Posterior cervical vertebroplasty has become a better treatment for cervical spinal stenosis, multisegmental spinal cord type cervical spondylosis, and continuous and mixed cervical posterior longitudinal ligament ossification. However, because there are two options available for posterior cervical spine opening, single-opening and double-opening, there are few comparative studies of clinical analysis of the two postoperative procedures in China. There is a certain amount of confusion among clinicians. For this reason, we made a retrospective clinical analysis and comparison of 2 different types of cervical single- and double-opening kyphoplasty to evaluate their effects and provide reference for clinicians.
1.Data and methods
(1) General information
Fifty patients with multisegmental spinal cord spondylosis were retrospectively analyzed, and 28 cases of posterior cervical single-opening vertebroplasty were performed as group A. There were 18 males and 10 females; ages ranged from 45 to 72 years, with an average of 58 years. The duration of the disease ranged from 6 to 50 months, with a mean of 20.5 months. There were 22 cases involving 3 segmental lesions and 6 cases involving 4 segmental lesions. 22 cases of posterior cervical double-opening vertebroplasty were performed as group B. There were 14 males and 8 females, aged 47 to 69 years, with an average age of 56 years. The duration of the disease ranged from 5 to 45 months, with a mean of 20.1 months. Fifteen cases involved 3-segment lesions and 7 cases involved 4-segment lesions. In both groups, cervical spine x-ray, CT and MRI were performed before surgery, and the spinal canal degeneration was obvious, and the sagittal diameter was narrowed to different degrees; the spinal cord MRI sagittal position showed that the anterior part of the spinal cord was compressed by the protruding disc or bone.
(2) Surgical procedures
All procedures were performed under general anesthesia with tracheal intubation. The patient was placed prone on a 4-point spinal frame with the head in a Mayfield cranial brace, and the posterior superior iliac crest was sterilized and toweled for bone extraction. A median longitudinal incision is made at the back of the neck. The skin and subcutaneous tissues are incised sequentially, and the muscles on both sides of the spine are separated.
Single-opening vertebroplasty group: The spinous processes and both sides of the vertebral body at the surgical site are exposed, the spinous processes are cut from the roots, and holes are made in the roots of all remaining spinous processes, with the left side of the vertebral plate selected as the opening side and the right side as the portal side. On the portal side, the outer layer of the vertebral plate is removed from the medial edge of the spinous process with a grinding drill, and the groove is “U”-shaped, with a width of about 1.0-1.5 cm, and the whole layer of the vertebral plate is ground off on the open side, and the intervertebral ligament is removed at the groove. on.
Double-opening vertebroplasty group: The spinous process and both sides of the vertebral plate are also exposed, and the end of the spinous process is cut away and left as an implant. A pneumatic microdrill was used to make longitudinal grooves on both sides of the medial edge of the tuberosity in a “u” shape. A wire saw is passed under the spinous process of C3-7 and between the dural sac, and the spinous process is cut longitudinally from the median. The vertebral plate is lifted off to the sides and the sublaminar adhesions are removed. The cut spinous process is trimmed (if not enough iliac bone can be taken), the central part of the bone block and the split spinous process are perforated, a 10-gauge suture is threaded, the trimmed spinous process or iliac bone strip is implanted, and the ligature is fixed.
The operation should be performed gently to avoid disturbing the spinal cord as much as possible, and methylprednisolone 1000 mg intravenous drops can be used intraoperatively to protect the disturbed spinal cord. The bone graft should be fixed firmly and the portal axis on both sides should be intact, otherwise the efficacy and postoperative follow-up will be affected. Postoperatively, drains were routinely placed and removed after 48 h. After 1 to 2 d of postoperative bed rest, the cervical collar was protected and moved out of bed, and the cervical collar was fixed for 4 to 6 weeks.
(3) Evaluation of efficacy
Neurological function was evaluated using JOA score to evaluate the neurological function of patients before and 2 years after surgery and to calculate the improvement rate of JOA score. The improvement rate = (postoperative JOA score a preoperative JOA score), (17 a preoperative JOA score) x 100%.
The preoperative and postoperative axial symptoms were graded according to the severity of the patients’ symptoms and their impact on daily life, and the axial symptoms were classified as excellent, good, acceptable, or poor. Those who were rated as excellent or good were classified as those without axial symptoms, while those who were acceptable and poor were classified as those with axial symptoms.
For imaging evaluation x-ray measurements, the following measurements were performed on cervical hyperextension and hyperflexion position x-rays before surgery and at the 2-year postoperative follow-up of patients. Total cervical spine mobility (range of the motion, ROM measurement.
(4) Statistical analysis
The experimental data were expressed as mean ± standard deviation. The results obtained were analyzed by the SPSS 16.0 statistical software, and the improvement rate of JOA score and the angle of loss of cervical mobility between the two groups before and after the operation were tested by the t-test of the two interrogation groups. The incidence of postoperative axial symptoms was tested by the X2 test of frequency distribution between the two groups. p>O.05 was considered a statistically significant difference.
