C2-7 Cobb Angle Research Articles

Impact of the K-line in patients withossification of the posterior longitudinal ligament: Analysis of sagittal cervical curvature changes and surgical outcomes.

This study aimed to investigate the relationship of the K-line with sagittal cervical curvature changes and surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL). We retrospectively reviewed 84 patients with OPLL who underwent posterior cervical single-door laminoplasty. The patients were divided into a K-line-positive (+) group and a K-line-negative (-) group. Perioperative data, radiographic parameters, and clinical outcomes were compared between the two groups. Of 84 total patients, 50 patients were in the K (+) group and 29 patients were in the K (-) group. Neurological function improved in both groups after laminoplasty. The C2-7 Cobb angle, T1 slope, and C2-7 sagittal vertical axis were significantly changed in the K(-) group compared with those in the K (+) group before the operation and at the 3-month and final follow-ups. Neurological function was recovered in both groups, and the clinical effect on the K (+) group was better than that on the K (-) group. The cervical curvature in patients with OPLL tends to be anteverted and kyphotic after laminoplasty and is an important factor in reducing the clinical effect.

Effect of Anterior Cervical Decompression Fusion and Partial Resection of Uncinate Vertebra Joint on Cervical Sagittal Sequence in Patients with Non-Single-Segment Radiculopathy and its Correlation with Curative Effect: A Retrospective Analysis.

Analyze the effect of preservation or resection of the partial uncinate joint on the sagittal sequence of the cervical vertebrae in patients with non-single-segment radiculopathy and the correlation between the sagittal sequence of the cervical vertebrae and the long-term effect after surgery, we explored whether it is necessary to perform partial resection of the uncinate joint in patients with cervical spondylotic radiculopathy undergoing anterior cervical decompression and fusion (ACDF). The study retrospectively analyzed 96 patients with cervical spondylotic radiculopathy with more than two segments from August 2016 to January 2021, who underwent ACDF (ACDF group, 45 patients) or ACDF combined with partial uncinate joint resection (ACDF + UT group, 51 patients). Partial resection of the uncinate joint indicated removal of part of the uncinate joint and osteophyte based on the compression of the nerve root during surgery, whereas the uncinate joints in the ACDF group were retained completely. The imaging data and functional scores of the two groups were recorded before surgery, 1 month after surgery, and at the last follow-up. A paired t-test or rank sum test was applied to analyze the data. In addition, the correlation between the imaging parameters and functional scores was validated using the Pearson's test. All 96 patients successfully completed the surgery and were followed up for at least 12months, with an average follow-up time of 14months. At the last follow-up, the pain visual analog scale (VAS), neck disability index (NDI), and neck pain and disability scale (NPAD) scores of the two groups were significantly lower than those before surgery, and the Japanese Orthopaedic Association (JOA) score was significantly higher than that before surgery. At the last follow-up, compared with the ACDF+UT group, the NDI and NPAD scores in the ACDF group decreased more significantly (p < 0.05), and C2-7SVA, △C2-7SVA (the difference between C2-7 SVA at last follow-up and before operation), and T1S values decreased significantly (p < 0.05). The C2-7 Cobb angle was positively correlated with the JOA score and T1S (p < 0.05) and negatively correlated with the VAS, NDI, and NPAD scores and CGH-C7SVA (p < 0.05). C2-7SVA was positively correlated with CGH-C7SVA and T1S (p < 0.05). Patients with non-single-segmental cervical spondylotic radiculopathy and ACDF with or without uncinate joint resection can have effective improvement in the clinical effect and sagittal balance; however, partial uncinate joint resection has a certain negative impact on the long-term reconstruction of sagittal balance and long-term effects in patients after surgery.

Anterior and Posterior Approaches for 4-Level Degenerative Cervical Myelopathy: Low-Profile Cage Versus Cervical Pedicle Screws Fixation.

