The effects of C2 instability on cervical curvature changes and clinical outcomes after sub-axial cervical expansive door-open laminoplasty

The effects of C2 instability on cervical curvature changes and clinical outcomes after sub-axial cervical expansive door-open laminoplasty | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The effects of C2 instability on cervical curvature changes and clinical outcomes after sub-axial cervical expansive door-open laminoplasty Liang Ma, Xiangyu Meng, Haiyan Xi, Abuduwupuer HAibier, Changgui Shi, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4009212/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective: To investigate the impact of C2 vertebral instability on the sagittal parameters of the cervical spine and the clinical efficacy after cervical laminoplasty with unilateral open-door cervical expansive laminoplasty (EMOL). Methods: In a retrospective analysis of 18 patients with cervical 2 vertebral instability from August 2017 to August 2021 in the second Affiliated Hospital of Naval Military Medical University and the first Affiliated Hospital of Xinjiang Medical University treated with single open-door vertebroplasty (C3-6 or C3-7), 36 patients with stable cervical 2 cervical EMOL during the same period (control group). To evaluate the changes in sagittal parameters before and after surgery in the two groups, including C0-2 Cobb angle, C2-7 sagittal axis distance (sagittal vertical axis, SVA), C2-7 Cobb angle, T1 tilt angle (T1-Sl); The postoperative outcome was evaluated using the visual analogue score for neck and shoulder pain (visual analog scale, VAS) and the Japan Society Cervical Function Score (Japanese 0rthopaedic Association, JOA). Results: Compared to preoperative values, both the observation group and the control group showed significant improvement in postoperative VAS scores and JOA scores. The JOA scores were 14.0±1.6 and 13.1±1.6, with improvement rates of 68.42% and 58.06%, respectively, compared to their respective preoperative scores. However, there was no significant difference between the two groups. The observation group had significantly greater cervical range of motion (ROM) before surgery compared to the control group (p<0.05). At the last follow-up, the observation group showed a significant decrease in C2-7 Cobb angle from preoperative (8.2±0.1)° to (5.1±2.5)° (p<0.05). Cervical ROM decreased from preoperative (39.8±3.6)° to (31.6±4.5)° (p<0.05). C0-2 Cobb angle increased from preoperative (22.0±3.7)° to (25.8±3.1)° (p<0.05). C2-7 SVA increased from preoperative (-19.6±3.4)° to (-15.8±3.7)° (p0.05). The observation group showed a decrease in C2 vertebral displacement from preoperative (4.5±0.9) mm to (3.3±0.5) mm (p0.05). In both groups, postoperative follow-up showed a significant increase in C0-2 Cobb angle and C2-7 SVA, a non-significant difference in T1 slope, and a significant decrease in C2-7 Cobb angle and cervical ROM compared to preoperative values. However, there were no significant differences between the two groups in the above-mentioned parameters (p>0.05). Conclusion: C2 vertebral instability does not affect the sagittal parameters and efficacy of cervical laminoplasty with EMOL. EMOL surgery for cervical myelopathy with C2 vertebral instability is effective and reliable, without exacerbating C2 vertebral instability. Furthermore, it maintains good sagittal balance of the cervical spine. lower cervical vertebra Cervical spondylotic myelopathy Single door enlarged spinal canal plasty Sagittal plane balance Cervical instability Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Multisegmental cervical spondylotic myelopathy (MCSM), cervical spinal stenosis, and ossification of the posterior longitudinal ligament (OPLL) are pathological changes that cause compression of the cervical spinal cord [1] . Patients often present with sensory and motor deficits in the limbs, as well as urinary and fecal dysfunction [2] . With changes in lifestyle, the incidence of these conditions has increased, significantly impacting patients' quality of life and being a major cause of disability.Posterior cervical expansive door-open laminoplasty (EODL) is a primary surgical approach for treating multisegmental cervical spinal cord compression [3-4] . EODL has been proven to have clear and long-lasting efficacy in improving patients' neurological function and relieving cervical spinal cord compression [5] . EODL is a non-fusion surgical technique that preserves cervical spine mobility to a certain extent. Moreover, EODL does not increase cervical instability in patients with pre-existing instability [6] . Additionally, EODL preserves the posterior column structures, effectively reducing surgical trauma and postoperative complications [7] . However, due to the extensive dissection of muscles, ligaments, and other structures during the procedure, there is a possibility of changes in sagittal parameters of the cervical spine, which may affect clinical outcomes or lead to postoperative axial pain [8-9] . The C2 vertebra plays a crucial role in measuring sagittal parameters of the cervical spine, as multiple parameters are measured with reference to the C2 vertebra. However, there is limited research on whether C2 vertebral instability affects the sagittal parameters and clinical outcomes of lower cervical spine EODL [10] . This study aims to retrospectively analyze the clinical and radiographic data of patients who underwent lower cervical spine EODL in our orthopedic department to evaluate the impact of C2 vertebral instability on sagittal parameters and clinical outcomes after EODL. 1 Objects and methods Subjects and methods 1.1General Information In this study, the clinical data and follow-up records of patients undergoing cervical EODL in the first Affiliated Hospital of Naval Military Medical University from August 2017 to August 2021 were selected. The patients were divided into the cervical 2 vertebral instability group (observation group) and the cervical 2 vertebral stabilization group (control group), and the patients treated by EODL surgical treatment in the same time according to the age, gender and surgical segment matching (1:2). All patients signed the informed consent before surgery, and the study was approved by the hospital ethics committee. 1.2Inclusion criteria: (i) Presence of symptoms and signs of cervical spinal cord compression before surgery. (ii) Imaging showing evidence of Multisegmental Cervical Spondylotic Myelopathy (MCSM) or Ossification of Posterior Longitudinal Ligament (OPLL). (iii) Underwent lower cervical spine EODL surgery. (iiii) Follow-up for at least 2 years with complete imaging data. 1.3Exclusion criteria ： (i) Presence of cervical radiculopathy and concurrent radicular cervical spine disease. (ii) Concurrent posterior cervical pedicle screw-rod fixation or anterior cervical plate and screw fixation. (iii) History of previous cervical spine surgery or trauma. (iiii) Severe cervical kyphosis deformity or presence of cervical spine infection, tumor, etc. (iiiii) Concurrent rheumatoid arthritis or ankylosing spondylitis, and other related diseases. According to the inclusion and exclusion criteria, a total of 18 patients were selected for the observation group, including 12 males and 6 females. The age ranged from 45 to 72 years, with an average age of (58.2±3.1) years. The body mass index (BMI) ranged from 18 to 27 kg/m2, with an average BMI of (23.8±2.3) kg/m2. The duration of the disease ranged from 5 to 14 months, with an average duration of (9.7±5.5) months. Two patients had concomitant hypertension, and one patient had diabetes. Among the patients, 8 underwent surgery at the C3-6 level, and 10 underwent surgery at the C3-7 level.The control group consisted of 36 matched patients, including 25 males and 11 females. The age ranged from 45 to 72 years, with an average age of (58.5±2.9) years. The body mass index (BMI) ranged from 17 to 28 kg/m2, with an average BMI of (23.5±2.1) kg/m2. The duration of the disease ranged from 6 to 13 months, with an average duration of (9.5±5.6) months. Three patients had concomitant hypertension, and two patients had diabetes. Among the patients, 26 underwent surgery at the C3-6 level, and 10 underwent surgery at the C3-7 level. 1.4 Surgical method The patient is placed under general anesthesia and positioned prone on a plaster bed. The surgical field is prepared with routine disinfection and draping. A midline incision is made posterior to the neck, extending from the spinous processes of C2 to C7, with a length of 8-10cm. The skin, subcutaneous tissue, fascia, and nuchal ligament are dissected using an electric scalpel. The paraspinal muscles are then dissected bilaterally along the periosteum, exposing the area from the lower half of the C2 spinous process to the spinous processes and laminae of C3-6 or C3-7. Using a burr, slots are created at the junction of the lamina and lateral mass on the side with more compression, which serves as the "open-door" side. The laminae are thinned and removed bilaterally, deep to the spinal canal. On the side with less compression, known as the "hinge" side, the laminae are thinned and the ventral cortex is preserved. The laminae of C3-6 or C3-7 are sequentially lifted from caudal to cranial, and mini titanium plates (arch plates) are used to fixate the lateral mass and laminae on the open-door side. Any remaining bone in the inner edge of the lateral mass and intervertebral foramen area is carefully removed using rongeurs and curettes. Adhesions between the dura mater or nerve roots and the ligamentum flavum are released. Hemostasis is ensured throughout the procedure. After confirming satisfactory pulsation of the dura mater, the surgical site is irrigated with saline solution, and drainage is placed before closing the incision layer by layer. Postoperatively, the patient is instructed to wear a cervical collar for 2-3 weeks as per routine. 1.5 Observed indicators (1) Measurement of sagittal parameters: Preoperative and postoperative cervical spine lateral, flexion-extension, CT, and MRI images are obtained. The PACS 3.0 system software is used to measure the following sagittal parameters on cervical X-ray images: C0-2 Cobb angle, C2-7 sagittal vertical axis (SVA) in millimeters, C2-7 Cobb angle, T1-Slope, range of motion (ROM) of the cervical spine, displacement of the C2 vertebral body (measured as the distance between the posterior edge of the C2 vertebral body and the posterior edge of the C3 vertebral body on flexion-extension X-ray images in millimeters), and the angle of motion at the C2/3 level (measured as the difference in angle at the C2/3 level on flexion-extension X-ray images). Two physicians independently measure the imaging parameters twice using the described method. The average value of the measurements is taken as the final measurement data. The assessors are blinded to the study content. Please refer to Figure 1 for specific measurement methods. (2) Clinical efficacy assessment: Preoperative and postoperative pain and neurological function improvement in patients are evaluated using the visual analog scale (VAS) for neck and shoulder pain and the Japanese Orthopaedic Association (JOA) score for cervical spine function. The improvement rate (%) is calculated as follows: Improvement rate (%) = (Postoperative JOA score - Preoperative JOA score) / (17 - Preoperative JOA score) × 100%. (3) Complications: Intraoperative and postoperative complications are recorded, including dural tear, nerve injury, postoperative C5 nerve root palsy, postoperative infection and hematoma, postoperative axial pain, failure of internal fixation, and re-closure. 