The majority of patients with cervical spondylosis have lower cervical spine lesions. Degeneration, stenosis, osteophytes, and instability are common clinical pathological signs that can seriously affect the patient’s daily life, work, and quality of life. Surgery is currently one of the effective treatment methods. The aim of surgery is to regain the normal sequence of the cervical spine and the curvature, height and mobility of the cervical spine, maintain the stability of the cervical spine, and improve the function of bony compressed nerves. With the introduction of various new surgical theories and improvements in spinal internal fixation techniques, clinical surgical methods have been continuously improved. This article reviews the latest advances in various cervical spine surgical approaches at home and abroad in recent years.
1. Anterior surgery
1.1 Anterior fusion
1.1.1 Anterior cervical discectomy fusion (anterior cervical disckectomy fusion, ACDF) In 1986, Morcher et al. first applied anterior cervical plates to anterior cervical spine surgery. The anterior plate provided strong internal fixation with clear and rapid results and a high rate of interbody fusion. Since then, in-depth studies have been conducted to compare the efficacy of anterior cervical power plates with other plates through animal testing, which showed little difference between power plates and normal plates for anterior cervical fusion; some scholars compared the clinical outcomes of 15 cases of anterior cervical fusion and 18 cases of posterior laminoplasty with a mean follow-up of The average follow-up after surgery was 15 and 10 years.
The results showed no difference in postoperative neurological improvement between the two surgical approaches, with three cases of reoperation in anterior cervical fusion and one case of C5 nerve block paralysis in posterior laminoplasty and five cases of intractable cervical axial syndromes (AS), i.e., pain and muscle spasm in the neck and shoulder and back, but no cases requiring secondary surgery, the authors noted. Anterior cervical fusion is feasible for single-segment disc herniation, and posterior laminoplasty is required for multi-segment herniation or combined cervical spinal stenosis.
Lee et al. compared the results of anterior treatment with the thinner Atlantis plate and the wider Zephir plate and showed that the Atlantis group had a lower incidence of dysphagia than the Zephir group, suggesting that The thickness of the plate was positively correlated with the incidence of postoperative dysphagia.
The use of Zephir plate internal fixation system combined with titanium mesh implant fusion can achieve immediate stabilization, and only a short period of postoperative neck brace protection is required without external fixation, which can reduce patient pain. However, it has also been reported in the literature that the complication rate after titanium mesh implant is about 10%, which is related to the detachment and sinking of the titanium mesh.
1.1.2 Anterior cervical spine canal enlargement Continuous compression of the anterior tissues of the spinal cord due to cervical spondylosis is common clinically. Compression of the cervical medulla in one to two segments can be relieved by direct removal of the compressor through the anterior approach. In patients with multisegmental cervical stenosis with anterior cervical medullary compression, it is not possible to directly relieve the anterior spinal cord compression with this surgical approach. Therefore, the following surgical approach has been proposed, in which multiple vertebral bodies are split longitudinally in the anterior median of the vertebral body, and the split vertebral body is propped up on both sides to achieve spinal canal augmentation. The cavity formed after the split can be used to decompress the cervical medulla anteriorly, and the cavity formed can be used for bone grafting, and the bone graft can be fused stably by the elastic retraction force of the vertebral body.
This surgery is a newer surgical method, in which the anterior vertebral splitting, bone grafting and internal fixation can theoretically both fix the destabilized segment and enlarge the canal of the compressed segment, but whether it will damage the anterior column of the cervical spine, whether the splitting and enlargement will compress the vertebral arteries on both sides, and whether it will lead to the instability of the cervical spine, etc. still need further clinical observation and demonstration. At present, there are only a few reported cases of this procedure, and the specific efficacy of the procedure has yet to be further clinically verified.
1.1.3 The minimally invasive surgical system (MISS) was first reported by Smith et al. in 1964, when papain was used for chemical lysis of the nucleus pulposus to treat lumbar disc herniation, revealing the prologue of minimally invasive spine surgery. The main minimally invasive cervical spine surgery sub-operative procedures are percutaneous cervical nucleus pulposus (PCN), intradiscal electrothermal treatment (IDET), radiofrequency ablation myeloplasty of cervical discs ( radiofrequency nucleoplasty (RN), and micro endoscopic discectomy (MED).
In recent years, some micro instruments for discectomy, bone scraping and nerve root enlargement have been improved, and a large number of cases have been done with satisfactory results while strictly selecting the indications. boehm performed percutaneous cervical disc removal in 13 patients with cervical spondylosis, including 4 nerve root types and 9 spinal cord types, with an average follow-up of 17 months, of which 4 cases had complete remission of nerve block symptoms, 8 cases had partial remission, and 1 case There were no intraoperative or postoperative complications, and it is believed that this method can be extended for the treatment of spinal stenosis and other diseases. Minimally invasive surgery for cervical spondylosis and cervical disc herniation under cervical discoscopy is a surgical method that is easy to master and has excellent efficacy if the indications are strictly selected.
1.2 Anterior non-fusion surgery mainly includes artificial disc replacement. Fusion is currently the conventional procedure for the treatment of cervical spondylosis, but the acceleration of degeneration of the upper and lower segments after cervical fusion has received increasing attention. Fusion also causes biomechanical changes in the spine, and there are complications with bone grafting and internal fixation devices and chronic pain in the bone donor area. In addition, the primary goal of anterior cervical surgery is to relieve spinal cord compression rather than fusion, and these are challenges that plague spine surgeons.