(1) Background: The choice of surgical access for 4-level degenerative cervical myelopathy (DCM) remains controversial, and the clinical and radiological outcomes of anterior surgery using a low-profile cage (Low-P) versus posterior surgery using cervical pedicle screw fixation (CPS) have not been compared. (2) Methods: This is a retrospective controlled study conducted between January 2019 and June 2021 of 72 patients with 4-level DCM who underwent ACDF using a low-profile cage (n = 39) or laminectomy and instrument fusion using CPS (n = 33). The minimum follow-up time was 12 months. The outcomes were C2-7Cobb angle, C2-7sagittal vertical axis (SVA) fusion rate, the Japanese Orthopedic Association (JOA) score, pain visual analog scale (VAS), neck disability index (NDI), and complications. (3) Results: Both anterior and posterior procedures significantly improved the patients' quality-of-life parameters. Anterior cervical convexity and SVA significantly increased in both groups, but the SVA was greater in the posterior group than in the anterior group (p &lt; 0.001). The C2-7 Cobb angle significantly improved in both groups postoperatively, and at the final follow-up, there was a slight but nonsignificant reduction in cervical lordosis in both groups (p = 0.567). There was a longer operative time, less intraoperative blood loss, and reduced mean hospital stay in the anterior group compared to the posterior group, with two cases of postoperative hematoma requiring a second operation, two cases of axial pain (AP), five cases of dysphagia, two cases of c5 palsy in the anterior group, and four cases of axial pain, and three cases of c5 palsy in the posterior group. According to Bridwell fusion grade, anterior fusion reached grade I in 28 cases (71.8%) and grade II in 10 cases (25.6%) in the anterior group, and posterior fusion reached grade I in 25 cases (75.8%) and grade II in 8 cases (24.2%) in the posterior group. (4) Conclusions: There was no difference between the anterior and posterior surgical approaches for MDCM in terms of improvement in neurological function. Posterior surgery using CPS achieved similar recovery of cervical anterior convexity as anterior surgery with a shorter operative time but was more invasive and had a greater increase in SVA. The use of Low-P in anterior surgery reduced the incidence of dysphagia and cage subsidence and was less invasive, but with a longer operative time.

Analysis of Components of Upper Cervical Lordosis in Asymptomatic Lordotic and Kyphotic Subjects

Upper cervical lordosis (CL) can be divided into 2 components: C2 slope (C2S) and McGregor slope (MGS) or C0-1 and C1-2 angles. The aim of this study was to investigate the components of upper CL in asymptomatic kyphotic and lordotic subjects. CL, C0-2 Cobb angle, MGS, C2S, C1 Slope, C0-1 Cobb angle, C1-2 Cobb angle, T1 slope angular parameters, and the C2-7 sagittal vertical axis distance of 78 asymptomatic subjects were measured. Sixty subjects had lordotic curvature and 18 had kyphotic curvature. There was a significant difference between the kyphotic and lordotic groups in all parameters, except for C0-1 Cobb angle and C2-7 sagittal vertical axis. In lordotic subjects, MGS and C2S accounted for 58% and 42% of the C0-2 angle, whereas in kyphotic subjects, 86% of C0-2 was accounted for by C2S. There was a strong negative correlation between C2S and MGS. In asymptomatic subjects, as CL decreases, MGS decreases, C2S increases, and the C0-2 angle turns down on the horizontal plane to maintain the horizontal gaze. Turning down the C0-2 angle is more important than its value for maintaining horizontal gaze; thus, the slopes (MGS and C2S) can better represent the upper and lower cervical alignment than angle values can. The relationship between upper and lower cervical alignment should be evaluated in terms of slope angles rather than simple angles. The lack of significant difference between the C0-1 angles in the kyphotic and lordotic groups suggests that only the C1-2 angle is involved in the compensatory mechanism for the horizontal gaze.

Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes.