1.6 Statistical methods The data were analyzed using SPSS 26.0 software. Continuous variables are presented as mean ± standard deviation. Paired sample t-tests were used for within-group comparisons of preoperative and postoperative data, while independent sample t-tests were used for between-group comparisons. Categorical data were analyzed using chi-square tests or Fisher's exact tests. The correlation between clinical efficacy and changes in imaging parameters was analyzed using Pearson correlation tests. A p-value < 0.05 was considered statistically significant. 2 Results 2.1 Experimental flow chart The flow chart of the two groupings is shown in Figure 2 . Figure 2 Flow chart of test grouping 2.2 Comparison of preoperative data between the two groups ：Baseline data on age, sex, body mass index, disease duration, surgical segment, follow-up time, operation time, bleeding volume, and complications were comparable (p> 0.05). See Table 1 . Table 1 Basic preoperative data of the two groups Items Observation group （ n=18 ） Control group （ n=36 ） χ 2 /Fisher's exact test P Age 58.2±3.1 58.5±2.9 0.587 0.561 Sex (n) 12/6 25/11 0.468 0.494 Disease course (month) 9.7±5.5 9.5±5.6 1.563 0.134 Follow-up time (years) 2.4±0.4 2.9±1.3 1.509 0.141 BMI（kg/m 2 ） 23.8±2.3 23.5±2.1 1.489 0.152 Diagnosis (n) 0.139 0.933 OPLL disease 6/33.3 10/27.8 Cervical spinal stenosis 10/56.6 22/61.1 Cervical herniated disc 2/11.1 4/11.1 Surgical segment (n) 0.643 0.423 C3-6 8/44.4 26/72.2 C3-7 10/55.6 10/27.8 Operation time (min) 112.2±3.8 114.2±3.7 1.595 0.120 bleeding volume（ml） 95.0±6.8 97.5±4.6 1.293 0.205 Complication(n) Axial symptoms 3/16.7 2/5.6 0.232 0.630 Wound infection 0/0.0 1/2.8 0.509 0.475 C5Nerve root paralysis 1/5.6 3/8.3 0.135 0.713 2.3 Neurological function assessment and vas scores During the postoperative follow-up, it was observed that the JOA score in the observation group improved from 7.5±1.2 preoperatively to 14.0±1.6 postoperatively, with an improvement rate of 68.42%. In the control group, the JOA score improved from 7.7±1.0 preoperatively to 13.1±1.6 postoperatively, with an improvement rate of 58.06%. There were no significant differences in JOA scores between the two groups at the last follow-up. It was also noted that the VAS scores for neck pain significantly decreased in both groups during the postoperative follow-up.See Table 2 . Table 2: neurological function assessment and vas scores Items Observation group（n=18） Control group（n=36） t P Neck VAS score Preoperative 7.3±0.5 7.3±0.9 0.024 0.981 The last follow-up 1.1±0.1 1.0±0.2 0.711 0.482 JOA score Preoperative 7.5±1.2 7.7±1.0 0.562 0.578 The last follow-up 14.0±1.6 13.1±1.6 1.870 0.067 2.4 Evaluation of radiographic parameters Before the surgery, the cervical ROM was (39.8±3.6)° in the observation group and (36.3±4.3)° in the control group, with a statistically significant difference (P<0.05). At the last follow-up in the observation group, compared to preoperative values, the C0-2 Cobb angle increased from (22.0±3.7)° to (25.8±3.1)°; C2-7 SVA increased from (-19.6±3.4) mm to (-15.8±3.7) mm; C2-7 Cobb angle decreased from (8.2±0.1)° to (5.1±2.5)°; and cervical ROM decreased from (39.8±3.6)° to (31.6±4.5)°. All these parameters showed statistically significant differences within the observation group (P0.05). In the control group, at the last follow-up compared to preoperative values, the C0-2 Cobb angle increased from (22.8±2.7)° to (25.3±2.9)°; C2-7 SVA increased from (-18.7±3.5) mm to (-15.3±1.4) mm; C2-7 Cobb angle decreased from (8.2±0.2)° to (4.9±0.8)°; and cervical ROM decreased from (36.3±4.3)° to (30.6±4.5)°. All these parameters showed statistically significant differences within the control group (P0.05). There were no significant differences between the two groups in the above-mentioned parameters at the last follow-up compared to preoperative values (P>0.05) .See Table 3 . In the observation group, at the last follow-up compared to preoperative values, the displacement of the C2 vertebral body decreased from (4.5±0.9) mm to (3.3±0.5) mm, which was statistically significant (P0.05) .See Table 4 . Table 3 : Sagittal Parameters of the Cervical Spine in the Two Groups of Patients Items Observation group（n=18） Control group（n=36） t P C 0-2 Cobb（°） Preoperative 22.0±3.7 22.8±2.7 0.716 0.479 The last follow-up 25.8±3.1 25.3±2.9 1.523 0.137 C 2-7 SVA（mm） Preoperative -19.6±3.4 -18.7±3.5 0.898 0.376 The last follow-up -15.8±3.7 -15.3±1.4 0.655 0.517 C 2-7 Cobb（°） Preoperative 8.2±0.1 8.2±0.2 0.451 0.655 The last follow-up 5.1±2.5 4.9±0.8 0.440 0.687 T1-Slope（°） Preoperative 27.0±5.0 26.1±3.4 0.616 0.542 The last follow-up 26.4±2.8 26.0±2.5 0.464 0.646 Neck ROM（°） Preoperative 39.8±3.6 36.3±4.3 4.454 0.013 The last follow-up 31.6±4.5 30.6±4.5 0.666 0.510 Figure3 Comparison of patient Neck ROM in the two treatment groups Table 4 Assessment of the degree of neck 2 instability in the observation group before surgery and at the last follow-up visit Items Preoperative Postoperative follow-up t P Neck 2 vertebral displacement value（mm） 4.5±0.9 3.3±0.5 4.163 0.020 Neck 2 / 3 gap activity angle（°） 9.9±1.7 8.6±2.5 0.926 0.351 2.5 Complications In the observation group, 3 cases (16.67%) experienced postoperative axial pain, while in the control group, there were 2 cases (5.56%). One case in the observation group developed C5 nerve root palsy, while in the control group, 3 cases developed C5 nerve root palsy. All patients in both groups achieved recovery through conservative treatment. One case in the control group experienced postoperative wound infection (2.8%), while no infection cases were observed in the observation group. Neither group experienced cerebrospinal fluid leakage, nerve injury, failure of internal fixation, re-closure, or hinge fracture .See Table 5. 2.4 Relationship between Changes in Sagittal Parameters and Clinical Efficacy in the Observation Group The relationship between changes in sagittal parameters and clinical efficacy in the observation group is shown in Table 5. The improvement rate of neurological function was 68.42%. However, there was no significant correlation between changes in sagittal parameters and cervical range of motion (ROM) with clinical efficacy (P>0.05). Table 5: Relationship between Changes in Sagittal Parameters and Clinical Efficacy in the Observation Group Items Neck 2 vertebral displacement value（mm） C2-7 Cobb（°） Neck ROM（°） Neck VAS score r 0.199 0.021 0.003 P 0.428 0.901 0.986 Rate of neurological improvement（%） r 0.327 0.128 0.022 P 0.185 0.612 0.929 Note:cervical ROM is cervical mobility;neurological improvement rate:(postoperative JOA score-preoperative JOA score)/(17-preoperative JOA score) 100%. 2. 6 Typical cases Case 1, female patient, 50 years old. A, B are preoperative sagittal MRI images, showing varying degrees of disc protrusion at the C4/5, C5/6, and C6/7 levels. C, D are preoperative anterior-posterior X-rays, showing loss of cervical lordosis. E, F are preoperative flexion-extension X-rays, showing instability of the C2 vertebra. G, H are postoperative follow-up lateral X-rays, showing good position of the internal fixation. I, J are postoperative follow-up flexion-extension X-rays, showing no significant changes in the instability of the C2 vertebra.See Figure 4 . Figure 4 Typical case 1. Case 2, male patient, 57 years old. A, B are preoperative sagittal MRI images, showing varying degrees of stenosis at the C3/4, C4/5, and C5/6 levels, with ossification of the posterior longitudinal ligament at C3/4. C, D are preoperative anterior-posterior X-rays, showing slight straightening of the cervical curvature. E, F are preoperative flexion-extension X-rays, showing instability of the C2 vertebra. G, H are postoperative follow-up lateral X-rays, showing good position of the internal fixation. I, J are postoperative follow-up flexion-extension X-rays, showing no significant changes in the instability of the C2 vertebra.See Figure 5 . Figure 5 Typical case 1. 3 Discussion In the 1970s, Hirabayashi et al. first reported the posterior cervical laminoplasty, which is now widely used for the treatment of MCSM, cervical spinal stenosis, and OPLL [11-12] . It has been proven to be a safe and effective surgical technique [13] . However, posterior cervical surgery inevitably causes damage to the muscles and ligaments in the posterior neck region, leading to changes in the normal cervical curvature, disruption of sagittal balance, and even the development of cervical kyphosis [14-15] . Postoperative cervical kyphosis has been observed in 6% to 46% of patients undergoing conventional laminoplasty procedures.In a study by Yang et al., they measured nine sagittal parameters in 164 patients who underwent cervical laminoplasty [16-17] . They found that the lower cervical curvature became straighter (decreased C2-7 Cobb angle) and the center of gravity of the head and neck shifted forward (increased C2-7 SVA). However, compensatory changes were observed in the upper cervical spine and cervicothoracic junction, such as increased cervical overextension (increased C0-2 Cobb angle, T1-Slope) to compensate for these changes [18] .Douglas et al. mentioned in their review that for patients with a significant increase in C2-7 SVA or head center of gravity SVA, alternative surgical techniques may be considered as a substitute for laminoplasty, even if there is spinal kyphosis [19] . During the C3 laminoplasty procedure, it is usually necessary to dissect the C2 lamina and the distal muscle tissue of the spinous process [20] . The posterior bony structures of C2 serve as attachment points for multiple muscles in the posterior head and neck region [21] . Excessive dissection and postoperative sagittal imbalance and axial pain may be related to this. The position of the C2 vertebra is of great significance in assessing sagittal balance of the cervical spine. However, most studies on cervical sagittal balance are based on the assumption of C2 vertebral stability [22] . In our study, we focused on the changes in cervical curvature and their clinical significance after EODL surgery, specifically considering the premise of C2 vertebral instability [23] . The results of this study showed that at the last follow-up, both the observation group and the control group showed significant improvement in JOA scores (P<0.05), which is consistent with previous reports on the efficacy of EODL surgery. Furthermore, there was no significant difference in JOA improvement between the observation group and the control group, suggesting that the increased spinal canal space and improved spinal cord function after cervical laminoplasty are not affected by C2 vertebral instability [24-26] . Our study found that the degree of C2 vertebral instability did not worsen after surgery in the observation group, and in fact, there was a reduction in C2 vertebral displacement compared to preoperative values (P<0.05). This suggests that laminoplasty not only does not increase C2 vertebral instability but also tends to stabilize the overall cervical spine. This may be