necessary to actively adopt a perioperative management plan to effectively avoid complications.
4.Posterior one-time surgery
For the treatment of cervical stenosis combined with cervical disc herniation, simple anterior or posterior surgery often cannot achieve the treatment purpose, such as combined anterior and posterior surgery, which not only increases the difficulty and risk of surgery, but also increases the trauma and pain of patients. Yoshi-no reported that the JOA scores of 30 patients increased from 3.5-15 (mean, 11.4) preoperatively to 9-17 (mean, 15.2) postoperatively with a single posterior cervical laminoplasty and microscopic removal of the intervertebral disc through the epidural approach, and noted that this procedure It was noted that this approach could avoid the ruptured intraventricular plexus bleeding caused by the transdural approach. However, the anatomical relationship of this approach is complex, and the operation is in direct contact with the spinal cord, which makes the operation difficult and risky, and its anatomical basis has not been reported yet.
Subsequently, Zhang Tao, a domestic scholar, reported the application of transvertebral discotomy and suction on the basis of single-opening enlargement of the spinal canal or hemi-vertebroplasty in the treatment of cervical spinal stenosis combined with disc herniation, supplementing the posterior one-time surgery method. Gao Dianhua reported the use of posterior transcervical hemi-laminoplasty with collagenase injection to achieve a one-time treatment with ideal therapeutic results. This method does not require special instruments and excessive enlargement of the spinal canal, does not require excessive stretching of the cervical spinal cord and nerve roots, and is easier and safer to operate. However, it should be noted that when injecting collagenase, damage to the posterior venous plexus and dura mater should be avoided, and injection of the drug into the venous plexus and subarachnoid space should be prevented to avoid serious complications, and collagenase may cause allergic reactions. The one-time surgery via posterior cervical approach is based on the enlargement of the cervical spinal canal and laminoplasty to remove the soft compression in front of the spinal cord, while relieving the anterior and posterior compression of the spinal cord, which not only reduces the trauma and pain of the patient, but also relatively reduces the occurrence of complications. However, its indications are narrower, and it is not effective for posterior vertebral body bones and ossified posterior longitudinal ligaments, and there is even the possibility of damaging the spinal cord.