Laminoplasty is a common and effective surgery for decompression of the spinal cord in multilevel cervical myelopathy. The midline splitting technique (MST) and the unilateral open door technique (UODT) are the two most commonly performed laminoplasty techniques with continuous debate on which is preferable. This study aimed to add light to the matter by comparing and exploring the possible causes of different outcomes. A total of 101 patients who underwent laminoplasty for degenerative cervical myelopathy were included in this study. Radiographic measurements including C2-7 Cobb angle, C2-7 range of motion (ROM), Pavlov ratio of the most compressed level, and canal area with diameter were compared. Modified Japanese Orthopedic Association (mJOA) score and complications including C5 palsy, axial neck pain, hinge fractures, and spacer displacement were also compared. Statistical analysis was performed using independent samples t-test, chi-square test, Fisher's exact test, and linear mixed model. C2-7 ROM, canal diameter, Pavlov ratio, and mJOA score did not demonstrate differences between the two techniques. The UODT group had greater postoperative canal expansion but had more loss of C2-7 lordosis than did the MST group. Of the complications, hinge fractures were more common in the UODT group, with more loss of C2-7 lordosis in patients with hinge fractures. On the other hand, spacer displacement occurred only in the MST group, with lesser canal expansion in patients with spacer displacement. The two laminoplasty techniques both demonstrated effectiveness in treating patients with multilevel cervical myelopathy. However, care should be given to avoid hinge fractures and spacer displacement since both can possibly lead to unfavorable outcomes.

Extension of decompression to C2 doesn’t affect the spinal sagittal parameters compared with standard open-door laminoplasty

We modified and extended laminoplasty to the upper cervical spine on patients with canal stenosis associated with upper cervical spinal ossified lesions. However, whether the extended decompression range of laminoplasty can cause further effects on cervical stability is rarely studied at present. A retrospective study to analyze the relationship between the surgical levels and cervical sagittal parameters effects was performed in patients with cervical spondylosis myelopathy who had undergone posterior cervical expansive open-door laminoplasty with/without extending to C2. In total, 64 patients were divided into 2 groups according to the surgical levels. Radiologic outcomes of occipito-cervical angle (C0-2 Cobb angle), CL C27 Cobb angle, cervical sagittal vertical alignment, T1-Slope (T1S), T1S minus CL (T1S-CL), spino-cranial angle and center of the sella turcica-C7 SVA (St-SVA) were evaluated on lateral X-rays of the cervical spine at pre-operation, post-operation, and 2-year follow-up. The patient's health-related quality of life was obtained including neck disability index, Japanese orthopaedic association scores, and visual analog scale. Changes in sagittal parameters were observed in both groups after surgery. T1S, cervical sagittal vertical alignment, and T1S-CL significantly increased and CL decreased in 2 groups of patients postoperative. After a 2-year follow-up period, the C0-2 Cobb angle was found to increase compared to preoperative records. In addition, there were no significant differences in spino-cranial angle and st-SVA between preoperative and 2 years follow-up measurements. Health-related quality of life was improved in both groups and was not significantly different. Herein, the parameters indicated a tilting forward of the lower cervical spine and a more lordotic upper cervical spine to maintain a horizontal gaze in patients. However, C2 to 7 laminoplasty was performed to achieve satisfactory clinical results without significantly changing the spinal sagittal parameters.

Efficacy of Anterior Cervical Discectomy and Fusion for Female Patients with Hirayama Disease

To compare the preoperative and postoperative hand function and radiographic parameters in female patients with HD. Consecutive female patients with HD undergoing anterior cervical discectomy and fusion were followed-up. The postoperative hand functional data were obtained from the last follow-up, while the postoperative radiographic data were obtained from the examinations in 3- or 6-month follow-up after surgical treatments. The preoperative and postoperative data of hand functional and radiographic assessments were collected and compared between them. Logistic regression analysis was used to clear potential risk factors for surgical treatment. In all, 15 female patients with HD were included in the follow-up study over 9 years. Significant differences were found in total scores (P<0.001) and all five dimensions, including function (P=0.003), activities of daily life (P=0.002), work (P=0.003), satisfaction (P=0.002), appearance (P=0.005), and HD-specific hand symptoms (P=0.001) in hand functional assessment. The comparison of C2-7 Cobb angle was statistically different (P=0.042) in radiographic assessments. The course of illness was of marginal significance (P=0.065) with curative effect of surgical treatment in logistic regression analysis. Anterior cervical discectomy and fusion was an effective way to treat female patients with HD, and the course of illness may be correlated with the efficacy of surgery. For some female patients with HD with a clear diagnosis, early surgical treatment is worthy of clinical consideration.