attributed to factors such as muscle scarring, ossification of the C2/3 joint capsule, and fusion of inflamed joint surfaces after surgery [27-28] . However, there was a decrease in cervical range of motion compared to preoperative values (P<0.05), indicating that although EODL surgery with C2 vertebral instability leads to a decrease in lower cervical range of motion, it does not affect the stability of the C2 vertebra. Regarding cervical sagittal balance, there were no significant differences in C0-2 Cobb angle, C2-7 SVA, C2-7 Cobb angle, and T1-Slope between the two groups preoperatively. This may be because most patients in the observation group did not show obvious subluxation of the C2 vertebra in the lateral view, but instability was only evident in flexion-extension views [29-31] . Therefore, there were no significant differences in these parameters between the two groups in the preoperative lateral X-rays. However, the preoperative range of motion (ROM) of the cervical spine was greater in the observation group compared to the control group, and there was a significant difference (P<0.05). This is related to the increased mobility caused by C2 vertebral instability in the observation group.In both groups, postoperative follow-up showed a significant increase in C0-2 Cobb angle and C2-7 SVA, no significant difference in T1-Slope, and a significant decrease in C2-7 Cobb angle and cervical ROM [32] . This indicates an overall forward inclination of the cervical spine. However, there were no significant differences between the groups in the above-mentioned parameters (P>0.05). This is consistent with previous literature reporting that EODL surgery can lead to a straightening of the cervical curvature and even the development of significant kyphotic deformity due to the extensive disruption of the posterior cervical muscles. Cervical kyphosis is also a risk factor for poor postoperative outcomes in patients with cervical myelopathy [33] . The correlation analysis between the changes in these imaging parameters and the clinical efficacy evaluation of the patients shows that the decrease in cervical curvature, reduction in C2 vertebral displacement, and decrease in cervical range of motion are not significantly correlated with the improvement in neck pain and neurological function in patients [34] . It can be observed that the postoperative efficacy in patients with MCSM is mainly related to thorough decompression of the spinal cord, rather than being significantly correlated with preoperative C2 vertebral instability [35] . In conclusion, cervical laminoplasty results in a decrease in cervical range of motion (ROM) and stabilization of unstable vertebrae. Although it may not provide the same level of stability as screw fixation, it still contributes to the stability of the cervical spine. Therefore, C2 vertebral instability does not affect the sagittal parameters and clinical efficacy after laminoplasty, and it does not worsen C2 vertebral instability postoperatively. In patients with C2 vertebral instability, there is an increase in cervical range of motion, but after laminoplasty, the range of motion decreases and tends to stabilize. Cervical laminoplasty is a good treatment option for MCSM. However, it is important to note that this study had a small sample size and was retrospective in nature. Further prospective studies with larger sample sizes and longer follow-up periods are needed to further investigate this topic. Abbreviations MCSM = Multisegmental cervical spondylotic myelopathy OPLL = Ossification of the posterior longitudinal ligament EODL = Posterior cervical expansive door-open laminoplasty JOA = Japanese Orthopaedic Association VAS = Visual analogue scale BMI = Body mass index ROM = Range of motion Declarations Acknowledgements Not applicable. Authors’ contributions Study design, conception, and critical revision: Liang Ma and Weibin Sheng. Analysis and interpretation of data: Haiyan Xi and Abuduwupuer HAibier. Literature search and drafting of manuscript: Changgui Shi and Liang Ma contributed to critical revision of the manuscript for important intellectual content and approved the fnal version of the manuscript. All authors read and approved the fnal version of the manuscript. Funding Not applicable. Availability of data and materials To investigate the impact of C2 vertebral instability on the sagittal parameters of the cervical spine and the clinical efficacy after cervical laminoplasty with unilateral open-door cervical expansive laminoplasty (EMOL).Because part of the data is incomplete , so the dataset analyzed in this study is not publicly available but is available to the corresponding author on reasonable request. Ethics approval and consent to participate We confrm that all experiments were performed in accordance with the Declaration of Helsinki. The study was approved by the Ethical Committee of the Sixth Afliated Hospital of Xinjiang Medical University. Each patient provided written informed consent before participating in the study. Consent for publication Not applicable. Competing interests Not applicable. Author details 1 Department of Orthopedics of Spine, Sixth Afliated Hospital of Xinjiang Medical University, Orthopaedic Hospital of Xinjiang Uygur Autonomous Region, No.39 Wuxing Road, Urumqi, People’s Republic of China. 2 Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, People’s Republic of China. References WANG W X, ZHAO Y B, LU X D, et al. Influence of extending expansive open-door laminoplasty to C1 and C2 on cervical sagittal parameters [J]. BMC Musculoskelet Disord, 2020, 21(1): 75. Huang W, Yang SZ, Zhou BH, et al. Effect of modified posterior single door laminoplasty in treatment of multilevel cervical spondylotic myelopathy and its influence on ROM and cervical curvature [J]. The Journal of Cervicodynia and Lumbodynia, 2023, 44 (06): 982-985. LIU T, YANG H L, XU Y Z, et al. ACDF with the PCB cage-plate system versus laminoplasty for multilevel cervical spondylotic myelopathy [J]. Journal of spinal disorders & techniques, 2011, 24(4): 213-20. 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NORI S, SHIRAISHI T, AOYAMA R. Comparison between muscle-preserving selective laminectomy and laminoplasty for multilevel cervical spondylotic myelopathy [J]. Annals of translational medicine, 2020, 8(5): 160. KAMSON S, LU D, SAMPSON P D, et al. Full-Endoscopic Lumbar Fusion Outcomes in Patients with Minimal Deformities: A Retrospective Study of Data Collected Between 2011 and 2015 [J]. Pain physician, 2019, 22(1): 75-88. QIAN S, WANG Z, REN Y, et al. The cervical sagittal curvature change in patients with or without PCSM after laminoplasty [J]. Frontiers in surgery, 2022, 9: 906839. Zhao LT, Hu B. Modified open-door laminoplasty with preserved posterior cervical musculo-ligamentous complex in the treatment of cervical spondylotic myelopathy: neurological function and axial symptoms [J]. Zhongguo Zuzhi Gongcheng Yanjiu, 2021, 25 (33): 5345-5350. WANG Z, XU J X, LIU Z, et al. Spino cranial angle as a predictor of loss of cervical lordosis after laminoplasty in patients with cervical myelopathy [J]. BMC Surg, 2021, 21(1): 291. MUN H W, YUK C D, KIM T H, et al. Cervical Sagittal Imbalance after Cervical Laminoplasty in Elderly Patients [J]. BioMed research international, 2020, 2020: 8810540. Pan YB, Feng HY, Chen C, et al. Effect of Posterior Cervical Expansive Open—door Laminoplasty on Cervical Sagittal Balance [J]. Journal of Practical Orthopaedics, 2020, 26 (07): 577-582. DOI:10.13795/j.cnki.sgkz.2020.07.001. Xu Y, Li F, Xiong W, et al. The outcomes of modified laminplasty through posterior paraspinal approach compared withtraditional laminplasty using posterior midline approach in the treatment of patients with cervicalossification of the posterior longitudinal ligament[J]. Chinese Journal of Spine and Spinal Cord, 2020, 30 (03): 227-233. WANG D F, ZHU W G, WANG W, et al. The discrepancy between preoperative cervical sagittal vertical axis and T1 slope predisposes inferior clinical outcomes in patients with cervical spondylotic myelopathy after cervical laminoplasty [J]. Frontiers in surgery, 2022, 9: 1003757. HE X, ZHANG J N, LIU T J, et al. Is laminectomy and fusion the better choice than laminoplasty for multilevel cervical myelopathy with signal changes on magnetic resonance imaging? A comparison of two posterior surgeries [J]. BMC Musculoskelet Disord, 2020, 21(1): 423. ZIMERING J H, MARGETIS K. Dome Laminotomies at Adjacent Segments in Cervical Laminoplasty [J]. International journal of spine surgery, 2021, 15(5): 871-8. DU L, GAO Y, ZHAO C, et al. Laminoplasty with selective fusion at unstable segment versus laminectomy with fusion for multilevel cervical myelopathy: a case-control study [J]. BMC Musculoskelet Disord, 2021, 22(1): 426. Qi M, Chen HJ, Liu Y, et al. Laminoplasty with selective fusion in the treatment of cervical ossification of the posterior longitudinalligament with local instability[J]. Chinese Journal of Spine and Spinal Cord, 2020, 30 (03): 219-226. Pan YB. The Research Progress of Posterior Open-door Laminoplasty and Sagittal Balance of Cervical Spine[D]. World Latest Medicine Information (Electronic Version), 2020. DOI:10.27288/d.cnki.gsxyu.2020.000583. KATO M, NAMIKAWA T, MATSUMURA A, et al. Effect of Cervical Sagittal Balance on Laminoplasty in Patients With Cervical Myelopathy [J]. Global spine journal, 2017, 7(2): 154-61. KWOK S S S, CHEUNG J P Y. Surgical decision-making for ossification of the posterior longitudinal ligament versus other types of degenerative cervical myelopathy: anterior versus posterior approaches [J]. BMC Musculoskelet Disord, 2020, 21(1): 823. LI X Y, WANG Y, ZHU W G, et al. Impact of cervical and global spine sagittal alignment on cervical curvature changes after posterior cervical laminoplasty [J]. J Orthop Surg Res, 2022, 17(1): 521. QIAN S, WANG Z, JIANG G, et al. Efficacy of Laminoplasty in Patients with Cervical Kyphosis [J]. Med Sci Monit, 2018, 24: 1188-95. Yang P, Wen BT, Ge ZL, et al. Sagittal alignment changes of cervical spine in patients with cervical spondylotic myelopathy aftercervical 3-7 single-door laminoplasty and its correlation with functional status of cervical spinel[J]. Chinese Journal of Spine and Spinal Cord, 2020, 30 (02): 123-129. ONO K, MURATA S, MATSUSHITA M, et al. Cervical Lordosis Ratio as a Novel Predictor for the Loss of Cervical Lordosis After Laminoplasty [J]. Neurospine, 2021, 18(2): 311-8. hen YY, Zou XB, Ma XY, et al. Comparison of cervical motion range and curvature after C3 laminectomy and mini-titanium plate fixation after single-door vertebroplasty [J]. Zhongguo Zuzhi Gongcheng Yanjiu, 2020, 24 (12): 1805-1809. WIGUNA I, MAGETSARI R, NOOR Z, et al. Comparative Effectiveness and Functional Outcome of Open-Door versus French-Door Laminoplasty for Multilevel Cervical Myelopathy: A Meta-Analysis [J]. Open access Macedonian journal of medical sciences, 2019, 7(19): 3348-52. LAVELLE W F, RIEW K D, LEVI A D, et al. Ten-year Outcomes of Cervical Disc Replacement With the BRYAN Cervical Disc: Results From a Prospective, Randomized, Controlled Clinical Trial [J]. Spine (Phila Pa 1976), 2019, 44(9): 601-8. ALAM I, SHARMA R, BORKAR S A, et al. Factors predicting loss of cervical lordosis following cervical laminoplasty: A critical review [J]. Journal of craniovertebral junction & spine, 2020, 11(3): 163-8. WEINBERG D S, RHEE J M. Cervical laminoplasty: indication, technique, complications [J]. Journal of spine surgery (Hong Kong), 2020, 6(1): 290-301. KIM B J, CHO S M, HUR J W, et al. Kinematics after cervical laminoplasty: risk factors for cervical kyphotic deformity after laminoplasty [J]. The spine journal : official journal of the North American Spine Society, 2021, 21(11): 1822-9. Han P . Comparison of surgical results and outcomes of posterior single-door cervical laminoplasty with 3-segment and 5-segment mini-titanium plate fixation [J]. The Journal of Cervicodynia and Lumbodynia, 2019, 40 (06): 762-765+769. YU Z, HE D, XIONG J, et al. Extensor muscle-preserving laminectomy in treating multilevel cervical spondylotic myelopathy compared with laminoplasty [J]. Annals of translational medicine, 2019, 7(18): 472. Li DY, Hai C, Liu YZ, et al. Clinical efficacy and cervical sagittal balance after posterior open-door laminoplasty with mini-plate and anchor[J]. Journal of Capital Medical University, 2019, 40 (04): 503-509. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4009212","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":276294754,"identity":"aa6157a0-5502-4283-833e-aaf599604668","order_by":0,"name":"Liang Ma","email":"","orcid":"","institution":"Sixth Afliated Hospital of Xinjiang Medical University, Orthopaedic Hospital of Xinjiang Uygur Autonomous Region","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Liang","middleName":"","lastName":"Ma","suffix":""},{"id":276294755,"identity":"24e25f2b-c047-4dfc-bfe3-738ee731c573","order_by":1,"name":"Xiangyu Meng","email":"","orcid":"","institution":"Sixth Afliated Hospital of Xinjiang Medical University, Orthopaedic Hospital of Xinjiang Uygur Autonomous Region","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xiangyu","middleName":"","lastName":"Meng","suffix":""},{"id":276294756,"identity":"72c7ad57-567c-4a95-8229-23fe09f2d635","order_by":2,"name":"Haiyan Xi","email":"","orcid":"","institution":"The Second Affiliated Hospital of the Naval Military Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Haiyan","middleName":"","lastName":"Xi","suffix":""},{"id":276294757,"identity":"85d3c023-246f-4261-b138-0b6ca82e7e7e","order_by":3,"name":"Abuduwupuer HAibier","email":"","orcid":"","institution":"Sixth Afliated Hospital of Xinjiang Medical University, Orthopaedic Hospital of Xinjiang Uygur Autonomous Region","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Abuduwupuer","middleName":"","lastName":"HAibier","suffix":""},{"id":276294758,"identity":"7d1d4287-483c-489e-8b91-088b226780d4","order_by":4,"name":"Changgui Shi","email":"","orcid":"","institution":"The Second Affiliated Hospital of the Naval Military Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Changgui","middleName":"","lastName":"Shi","suffix":""},{"id":276294759,"identity":"cd3de368-793e-49a0-83e7-07362fc4fd6a","order_by":5,"name":"Weibin Sheng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYDACCQY2ECXHwAyiDEjQYky6lsQGot1lcLv92YOPO2rTNxznPcD4o+COPAP74aMb8Gq5c8bccOaZ47kbDvMlMPMYPDNs4ElLu4FPi9mNHDZp3rZjuTObeQyYGQwOMzZI8JgR0JL+TPpv27F0SaAWxh8Gh+2J0JJgJs3YVpPAD3QVA4/B4USCWuzvnDGT7G07YNjPzJdwGKgluY2QXyRntz+T+NlWJ8/Gf/bgwx9/Dtv2sx8+hlcLFBwGYh6GAyAmGxHKQaAOrGUUjIJRMApGAVYAACLbSTat7dxOAAAAAElFTkSuQmCC","orcid":"","institution":"First Affiliated Hospital of Xinjiang Medical University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Weibin","middleName":"","lastName":"Sheng","suffix":""}],"badges":[],"createdAt":"2024-03-03 16:32:30","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4009212/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4009212/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":52183613,"identity":"b0e14abc-37d5-4f18-b978-54bba69d1942","added_by":"auto","created_at":"2024-03-07 18:13:59","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":262304,"visible":true,"origin":"","legend":"\u003cp\u003eA represents C2-7 SVA (red line); B represents C2-7 Cobb angle (red line); C represents C0-2 Cobb angle (red line); D represents T1-Slope (red line); E, F represent the difference in angle (red line) for the motion angle of C2/3 gap; G, H represent the difference (red line) for the displacement of C2 vertebral body; I, J represent the difference (red line) for ROM.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4009212/v1/cdf46d13a4101e942b6d256d.png"},{"id":52183609,"identity":"59cbcb34-db07-4c4b-9107-b1eb05b4fead","added_by":"auto","created_at":"2024-03-07 18:13:58","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":24840,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlow chart of test grouping\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4009212/v1/3abe2bad404b47965219d279.png"},{"id":52183612,"identity":"022da8af-943d-4b2a-a4d8-d37de1157e4e","added_by":"auto","created_at":"2024-03-07 18:13:59","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":33260,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eComparison of patient Neck ROM in the two treatment groups\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4009212/v1/e2c68f7737e8821ebab0f976.png"},{"id":52183610,"identity":"d0f56fce-29b6-409b-8a50-cb67373d3670","added_by":"auto","created_at":"2024-03-07 18:13:58","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":258162,"visible":true,"origin":"","legend":"\u003cp\u003eTypical case 1.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4009212/v1/126b46402031b0eb6db056bd.png"},{"id":52183611,"identity":"8a46d930-6be8-489c-b189-1bdcb00f5b7e","added_by":"auto","created_at":"2024-03-07 18:13:58","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":272549,"visible":true,"origin":"","legend":"\u003cp\u003eTypical case 1.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4009212/v1/e5da1e5981d1e7b1612fb7b5.png"},{"id":79839343,"identity":"ed8c65db-da3b-4af0-9235-d99c27ad29f9","added_by":"auto","created_at":"2025-04-03 12:16:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1925877,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4009212/v1/6049a22a-bfc4-4e0e-8503-2b6de3cba8b3.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The effects of C2 instability on cervical curvature changes and clinical outcomes after sub-axial cervical expansive door-open laminoplasty","fulltext":[{"header":"Introduction","content":"\u003cp\u003e\u0026nbsp;Multisegmental cervical spondylotic myelopathy (MCSM), cervical spinal stenosis, and ossification of the posterior longitudinal ligament (OPLL) are pathological changes that cause compression of the cervical spinal cord\u003csup\u003e[1]\u003c/sup\u003e. Patients often present with sensory and motor deficits in the limbs, as well as urinary and fecal dysfunction\u003csup\u003e[2]\u003c/sup\u003e. With changes in lifestyle, the incidence of these conditions has increased, significantly impacting patients' quality of life and being a major cause of disability.Posterior cervical expansive door-open laminoplasty (EODL) is a primary surgical approach for treating multisegmental cervical spinal cord compression\u003csup\u003e[3-4]\u003c/sup\u003e. EODL has been proven to have clear and long-lasting efficacy in improving patients' neurological function and relieving cervical spinal cord compression\u003csup\u003e[5]\u003c/sup\u003e. EODL is a non-fusion surgical technique that preserves cervical spine mobility to a certain extent. Moreover, EODL does not increase cervical instability in patients with pre-existing instability\u003csup\u003e[6]\u003c/sup\u003e. Additionally, EODL preserves the posterior column structures, effectively reducing surgical trauma and postoperative complications\u003csup\u003e[7]\u003c/sup\u003e. However, due to the extensive dissection of muscles, ligaments, and other structures during the procedure, there is a possibility of changes in sagittal parameters of the cervical spine, which may affect clinical outcomes or lead to postoperative axial pain\u003csup\u003e[8-9]\u003c/sup\u003e. The C2 vertebra plays a crucial role in measuring sagittal parameters of the cervical spine, as multiple parameters are measured with reference to the C2 vertebra. However, there is limited research on whether C2 vertebral instability affects the sagittal parameters and clinical outcomes of lower cervical spine EODL\u003csup\u003e[10]\u003c/sup\u003e. This study aims to retrospectively analyze the clinical and radiographic data of patients who underwent lower cervical spine EODL in our orthopedic department to evaluate the impact of C2 vertebral instability on sagittal parameters and clinical outcomes after EODL.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"1 Objects and methods Subjects and methods","content":"\u003cp\u003e\u003cstrong\u003e1.1General Information\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, the clinical data and follow-up records of patients undergoing cervical EODL in the first Affiliated Hospital of Naval Military Medical University from August 2017 to August 2021 were selected. The patients were divided into the cervical 2 vertebral instability group (observation group) and the cervical 2 vertebral stabilization group (control group), and the patients treated by EODL surgical treatment in the same time according to the age, gender and surgical segment matching (1:2). All patients signed the informed consent before surgery, and the study was approved by the hospital ethics committee.\u003cstrong\u003e1.2Inclusion criteria:\u0026nbsp;\u003c/strong\u003e(i) Presence of symptoms and signs of cervical spinal cord compression before surgery. (ii) Imaging showing evidence of Multisegmental Cervical Spondylotic Myelopathy (MCSM) or Ossification of Posterior Longitudinal Ligament (OPLL). (iii) Underwent lower cervical spine EODL surgery. (iiii) Follow-up for at least 2 years with complete imaging data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.3Exclusion criteria\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003e(i) Presence of cervical radiculopathy and concurrent radicular cervical spine disease. (ii) Concurrent posterior cervical pedicle screw-rod fixation or anterior cervical plate and screw fixation. (iii) History of previous cervical spine surgery or trauma. (iiii) Severe cervical kyphosis deformity or presence of cervical spine infection, tumor, etc. (iiiii) Concurrent rheumatoid arthritis or ankylosing spondylitis, and other related diseases.\u003c/p\u003e\n\u003cp\u003eAccording to the inclusion and exclusion criteria, a total of 18 patients were selected for the observation group, including 12 males and 6 females. The age ranged from 45 to 72 years, with an average age of (58.2\u0026plusmn;3.1) years. The body mass index (BMI) ranged from 18 to 27 kg/m2, with an average BMI of (23.8\u0026plusmn;2.3) kg/m2. The duration of the disease ranged from 5 to 14 months, with an average duration of (9.7\u0026plusmn;5.5) months. Two patients had concomitant hypertension, and one patient had diabetes. Among the patients, 8 underwent surgery at the C3-6 level, and 10 underwent surgery at the C3-7 level.The control group consisted of 36 matched patients, including 25 males and 11 females. The age ranged from 45 to 72 years, with an average age of (58.5\u0026plusmn;2.9) years. The body mass index (BMI) ranged from 17 to 28 kg/m2, with an average BMI of (23.5\u0026plusmn;2.1) kg/m2. The duration of the disease ranged from 6 to 13 months, with an average duration of (9.5\u0026plusmn;5.6) months. Three patients had concomitant hypertension, and two patients had diabetes. Among the patients, 26 underwent surgery at the C3-6 level, and 10 underwent surgery at the C3-7 level.