2.Results
(1) Recovery of neurological function
The improvement rate of JOA score 2 years after surgery was (52.0±21.4%) for patients in group A and (52.7±19.8%) for patients in group B. The difference between the two groups was not statistically significant (P=O.970>0.05).
(2) Axial symptoms
At 2 years after surgery, 12 cases in group A had axial symptoms, 8 cases could, 4 cases were poor, the incidence rate was 42.9%. 8 cases in group B had axial symptoms, 6 cases could, 2 cases were poor, the incidence rate was 36.4%. Using X: test, the difference between the two groups was not statistically significant (X2=0.216, P=0.642>0.05).
(3) Cervical spine mobility
ROM loss (3.9±1.8)o in group A and (3.6±1.5) in group B at 2 years postoperatively. (Posterior extension angle loss was predominant in both groups. The mean was 6.40), and there was no statistically significant difference between the two groups using independent sample t-test (P=O.492>0.05). However, the postoperative maintenance of cervical mobility in group B was better than that in group A.
3. Discussion
The basic principle is to decompress the spinal canal or shape the vertebral plate, and at the same time use the physiological protrusion of the cervical spine to shift the spinal cord to the dorsal side to achieve the purpose of relieving the spinal cord compression. The advantage of this procedure over the traditional laminectomy is that most of the surgery is performed outside the spinal canal, reducing the possibility of injury to the spinal cord. At the same time, the bone groove is at the inner edge of the small joint, allowing the stability of the intervertebral joint to be preserved. The posterior structure of the vertebral canal is preserved to the maximum extent with the bone graft homeostasis after open-door shaping of the spinal canal. Postoperative instability of the cervical spine was avoided. However, the relevant literature also reports complications associated with posterior cervical canaloplasty, especially axial symptom (AS) of neck and shoulder pain, the incidence of which is reported to be as high as 45% to 80% ts. In China, Sun Yu et al. concluded by comparing the preoperative and postoperative cervical spine mobility that posterior cervical canal enlargement and shaping can reduce both the total cervical spine mobility and the relative mobility of each vertebral interrogation, and concluded that The posterior cervical kyphoplasty requires a median incision at the back of the neck and extensive stripping of the paravertebral muscles on both sides, which can lead to extensive adhesions and scar tissue between the muscles at different levels after surgery, resulting in reduced cervical mobility, neck and shoulder stiffness, poor blood flow and ischemia, and possibly myofasciitis, leading to the development of neck and shoulder pain, or axial symptoms. follow-up, found that postoperative patients with heavy axial symptoms had significantly lower neck ROM than patients with mild axial symptoms; therefore, it is believed that postoperative axial symptoms are also associated with reduced total postoperative cervical mobility. Since the patient’s neck ROM is so important. Does the clinical choice of opening the door then have an effect on it?
In this experiment, we compared JOA scores, axial symptoms, and cervical mobility before and after surgery in patients undergoing posterior cervical single- and double-opening vertebroplasty by grouping them. The results showed that both groups were able to achieve good neurological improvement, but the incidence of axial symptoms occurred to varying degrees after surgery, although the difference between them was not statistically significant. However, double-opening vertebroplasty had a lower incidence of axial symptoms and loss of cervical motion than single-opening vertebroplasty. This is related to the fact that bifacial canalplasty is performed by symmetrically abducting both sides of the vertebral plate to obtain decompression space on both sides. Compared with unifacial canalplasty, bifacial canalplasty obtains a structure that more closely resembles the normal spinal column, allowing the postoperative symmetric growth of the paravertebral muscles at different levels peeled off during surgery and effectively preventing excessive growth of scar and tissue adhesions.
What kind of posterior cervical kyphoplasty is used by clinical operators to treat patients with multisegmental spinal cord spondylosis? Shigeru, a Japanese scholar, compared 33 patients who underwent single-opening vertebroplasty with 20 patients who underwent double-opening vertebroplasty, and concluded that there was no significant difference in canal volume between the two groups, while also suggesting the relative indications for each procedure. They concluded that unilateral canalplasty is indicated for (1) spinal cervical spondylosis with unilateral radiculopathy, (2) severe ossification of the posterior longitudinal ligament, and (3) patients with a small spinous process that precludes bifacial canalplasty.
Double-opening vertebroplasty is indicated for: (1) patients with usual spinal cord cervical spondylosis; (2) patients with small, mild posterior longitudinal ligament ossification; (3) spinal cord cervical spondylosis with bilateral radiculopathy; (4) patients with cervical stenosis combined with instability who must undergo posterior cervical spine surgery. Some domestic scholars also adopt the anterior cervical segmental decompression and bone grafting plate for the same treatment.
Although the multi-segmental spinal cord type cervical spondylosis has achieved better immediate stability, there is a risk of plate fracture and screw loosening, and patients have to bear higher medical costs, which may not be a better choice for patients.
In summary, for the treatment of multi-segmental spinal cord plow cervical spondylosis, clinical operators can use different open-door methods according to different indications. Since cervical spine surgery is a high-risk procedure, it is also important to choose different procedures according to the operator’s own proficiency.