Cervical alignment and clinical outcome of anterior decompression with fusion vs. posterior decompression with fixation in kyphotic cervical spondylotic myelopathy.

Cervical kyphosis is a common but potentially debilitating and challenging condition. There is controversy on the optimal surgical strategy for the treatment of kyphotic cervical spondylotic myelopathy (KCSM) using either anterior approach or posterior approach. The purpose of this study was to investigate the surgical efficacy of anterior decompression with fusion (ADF) vs. posterior decompression with fixation (PDF) for the treatment of KCSM, and to further analyze the changes of cervical spinal alignment parameters and axial symptoms (AS) severity after kyphotic correction. We retrospectively reviewed 117 patients with KCSM who had undergone ADF (58 patients) and PDF (59 patients) between January 2016 and December 2020. Cervical spinal alignment parameters, including curvature index (CI) and C2-7 Cobb angle, were measured on the PreOP and PostOP lateral radiographs. Recovery rate was calculated based on the Japanese Orthopedic Association (JOA) score. AS severity was quantified by Neck Disability Index (NDI). A P-value less than 0.05 was considered to be significant. The patient mean age, gender, presenting symptoms and follow-up time were similar between the two groups (P > 0.05). However, there were statistically significant differences (P < 0.001) between the two groups regarding the operation levels, operating time and intraoperative blood loss. Analysis of PostOP follow-up data showed significant differences (P < 0.001) in CI, correction of CI, C2-7 Cobb angle, and NDI between the two groups, whereas no significant differences in JOA score (P = 0.16) and recovery rate (P = 0.14). There were significant differences (P < 0.001) in CI, C2-7 Cobb angle, JOA score, and NDI between PreOP and PostOP follow-up in each group. Correction of CI showed positive correlation with recovery of NDI in Group ADF (r = 0.51, P < 0.001), and in Group PDF (r = 0.45, P < 0.001). Satisfied neurological improvement was obtained by ADF and PDF for patients with KCSM. Cervical kyphotic correction caused significant improvement of AS, and was more favorable with ADF than with PDF. Surgeons should pay full consideration of the merits and shortcomings of each approach when deciding on a surgical plan.

Is the Zero-P Spacer Suitable for 3-Level Anterior Cervical Discectomy and Fusion Surgery in Terms of Sagittal Alignment Reconstruction: A Comparison Study with Traditional Plate and Cage System.