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.4 Surgical method\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe patient is placed under general anesthesia and positioned prone on a plaster bed. The surgical field is prepared with routine disinfection and draping. A midline incision is made posterior to the neck, extending from the spinous processes of C2 to C7, with a length of 8-10cm. The skin, subcutaneous tissue, fascia, and nuchal ligament are dissected using an electric scalpel. The paraspinal muscles are then dissected bilaterally along the periosteum, exposing the area from the lower half of the C2 spinous process to the spinous processes and laminae of C3-6 or C3-7. Using a burr, slots are created at the junction of the lamina and lateral mass on the side with more compression, which serves as the \u0026quot;open-door\u0026quot; side. The laminae are thinned and removed bilaterally, deep to the spinal canal. On the side with less compression, known as the \u0026quot;hinge\u0026quot; side, the laminae are thinned and the ventral cortex is preserved. The laminae of C3-6 or C3-7 are sequentially lifted from caudal to cranial, and mini titanium plates (arch plates) are used to fixate the lateral mass and laminae on the open-door side. Any remaining bone in the inner edge of the lateral mass and intervertebral foramen area is carefully removed using rongeurs and curettes. Adhesions between the dura mater or nerve roots and the ligamentum flavum are released. Hemostasis is ensured throughout the procedure. After confirming satisfactory pulsation of the dura mater, the surgical site is irrigated with saline solution, and drainage is placed before closing the incision layer by layer. Postoperatively, the patient is instructed to wear a cervical collar for 2-3 weeks as per routine.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.5 Observed indicators\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(1) Measurement of sagittal parameters: Preoperative and postoperative cervical spine lateral, flexion-extension, CT, and MRI images are obtained. The PACS 3.0 system software is used to measure the following sagittal parameters on cervical X-ray images: C0-2 Cobb angle, C2-7 sagittal vertical axis (SVA) in millimeters, C2-7 Cobb angle, T1-Slope, range of motion (ROM) of the cervical spine, displacement of the C2 vertebral body (measured as the distance between the posterior edge of the C2 vertebral body and the posterior edge of the C3 vertebral body on flexion-extension X-ray images in millimeters), and the angle of motion at the C2/3 level (measured as the difference in angle at the C2/3 level on flexion-extension X-ray images). Two physicians independently measure the imaging parameters twice using the described method. The average value of the measurements is taken as the final measurement data. The assessors are blinded to the study content. Please refer to \u003cstrong\u003eFigure 1\u003c/strong\u003e for specific measurement methods.\u003c/p\u003e\n\u003cp\u003e(2) Clinical efficacy assessment: Preoperative and postoperative pain and neurological function improvement in patients are evaluated using the visual analog scale (VAS) for neck and shoulder pain and the Japanese Orthopaedic Association (JOA) score for cervical spine function. The improvement rate (%) is calculated as follows: Improvement rate (%) = (Postoperative JOA score - Preoperative JOA score) / (17 - Preoperative JOA score) \u0026times; 100%.\u003c/p\u003e\n\u003cp\u003e(3) Complications: Intraoperative and postoperative complications are recorded, including dural tear, nerve injury, postoperative C5 nerve root palsy, postoperative infection and hematoma, postoperative axial pain, failure of internal fixation, and re-closure.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.6\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eStatistical methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data were analyzed using SPSS 26.0 software. Continuous variables are presented as mean \u0026plusmn; standard deviation. Paired sample t-tests were used for within-group comparisons of preoperative and postoperative data, while independent sample t-tests were used for between-group comparisons. Categorical data were analyzed using chi-square tests or Fisher\u0026apos;s exact tests. The correlation between clinical efficacy and changes in imaging parameters was analyzed using Pearson correlation tests. A p-value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"2 Results","content":"\u003cp\u003e\u003cstrong\u003e2.1 Experimental flow chart The\u0026nbsp;\u003c/strong\u003eflow\u0026nbsp;chart of the two groupings\u0026nbsp;is shown in\u0026nbsp;\u003cstrong\u003eFigure\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure \u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2 Flow chart of test grouping\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Comparison of preoperative data between the two groups\u003c/strong\u003e：Baseline data on age, sex, body mass index, disease duration, surgical segment, follow-up time, operation time, bleeding volume, and complications were comparable (p\u0026gt; 0.05). See \u003cstrong\u003eTable 1\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1 Basic preoperative data of the two groups\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"110%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u003cstrong\u003eItems\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e\u003cstrong\u003eObservation group\u003c/strong\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003en=18\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e\u003cstrong\u003eControl group\u003c/strong\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003en=36\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\u003cstrong\u003e\u0026chi;\u003csup\u003e2\u003c/sup\u003e/Fisher\u0026apos;s exact test\u003c/strong\u003e\u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e58.2\u0026plusmn;3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e58.5\u0026plusmn;2.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.587\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.561\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSex\u003c/strong\u003e\u003cstrong\u003e(n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e12/6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e25/11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.468\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.494\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eDisease course (month)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e9.7\u0026plusmn;5.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e9.5\u0026plusmn;5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e1.563\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.134\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eFollow-up time (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e2.4\u0026plusmn;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e2.9\u0026plusmn;1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e1.509\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.141\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eBMI（kg/m\u003csup\u003e2\u003c/sup\u003e）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e23.8\u0026plusmn;2.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e23.5\u0026plusmn;2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e1.489\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.152\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eDiagnosis (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.139\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.933\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp; OPLL disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e6/33.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e10/27.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp;\u0026nbsp;Cervical spinal stenosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e10/56.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e22/61.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\u0026nbsp; Cervical herniated disc\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e2/11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e4/11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eSurgical segment \u0026nbsp;(n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.643\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.423\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp; C3-6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e8/44.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e26/72.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp; C3-7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e10/55.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e10/27.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eOperation time (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e112.2\u0026plusmn;3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e114.2\u0026plusmn;3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e1.595\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.120\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003ebleeding volume（ml）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e95.0\u0026plusmn;6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e97.5\u0026plusmn;4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e1.293\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.205\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003eComplication(n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp; Axial symptoms\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e3/16.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e2/5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.232\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.630\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp; Wound infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e0/0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e1/2.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.509\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.475\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"28.821656050955415%\"\u003e\n \u003cp\u003e\u0026nbsp; C5Nerve root paralysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.59235668789809%\"\u003e\n \u003cp\u003e1/5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.133757961783438%\"\u003e\n \u003cp\u003e3/8.