Artificial cervical disc replacement (ACDR), which provides spinal cord decompression and stability while restoring and maintaining the height of the intervertebral space, segmental stability, and normal cervical motion, is a major advance in the treatment of cervical disc disease and demonstrates a new approach to the surgical treatment of cervical spondylosis. Jensen et al. reported that Bryan’s artificial disc, which had been grown in humans and orangutans for 8 to 10 months, was removed to study the growth of new bone within it, and the general observation was that the new bone had grown inward through the porous coating, and the histological staining showed a blue osteogenic area of 10% to 15%, with an endogenous bone growth rate of approximately 30.1%. Dmitriev et al. reported that in 10 cervical spine specimens, they compared the pressure load and range of motion of the fused segment during rotation, flexion, extension and lateral bending of the vertebral body with those of the upper and lower segments during postoperative rotation, flexion, extension and lateral bending of the vertebral body.
Pickett et al. reported a comparative clinical study of anterior cervical fusion and Bryan’s artificial disc replacement in 46 patients with neurogenic and spinal cervical spondylolisthesis. The results showed that the results of artificial disc replacement were better than those of anterior cervical fusion.
Pickett et al. conducted a 24-month follow-up study on the postoperative cervical kinematic status of 20 patients who underwent single- or dual-segment cervical artificial disc replacement, and the results showed that the cervical motion remained good after surgery, with no statistically significant changes in vertebral rotation, disc height, or vertebral displacement before and after surgery. However, a series of negative reports were also found, with Bryan et al. reporting eight cases of various complications requiring re-hospitalization in 146 Bryan replacement patients.
Leung et al. reported a clinical study on the incidence of heterotopic ossification after cervical artificial disc replacement, in which they selected 90 patients for Bryan artificial disc replacement and found that 16 (17.8%) of them developed The authors concluded that age and gender were risk factors for this condition, with a higher incidence in older male patients. Even though artificial discs are very effective, no research has been done on the efficacy of artificial discs for cervical instability, and since this work has not been performed for a long time, the long-term efficacy needs to be further observed.
2.Posterior approach surgery
In the 1960s, Dong Fangchun and others basically used posterior laminectomy for cervical spinal stenosis due to various causes, and the representative one is the “uncovered laminectomy” introduced by Dong Fangchun and other scholars. After complete laminectomy, the spine is fully decompressed and the operation is effective in the short term, but this is not the case clinically. There are many disadvantages of laminectomy, such as small cushion gap and high pressure in the spinal canal in cases of spinal stenosis, and when using a variety of biting forceps to remove the lamina, the biting forceps repeatedly hit the spinal cord and cause direct injury to the spinal cord; postoperative spinal instability, late goose neck deformity and extensive scarring and contraction, and the anterior and posterior diameter of the spinal canal gradually shrinks, and symptoms recur or worsen.
In 1977, Hirabayashi of Japan designed the posterior cervical spine canal enlargement and shaping, that is, the posterior cervical spine single-opening surgery, but most of the cervical spondylosis of all subtypes have a common lesion basis, that is, degeneration and instability, and the stability of the spine should also be considered when performing posterior decompression of the vertebral plate or canal shaping.
In 1989, Roy-Camile first reported the use of posterior cervical lateral plate screw internal fixation for cervical fracture dislocation instability. However, traditional posterior internal fixation of the cervical spine, such as spinal plates and wires, have problems such as unstable fixation or limited application. Although anterior plates can solve most cervical instability problems, they cannot provide effective stability for damage to posterior cervical structures.
In contrast, lateral block plate fixation for cervical instability aims to rebuild or restore the stability of the cervical spine with screws fixed to the articular eminence to achieve strong fixation with short segmental fixation characteristics, which can restore the stability of the cervical spine while maximizing the preservation of cervical motion.
Posterior single-opening with internal fixation, this procedure is a better treatment for cervical instability and not only allows for spinal decompression but also provides strength and stability to the posterior cervical spine.
Lindsey et al. performed a biomechanical study showing that internal fixation with a lateral block screw plate increased segmental stability of the cervical spine by 92% in flexion and 60% in extension, and that posterior cervical lateral block internal fixation improved implant fusion rates, had better biomechanical stability and multiplanar stabilization, whereas internal fixation with a spine plate increased stability by only 33% in flexion and was completely ineffective in The stability of spinal plate internal fixation was only increased by 33% in flexion and was completely ineffective in extension.
Matsumura et al. used both laminoplasty and posterior lateral plate fixation to treat unstable cervical spinal stenosis and showed that the spinal cord was decompressed by laminoplasty, the cervical spine was stabilized by internal fixation of the lateral plate, and long-term stabilization was achieved by articular eminence and interlaminar bone grafting, with both decompression and restabilization accomplished through the same incision.
Houtent et al. concluded that posterior decompression with lateral plate fixation avoids the complications of anterior decompression and reduces the likelihood of development of posterior synostosis due to simple posterior laminotomy decompression or shaping, and the efficacy can reach or even exceed that of anterior surgery, with varying degrees of improvement in neurological function according to JOA. Wang et al. concluded that cervical lateral block internal fixation provides strong three-dimensional internal fixation, reconstructs the posterior cervical tension band, and provides high and effective stability for all types of cervical spine injuries.
The Department of Orthopaedic Surgery of our hospital currently performs anterior cervical discectomy and fusion, cervical discectomy with percutaneous aspiration, cervical disk cryo-plasma ablation myeloplasty, uncovered laminectomy, artificial disk replacement, posterior single-opening plus internal fixation, posterior laminoplasty, and posterior arch fixation and decompression fusion.