The Zero-P spacer was primarily developed aiming to reduce the morbidity associated with the traditional anterior cervical plate. During the past decade, many authors have reported the use of Zero-P spacers for anterior cervical discectomy and fusion (ACDF) of one or two segments. Nevertheless, there is still a paucity of knowledge on the safety and feasibility of using Zero-P spacers for 3-level fixation. The objective of this study was to investigate the clinical and radiological outcomes, with a focus on the sagittal alignment reconstruction of 3-level ACDF surgery using Zero-P spacers versus those using a traditional plate and cage system. From Sep 2013 to Aug 2016, a total of 44 patients who received 3-level ACDF surgery due to cervical spondylotic myelopathy were recruited. The Zero-P spacer was used in 23 patients (group ZP) and the traditional plate and cage system in 21 (group PC). Clinical outcomes were analyzed by Neck Disability Index (NDI) and Japanese Orthopedic Association (JOA) scores, and dysphagia was evaluated using the Bazaz score. Radiological outcomes, including fusion rate, adjacent segment degeneration (ASD), and especially changes in cervical sagittal alignment, were analyzed. The NDI and JOA scores did not differ significantly between the two groups postoperatively (p &gt; 0.05); however, there was significantly less dysphagia in patients using Zero-P spacers at the 3- and 6-month follow-up (p &lt; 0.05). At the 24-month follow-up, the fusion rate and ASD were similar between the two groups (p &gt; 0.05). Interestingly, patients using Zero-P spacers had a significantly lower postoperative C2-7 Cobb angle and fused segment Cobb angle, compared to those using a traditional plate and cage system (p &lt; 0.05); meanwhile, the fused segment disc wedge was also found to be significantly smaller in patients using Zero-P spacers after surgery (p &lt; 0.05). Moreover, we further divided patients into subgroups according to their cervical lordosis. In patients with a preoperative C2-7 Cobb angle ≤ 10°, significantly less cervical and local lordosis, as well as disc wedge, were seen in group ZP after surgery (p &lt; 0.05), while in others with a preoperative C2-7 Cobb angle &gt; 10°, no significant difference in postoperative changes of the cervical sagittal alignment was seen between group ZP and group PC (p &gt; 0.05). Zero-P spacers used in 3-level ACDF surgery could provide equivalent clinical outcomes and a lower rate of postoperative dysphagia, compared to the traditional plate and cage system. However, our results showed that it was inferior to the cervical plate in terms of sagittal alignment reconstruction for 3-level fixation. We recommend applying Zero-P spacers for 3-level ACDF in patients with good preoperative cervical lordosis (C2-7 Cobb angle &gt; 10°), in order to restore and maintain physiological curvature of the cervical spine postoperatively.

Validity and reliability of a novel iPhone method to rapidly measure cervical sagittal parameters

We introduced a novel method based on the iPhone’s intrinsic photo edit function to measure sagittal parameters of the cervical spine. This study aimed to assess the validity of this new method compared with the picture archiving and communication system (PACS) method (the gold standard) and to test the reliability of this novel technique. One hundred consecutive patients admitted to our hospital diagnosed with cervical spondylotic myelopathy or cervical spondylotic radiculopathy were retrospectively reviewed. Four angles, including the C0-2 Cobb angle, C2-7 Cobb angle, T1S and neck tilt (NT), were assessed by iPhone and PACS. The validity and reliability were evaluated, and the time taken by both methods was compared. The ICCs of the validity of the C0-2 Cobb angle, C2-7 Cobb angle, T1S and NT were 0.960, 0.976, 0.980 and 0.946, respectively. The ICCs of the intraobserver reliability of the C0-2 Cobb angle, C2-7 Cobb angle, T1S and NT were 0.966, 0.983, 0.971 and 0.951, respectively. The ICCs of the interobserver reliability of the C0-2 Cobb angle, C2-7 Cobb angle, T1S and NT were 0.953, 0.972, 0.957 and 0.929, respectively. The Bland‒Altman plot of validity of the four angles revealed mean differences of 0.3, 0.2, 0.1, and 0.1 degrees with 95% CIs of 4.1, 4.1, 2.9, and 4.3 degrees, respectively. The iPhone measurement time (58.55 ± 4.17 s) was significantly less than that by the PACS (70.40 ± 2.92 s) when compared by the independent-samples T test (P < 0.001). This novel method using the iPhone’s intrinsic photo edit function is accurate, reliable, fast and convenient when measuring cervical sagittal parameters.

Analysis of risk factors for postoperative dysphagia after C1-2 fusion.