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.853503184713375%\"\u003e\n \u003cp\u003e0.135\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.598726114649681%\"\u003e\n \u003cp\u003e0.713\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Neurological function assessment and vas scores \u0026nbsp;\u003c/strong\u003eDuring the postoperative follow-up, it was observed that the JOA score in the observation group improved from 7.5\u0026plusmn;1.2 preoperatively to 14.0\u0026plusmn;1.6 postoperatively, with an improvement rate of 68.42%. In the control group, the JOA score improved from 7.7\u0026plusmn;1.0 preoperatively to 13.1\u0026plusmn;1.6 postoperatively, with an improvement rate of 58.06%. There were no significant differences in JOA scores between the two groups at the last follow-up. It was also noted that the VAS scores for neck pain significantly decreased in both groups during the postoperative follow-up.See \u003cstrong\u003eTable 2\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eTable 2: neurological function assessment and vas scores\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"553\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003eItems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003eObservation group（n=18）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003eControl group（n=36）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e\u003cem\u003et\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003eNeck VAS score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003e7.3\u0026plusmn;0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003e7.3\u0026plusmn;0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e0.024\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e0.981\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003e1.1\u0026plusmn;0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003e1.0\u0026plusmn;0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e0.711\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e0.482\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003eJOA score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003e7.5\u0026plusmn;1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003e7.7\u0026plusmn;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e0.562\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e0.578\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"22.78481012658228%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.103074141048825%\"\u003e\n \u003cp\u003e14.0\u0026plusmn;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.305605786618443%\"\u003e\n \u003cp\u003e13.1\u0026plusmn;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.22242314647378%\"\u003e\n \u003cp\u003e1.870\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.584086799276673%\"\u003e\n \u003cp\u003e0.067\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Evaluation of radiographic parameters\u0026nbsp;\u003c/strong\u003eBefore the surgery, the cervical ROM was (39.8\u0026plusmn;3.6)\u0026deg; in the observation group and (36.3\u0026plusmn;4.3)\u0026deg; in the control group, with a statistically significant difference (P\u0026lt;0.05). At the last follow-up in the observation group, compared to preoperative values, the C0-2 Cobb angle increased from (22.0\u0026plusmn;3.7)\u0026deg; to (25.8\u0026plusmn;3.1)\u0026deg;; C2-7 SVA increased from (-19.6\u0026plusmn;3.4) mm to (-15.8\u0026plusmn;3.7) mm; C2-7 Cobb angle decreased from (8.2\u0026plusmn;0.1)\u0026deg; to (5.1\u0026plusmn;2.5)\u0026deg;; and cervical ROM decreased from (39.8\u0026plusmn;3.6)\u0026deg; to (31.6\u0026plusmn;4.5)\u0026deg;. All these parameters showed statistically significant differences within the observation group (P\u0026lt;0.05), while there was no significant difference in T1-Slope (P\u0026gt;0.05). In the control group, at the last follow-up compared to preoperative values, the C0-2 Cobb angle increased from (22.8\u0026plusmn;2.7)\u0026deg; to (25.3\u0026plusmn;2.9)\u0026deg;; C2-7 SVA increased from (-18.7\u0026plusmn;3.5) mm to (-15.3\u0026plusmn;1.4) mm; C2-7 Cobb angle decreased from (8.2\u0026plusmn;0.2)\u0026deg; to (4.9\u0026plusmn;0.8)\u0026deg;; and cervical ROM decreased from (36.3\u0026plusmn;4.3)\u0026deg; to (30.6\u0026plusmn;4.5)\u0026deg;. All these parameters showed statistically significant differences within the control group (P\u0026lt;0.05), while there was no significant difference in T1-Slope (P\u0026gt;0.05). There were no significant differences between the two groups in the above-mentioned parameters at the last follow-up compared to preoperative values (P\u0026gt;0.05) .See \u003cstrong\u003eTable 3\u003c/strong\u003e. In the observation group, at the last follow-up compared to preoperative values, the displacement of the C2 vertebral body decreased from (4.5\u0026plusmn;0.9) mm to (3.3\u0026plusmn;0.5) mm, which was statistically significant (P\u0026lt;0.05)，\u003cstrong\u003esee Figure3\u003c/strong\u003e, while the angle of motion at the C2/3 level decreased from (9.9\u0026plusmn;1.7)\u0026deg; to (8.6\u0026plusmn;2.5)\u0026deg;, but the difference was not statistically significant (P\u0026gt;0.05) .See \u003cstrong\u003eTable 4\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e: Sagittal Parameters of the Cervical Spine in the Two Groups of Patients\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"598\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eItems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003eObservation group（n=18）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003eControl group（n=36）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e\u003cem\u003et\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eC\u003csub\u003e0-2\u003c/sub\u003e Cobb（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e22.0\u0026plusmn;3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e22.8\u0026plusmn;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.716\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.479\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e25.8\u0026plusmn;3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e25.3\u0026plusmn;2.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e1.523\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.137\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eC\u003csub\u003e2-7\u003c/sub\u003e SVA（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e-19.6\u0026plusmn;3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e-18.7\u0026plusmn;3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.898\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.376\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e-15.8\u0026plusmn;3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e-15.3\u0026plusmn;1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.655\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.517\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eC\u003csub\u003e2-7\u003c/sub\u003e Cobb（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e8.2\u0026plusmn;0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e8.2\u0026plusmn;0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.451\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.655\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e5.1\u0026plusmn;2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e4.9\u0026plusmn;0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.440\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.687\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eT1-Slope（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e27.0\u0026plusmn;5.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e26.1\u0026plusmn;3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.616\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.542\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e26.4\u0026plusmn;2.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e26.0\u0026plusmn;2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.464\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.646\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eNeck ROM（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e39.8\u0026plusmn;3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e36.3\u0026plusmn;4.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e4.454\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.013\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.4247491638796%\"\u003e\n \u003cp\u003eThe last follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.929765886287626%\"\u003e\n \u003cp\u003e31.6\u0026plusmn;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.91973244147157%\"\u003e\n \u003cp\u003e30.6\u0026plusmn;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.695652173913043%\"\u003e\n \u003cp\u003e0.666\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.03010033444816%\"\u003e\n \u003cp\u003e0.510\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eFigure3 Comparison of patient Neck ROM in the two treatment groups\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4\u003c/strong\u003e Assessment of the degree of neck 2 instability in the observation group before surgery and at the last follow-up visit\u003c/p\u003e\n\u003cdiv align=\"Left\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"592\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"47.2972972972973%\"\u003e\n \u003cp\u003eItems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.216216216216218%\"\u003e\n \u003cp\u003ePreoperative\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.41216216216216%\"\u003e\n \u003cp\u003ePostoperative follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.783783783783784%\"\u003e\n \u003cp\u003e\u003cem\u003et\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.29054054054054%\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"47.2972972972973%\"\u003e\n \u003cp\u003eNeck 2 vertebral displacement value（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.216216216216218%\"\u003e\n \u003cp\u003e4.5\u0026plusmn;0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.41216216216216%\"\u003e\n \u003cp\u003e3.3\u0026plusmn;0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.783783783783784%\"\u003e\n \u003cp\u003e4.163\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.29054054054054%\"\u003e\n \u003cp\u003e0.020\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"47.2972972972973%\"\u003e\n \u003cp\u003eNeck 2 / 3 gap activity angle（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.216216216216218%\"\u003e\n \u003cp\u003e9.9\u0026plusmn;1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.41216216216216%\"\u003e\n \u003cp\u003e8.6\u0026plusmn;2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.783783783783784%\"\u003e\n \u003cp\u003e0.926\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.29054054054054%\"\u003e\n \u003cp\u003e0.351\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Complications\u003c/strong\u003e\u0026nbsp; In the observation group, 3 cases (16.67%) experienced postoperative axial pain, while in the control group, there were 2 cases (5.56%). One case in the observation group developed C5 nerve root palsy, while in the control group, 3 cases developed C5 nerve root palsy. All patients in both groups achieved recovery through conservative treatment. One case in the control group experienced postoperative wound infection (2.8%), while no infection cases were observed in the observation group. Neither group experienced cerebrospinal fluid leakage, nerve injury, failure of internal fixation, re-closure, or hinge fracture .See Table 5.\u003c/p\u003e\n\u003cp\u003e2.4 Relationship between Changes in Sagittal Parameters and Clinical Efficacy in the Observation Group The relationship between changes in sagittal parameters and clinical efficacy in the observation group is shown in Table 5. The improvement rate of neurological function was 68.42%. However, there was no significant correlation between changes in sagittal parameters and cervical range of motion (ROM) with clinical efficacy (P\u0026gt;0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5:\u003c/strong\u003e Relationship between Changes in Sagittal Parameters and Clinical Efficacy in the Observation Group\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"594\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.77777777777778%\"\u003e\n \u003cp\u003eItems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.902356902356902%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.63973063973064%\"\u003e\n \u003cp\u003eNeck 2 vertebral displacement value（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.993265993265993%\"\u003e\n \u003cp\u003eC2-7 Cobb（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.68686868686869%\"\u003e\n \u003cp\u003eNeck ROM（\u0026deg;）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.77777777777778%\"\u003e\n \u003cp\u003eNeck VAS score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.902356902356902%\"\u003e\n \u003cp\u003er\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.63973063973064%\"\u003e\n \u003cp\u003e0.199\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.993265993265993%\"\u003e\n \u003cp\u003e0.021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.68686868686869%\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.77777777777778%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.902356902356902%\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.63973063973064%\"\u003e\n \u003cp\u003e0.428\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.993265993265993%\"\u003e\n \u003cp\u003e0.901\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.68686868686869%\"\u003e\n \u003cp\u003e0.986\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.77777777777778%\"\u003e\n \u003cp\u003eRate of neurological improvement（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.902356902356902%\"\u003e\n \u003cp\u003er\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.63973063973064%\"\u003e\n \u003cp\u003e0.327\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.993265993265993%\"\u003e\n \u003cp\u003e0.128\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.68686868686869%\"\u003e\n \u003cp\u003e0.022\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.77777777777778%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.902356902356902%\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.63973063973064%\"\u003e\n \u003cp\u003e0.185\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.993265993265993%\"\u003e\n \u003cp\u003e0.612\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.68686868686869%\"\u003e\n \u003cp\u003e0.929\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote:cervical ROM is cervical mobility;neurological improvement rate:(postoperative JOA score-preoperative JOA score)/(17-preoperative JOA score) 100%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.\u003c/strong\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Typical cases\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCase 1, female patient, 50 years old. A, B are preoperative sagittal MRI images, showing varying degrees of disc protrusion at the C4/5, C5/6, and C6/7 levels. C, D are preoperative anterior-posterior X-rays, showing loss of cervical lordosis. E, F are preoperative flexion-extension X-rays, showing instability of the C2 vertebra. G, H are postoperative follow-up lateral X-rays, showing good position of the internal fixation. I, J are postoperative follow-up flexion-extension X-rays, showing no significant changes in the instability of the C2 vertebra.See\u003cstrong\u003e\u0026nbsp;Figure 4\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure 4\u003c/strong\u003e Typical case 1.\u003c/p\u003e\n\u003cp\u003eCase 2, male patient, 57 years old. A, B are preoperative sagittal MRI images, showing varying degrees of stenosis at the C3/4, C4/5, and C5/6 levels, with ossification of the posterior longitudinal ligament at C3/4. C, D are preoperative anterior-posterior X-rays, showing slight straightening of the cervical curvature. E, F are preoperative flexion-extension X-rays, showing instability of the C2 vertebra. G, H are postoperative follow-up lateral X-rays, showing good position of the internal fixation. I, J are postoperative follow-up flexion-extension X-rays, showing no significant changes in the instability of the C2 vertebra.See\u003cstrong\u003e\u0026nbsp;Figure 5\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure 5\u003c/strong\u003e Typical case 1.\u003c/p\u003e"},{"header":"3 Discussion","content":"\u003cp\u003eIn the 1970s, Hirabayashi et al. first reported the posterior cervical laminoplasty, which is now widely used for the treatment of MCSM, cervical spinal stenosis, and OPLL\u003csup\u003e[11-12]\u003c/sup\u003e. It has been proven to be a safe and effective surgical technique\u003csup\u003e[13]\u003c/sup\u003e. However, posterior cervical surgery inevitably causes damage to the muscles and ligaments in the posterior neck region, leading to changes in the normal cervical curvature, disruption of sagittal balance, and even the development of cervical kyphosis\u003csup\u003e[14-15]\u003c/sup\u003e. Postoperative cervical kyphosis has been observed in 6% to 46% of patients undergoing conventional laminoplasty procedures.In a study by Yang et al., they measured nine sagittal parameters in 164 patients who underwent cervical laminoplasty\u003csup\u003e[16-17]\u003c/sup\u003e. They found that the lower cervical curvature became straighter (decreased C2-7 Cobb angle) and the center of gravity of the head and neck shifted forward (increased C2-7 SVA). However, compensatory changes were observed in the upper cervical spine and cervicothoracic junction, such as increased cervical overextension (increased C0-2 Cobb angle, T1-Slope) to compensate for these changes\u003csup\u003e[18]\u003c/sup\u003e.Douglas et al. mentioned in their review that for patients with a significant increase in C2-7 SVA or head center of gravity SVA, alternative surgical techniques may be considered as a substitute for laminoplasty, even if there is spinal kyphosis\u003csup\u003e[19]\u003c/sup\u003e. During the C3 laminoplasty procedure, it is usually necessary to dissect the C2 lamina and the distal muscle tissue of the spinous process\u003csup\u003e[20]\u003c/sup\u003e. The posterior bony structures of C2 serve as attachment points for multiple muscles in the posterior head and neck region\u003csup\u003e[21]\u003c/sup\u003e. Excessive dissection and postoperative sagittal imbalance and axial pain may be related to this. The position of the C2 vertebra is of great significance in assessing sagittal balance of the cervical spine. However, most studies on cervical sagittal balance are based on the assumption of C2 vertebral stability\u003csup\u003e[22]\u003c/sup\u003e. In our study, we focused on the changes in cervical curvature and their clinical significance after EODL surgery, specifically considering the premise of C2 vertebral instability\u003csup\u003e[23]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe results of this study showed that at the last follow-up, both the observation group and the control group showed significant improvement in JOA scores (P\u0026lt;0.05), which is consistent with previous reports on the efficacy of EODL surgery. Furthermore, there was no significant difference in JOA improvement between the observation group and the control group, suggesting that the increased spinal canal space and improved spinal cord function after cervical laminoplasty are not affected by C2 vertebral instability\u003csup\u003e[24-26]\u003c/sup\u003e. Our study found that the degree of C2 vertebral instability did not worsen after surgery in the observation group, and in fact, there was a reduction in C2 vertebral displacement compared to preoperative values (P\u0026lt;0.05). This suggests that laminoplasty not only does not increase C2 vertebral instability but also tends to stabilize the overall cervical spine. This may be attributed to factors such as muscle scarring, ossification of the C2/3 joint capsule, and fusion of inflamed joint surfaces after surgery\u003csup\u003e[27-28]\u003c/sup\u003e. However, there was a decrease in cervical range of motion compared to preoperative values (P\u0026lt;0.05), indicating that although EODL surgery with C2 vertebral instability leads to a decrease in lower cervical range of motion, it does not affect the stability of the C2 vertebra.\u0026nbsp;Regarding cervical sagittal balance, there were no significant differences in C0-2 Cobb angle, C2-7 SVA, C2-7 Cobb angle, and T1-Slope between the two groups preoperatively. This may be because most patients in the observation group did not show obvious subluxation of the C2 vertebra in the lateral view, but instability was only evident in flexion-extension views\u003csup\u003e[29-31]\u003c/sup\u003e. Therefore, there were no significant differences in these parameters between the two groups in the preoperative lateral X-rays. However, the preoperative range of motion (ROM) of the cervical spine was greater in the observation group compared to the control group, and there was a significant difference (P\u0026lt;0.05). This is related to the increased mobility caused by C2 vertebral instability in the observation group.In both groups, postoperative follow-up showed a significant increase in C0-2 Cobb angle and C2-7 SVA, no significant difference in T1-Slope, and a significant decrease in C2-7 Cobb angle and cervical ROM\u003csup\u003e[32]\u003c/sup\u003e. This indicates an overall forward inclination of the cervical spine. However, there were no significant differences between the groups in the above-mentioned parameters (P\u0026gt;0.05). This is consistent with previous literature reporting that EODL surgery can lead to a straightening of the cervical curvature and even the development of significant kyphotic deformity due to the extensive disruption of the posterior cervical muscles. Cervical kyphosis is also a risk factor for poor postoperative outcomes in patients with cervical myelopathy\u003csup\u003e[33]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe correlation analysis between the changes in these imaging parameters and the clinical efficacy evaluation of the patients shows that the decrease in cervical curvature, reduction in C2 vertebral displacement, and decrease in cervical range of motion are not significantly correlated with the improvement in neck pain and neurological function in patients\u003csup\u003e[34]\u003c/sup\u003e. It can be observed that the postoperative efficacy in patients with MCSM is mainly related to thorough decompression of the spinal cord, rather than being significantly correlated with preoperative C2 vertebral instability\u003csup\u003e[35]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eIn conclusion, cervical laminoplasty results in a decrease in cervical range of motion (ROM) and stabilization of unstable vertebrae. Although it may not provide the same level of stability as screw fixation, it still contributes to the stability of the cervical spine. Therefore, C2 vertebral instability does not affect the sagittal parameters and clinical efficacy after laminoplasty, and it does not worsen C2 vertebral instability postoperatively. In patients with C2 vertebral instability, there is an increase in cervical range of motion, but after laminoplasty, the range of motion decreases and tends to stabilize. Cervical laminoplasty is a good treatment option for MCSM. However, it is important to note that this study had a small sample size and was retrospective in nature. Further prospective studies with larger sample sizes and longer follow-up periods are needed to further investigate this topic.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eMCSM\u0026nbsp;=\u0026nbsp;Multisegmental cervical spondylotic myelopathy\u003c/p\u003e\n\u003cp\u003eOPLL\u0026nbsp;=\u0026nbsp;Ossification of the posterior longitudinal ligament\u003c/p\u003e\n\u003cp\u003eEODL\u0026nbsp;=\u0026nbsp;Posterior cervical expansive door-open laminoplasty\u003c/p\u003e\n\u003cp\u003eJOA\u0026nbsp;=\u0026nbsp;Japanese Orthopaedic Association\u003c/p\u003e\n\u003cp\u003eVAS =\u0026nbsp;Visual analogue scale\u003c/p\u003e\n\u003cp\u003eBMI = Body mass index\u003c/p\u003e\n\u003cp\u003eROM\u0026nbsp;=\u0026nbsp;Range of motion \u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy design, conception, and critical revision:\u0026nbsp;Liang Ma\u0026nbsp;and\u0026nbsp;Weibin Sheng. Analysis and interpretation of data:\u0026nbsp;Haiyan Xi\u0026nbsp;and\u0026nbsp;Abuduwupuer HAibier. Literature search and drafting of manuscript:\u0026nbsp;Changgui Shi\u0026nbsp;and\u0026nbsp;Liang Ma\u0026nbsp;contributed to critical revision of the manuscript for important intellectual content and approved the fnal version of the manuscript. All authors read and approved the fnal version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate the impact of C2 vertebral instability on the sagittal parameters of the cervical spine and the clinical efficacy after cervical laminoplasty with unilateral open-door cervical expansive laminoplasty (EMOL).Because part of the data is incomplete , so the dataset analyzed in this study is not publicly available but is available to the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe confrm that all experiments were performed in accordance with the Declaration of Helsinki. The study was approved by the Ethical Committee of the Sixth Afliated Hospital of Xinjiang Medical University. Each patient provided written informed consent before participating in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eDepartment of Orthopedics of Spine, Sixth Afliated Hospital of Xinjiang Medical University, Orthopaedic Hospital of Xinjiang Uygur Autonomous Region, No.39 Wuxing Road, Urumqi, People\u0026rsquo;s Republic of China. \u003csup\u003e2\u003c/sup\u003eXinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, People\u0026rsquo;s Republic of China.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eWANG W X, ZHAO Y B, LU X D, et al. 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BMC Musculoskelet Disord, 2021, 22(1): 426.\u003c/li\u003e\n\u003cli\u003eQi M, Chen HJ, Liu Y, et al. Laminoplasty with selective fusion in the treatment of cervical ossification of the posterior longitudinalligament with local instability[J]. Chinese Journal of Spine and Spinal Cord, 2020, 30 (03): 219-226.\u003c/li\u003e\n\u003cli\u003ePan YB. The Research Progress of Posterior Open-door Laminoplasty and Sagittal Balance of Cervical Spine[D]. World Latest Medicine Information (Electronic Version), 2020. DOI:10.27288/d.cnki.gsxyu.2020.000583.\u003c/li\u003e\n\u003cli\u003eKATO M, NAMIKAWA T, MATSUMURA A, et al. Effect of Cervical Sagittal Balance on Laminoplasty in Patients With Cervical Myelopathy [J]. Global spine journal, 2017, 7(2): 154-61.\u003c/li\u003e\n\u003cli\u003eKWOK S S S, CHEUNG J P Y. Surgical decision-making for ossification of the posterior longitudinal ligament versus other types of degenerative cervical myelopathy: anterior versus posterior approaches [J]. BMC Musculoskelet Disord, 2020, 21(1): 823.\u003c/li\u003e\n\u003cli\u003eLI X Y, WANG Y, ZHU W G, et al. Impact of cervical and global spine sagittal alignment on cervical curvature changes after posterior cervical laminoplasty [J]. J Orthop Surg Res, 2022, 17(1): 521.\u003c/li\u003e\n\u003cli\u003eQIAN S, WANG Z, JIANG G, et al. Efficacy of Laminoplasty in Patients with Cervical Kyphosis [J]. Med Sci Monit, 2018, 24: 1188-95.\u003c/li\u003e\n\u003cli\u003eYang P, Wen BT, Ge ZL, et al. Sagittal alignment changes of cervical spine in patients with cervical spondylotic myelopathy aftercervical 3-7 single-door laminoplasty and its correlation with functional status of cervical spinel[J]. Chinese Journal of Spine and Spinal Cord, 2020, 30 (02): 123-129.\u003c/li\u003e\n\u003cli\u003eONO K, MURATA S, MATSUSHITA M, et al. Cervical Lordosis Ratio as a Novel Predictor for the Loss of Cervical Lordosis After Laminoplasty [J]. Neurospine, 2021, 18(2): 311-8.\u003c/li\u003e\n\u003cli\u003ehen YY, Zou XB, Ma XY, et al. Comparison of cervical motion range and curvature after C3 laminectomy and mini-titanium plate fixation after single-door vertebroplasty [J]. Zhongguo Zuzhi Gongcheng Yanjiu, 2020, 24 (12): 1805-1809.\u003c/li\u003e\n\u003cli\u003eWIGUNA I, MAGETSARI R, NOOR Z, et al. Comparative Effectiveness and Functional Outcome of Open-Door versus French-Door Laminoplasty for Multilevel Cervical Myelopathy: A Meta-Analysis [J]. Open access Macedonian journal of medical sciences, 2019, 7(19): 3348-52.\u003c/li\u003e\n\u003cli\u003eLAVELLE W F, RIEW K D, LEVI A D, et al. Ten-year Outcomes of Cervical Disc Replacement With the BRYAN Cervical Disc: Results From a Prospective, Randomized, Controlled Clinical Trial [J]. Spine (Phila Pa 1976), 2019, 44(9): 601-8.\u003c/li\u003e\n\u003cli\u003eALAM I, SHARMA R, BORKAR S A, et al. Factors predicting loss of cervical lordosis following cervical laminoplasty: A critical review [J]. Journal of craniovertebral junction \u0026amp; spine, 2020, 11(3): 163-8.\u003c/li\u003e\n\u003cli\u003eWEINBERG D S, RHEE J M. Cervical laminoplasty: indication, technique, complications [J]. Journal of spine surgery (Hong Kong), 2020, 6(1): 290-301.\u003c/li\u003e\n\u003cli\u003eKIM B J, CHO S M, HUR J W, et al. Kinematics after cervical laminoplasty: risk factors for cervical kyphotic deformity after laminoplasty [J]. The spine journal : official journal of the North American Spine Society, 2021, 21(11): 1822-9.\u003c/li\u003e\n\u003cli\u003eHan P . Comparison of surgical results and outcomes of posterior single-door cervical laminoplasty with 3-segment and 5-segment mini-titanium plate fixation [J]. The Journal of Cervicodynia and Lumbodynia, 2019, 40 (06): 762-765+769.\u003c/li\u003e\n\u003cli\u003eYU Z, HE D, XIONG J, et al. Extensor muscle-preserving laminectomy in treating multilevel cervical spondylotic myelopathy compared with laminoplasty [J]. Annals of translational medicine, 2019, 7(18): 472.\u003c/li\u003e\n\u003cli\u003eLi DY, Hai C, Liu YZ, et al. Clinical efficacy and cervical sagittal balance after posterior open-door laminoplasty with mini-plate and anchor[J]. Journal of Capital Medical University, 2019, 40 (04): 503-509.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"lower cervical vertebra, Cervical spondylotic myelopathy, Single door enlarged spinal canal plasty, Sagittal plane balance, Cervical instability","lastPublishedDoi":"10.21203/rs.3.rs-4009212/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4009212/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective:\u003c/strong\u003e To investigate the impact of C2 vertebral instability on the sagittal parameters of the cervical spine and the clinical efficacy after cervical laminoplasty with unilateral open-door cervical expansive laminoplasty (EMOL).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e In a retrospective analysis of 18 patients with cervical 2 vertebral instability from August 2017 to August 2021 in the second Affiliated Hospital of Naval Military Medical University and the first Affiliated Hospital of Xinjiang Medical University treated with single open-door vertebroplasty (C3-6 or C3-7), 36 patients with stable cervical 2 cervical EMOL during the same period (control group). To evaluate the changes in sagittal parameters before and after surgery in the two groups, including C0-2 Cobb angle, C2-7 sagittal axis distance (sagittal vertical axis, SVA), C2-7 Cobb angle, T1 tilt angle (T1-Sl); The postoperative outcome was evaluated using the visual analogue score for neck and shoulder pain (visual analog scale, VAS) and the Japan Society Cervical Function Score (Japanese 0rthopaedic Association, JOA).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Compared to preoperative values, both the observation group and the control group showed significant improvement in postoperative VAS scores and JOA scores. The JOA scores were 14.0±1.6 and 13.1±1.6, with improvement rates of 68.42% and 58.06%, respectively, compared to their respective preoperative scores. However, there was no significant difference between the two groups. The observation group had significantly greater cervical range of motion (ROM) before surgery compared to the control group (p\u0026lt;0.05).\u003c/p\u003e\n\u003cp\u003eAt the last follow-up, the observation group showed a significant decrease in C2-7 Cobb angle from preoperative (8.2±0.1)° to (5.1±2.5)° (p\u0026lt;0.05). Cervical ROM decreased from preoperative (39.8±3.6)° to (31.6±4.5)° (p\u0026lt;0.05). C0-2 Cobb angle increased from preoperative (22.0±3.7)° to (25.8±3.1)° (p\u0026lt;0.05). C2-7 SVA increased from preoperative (-19.6±3.4)° to (-15.8±3.7)° (p\u0026lt;0.05). However, there was no significant change in T1 slope at the last follow-up (p\u0026gt;0.05). The observation group showed a decrease in C2 vertebral displacement from preoperative (4.5±0.9) mm to (3.3±0.5) mm (p\u0026lt;0.05), while the C2/3 angle showed no significant change compared to preoperative values (p\u0026gt;0.05).\u003c/p\u003e\n\u003cp\u003eIn both groups, postoperative follow-up showed a significant increase in C0-2 Cobb angle and C2-7 SVA, a non-significant difference in T1 slope, and a significant decrease in C2-7 Cobb angle and cervical ROM compared to preoperative values. However, there were no significant differences between the two groups in the above-mentioned parameters (p\u0026gt;0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eC2 vertebral instability does not affect the sagittal parameters and efficacy of cervical laminoplasty with EMOL. EMOL surgery for cervical myelopathy with C2 vertebral instability is effective and reliable, without exacerbating C2 vertebral instability. Furthermore, it maintains good sagittal balance of the cervical spine.\u003c/p\u003e","manuscriptTitle":"The effects of C2 instability on cervical curvature changes and clinical outcomes after sub-axial cervical expansive door-open laminoplasty","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-07 18:13:54","doi":"10.21203/rs.3.rs-4009212/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a6c93366-5f16-46be-82f8-4c591db728d0","owner":[],"postedDate":"March 7th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-04-03T12:08:39+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-07 18:13:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4009212","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4009212","identity":"rs-4009212","version":["v1"]},"buildId":"omnImTCwR2MFx8CMYfrG7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}