ObjectiveThis study aimed to analyze the risk factors for dysphagia after C1-2 fusion in patients with C1-2 junction diseases.Summary of the background dataDysphagia is a common postoperative complication of posterior C1-2 junction surgery. The incidence is 9.5% to 26.3%. However, the etiopathogenisis of postoperative dysphagia remains controversial.MethodsThis retrospective study included patients who underwent C1-2 fusion from January 2016 to January 2020. The patients were divided into dysphagia group and control group in accordance with the Bazaz R dysphagia scoring system. The patients' age, gender, BMI(body mass index), cause of disease, and changes in the C01cobb, C02cobb, C12cobb, C27cobb, dC02cobb, dC01cobb, dC12cobb, d C27cobb angles before and after operation, were recorded. The parameters and changes were compared to analyze the risk factors for dysphagia after C1-2 fusion.Results65 cases (15, with dysphagia; 50, without dysphagia) were included. The incidence of postoperative dysphagia was 23%. The differences in age, gender ratio, and BMI between the two groups were not significant (P > 0.05). The differences among postoperative C12 (29.8° ± 11.24° vs. 20.46° ± 13.39°), postoperative C27cobb (10.56° ± 8.53° vs. 20.21° ± 13.21°), and dC12cobb (9.49° ± 5.16° vs. 1.07° ± 12.44°) between the two groups were significant (P < 0.05). Multiple logistic regression analyses revealed that dC12cobb > 5° was a significant independent risk factor for postoperative dysphagia, And preoperative C27cobb was a preventive factor of postoperative dysphagia.ConclusionsDysphagia after the C1-2 fusion was common. dC02cobb and dC12cobb were the significant independent risk factors for postoperative dysphagia. Preoperative c27cobb was a preventive factor of dysphagia.

Clinical and radiological comparison of the zero-profile anchored cage and traditional cage-plate fixation in single-level anterior cervical discectomy and fusion

BackgroundThe aim of this study was to compare the clinical outcomes and radiographic parameters of the zero-profile anchored cage and traditional cage-plate fixation in single-level anterior cervical discectomy and fusion (ACDF).MethodsBetween January 2016 and November 2018, a total of 68 patients with degenerative cervical spondylosis who underwent single-level ACDF were evaluated in this retrospective study. Thirty-five patients were treated with the zero-profile anchored cage (Zero-P group), and 33 patients were treated with the traditional cage-plate fixation (Cage group). The two groups were compared in reference to clinical outcomes and radiographic parameters.ResultsThe mean operation time in the Zero-P group was significantly shorter than that in the Cage group. The incidence of postoperative dysphagia in the Cage group was higher than that in the Zero-P group at 3 months and 12 months postoperatively. No bony spurs were found in the Zero-P group, whereas 5 patients in the Cage group developed bony spurs. There were no statistically significant differences between the two groups in the JOA scores, VAS scores, NDI scores, C2-7 Cobb angles, segmental Cobb angles, total interbody height or fusion rates at 3 months or 12 months postoperatively.ConclusionIn this study, both the zero-profile anchored cage and traditional cage-plate fixation were demonstrated to be effective and safe strategies. Given the lower incidence of dysphagia and degenerative changes, zero-profile anchored cage is a good option.

Is Anterior Trans‐Intervertebral Space Decompression Important in Treating Cervical Spondylosis with Severe Intervertebral Space Narrowing? A Retrospective Cohort Study

To evaluate the clinical efficacy and practicality of anterior trans-intervertebral space decompression and fusion (ATIDF) by comparing radiological and clinical outcomes between ATIDF and traditional anterior cervical corpectomy and fusion (ACCF) in cervical spondylosis patients with severe disc space narrowing. Seventy-one cervical spondylosis patients with severe disc space narrowing underwent anterior cervical spine surgery were included in this retrospective study. Thirty-seven patients underwent ATIDF and 34 patients underwent ACCF. The neck disability index (NDI), Japan Orthopaedic Association (JOA) score and the Hirabayashi improvement rate were used to evaluate patient neurological status. Cervical sagittal alignment (C2-C7 Cobb angle), surgical segment sagittal alignment (Cobb angle of surgical segment) and disc space height were also compared between the two groups. There were 39 males and 32 females; mean age was 63.72 ± 6.36 years (range, 39-81 years). Mean follow-up was 22.4 months (range, 6-45 months). All patients achieved an adequate neurological improvement. There were no significant differences in NDI, JOA scores and Hirabayashi improvement rate between the two groups. The change of C2-7 Cobb angle and surgical segment Cobb angle were both greater in the ATIDF group. The average intervertebral height ratio of the patients in the ATIDF group increased significantly after surgery (0.38 ± 0.17 before surgery to 1.13 ± 0.32 after surgery, P < 0.01). The overall complication rate was lower in the ATIDF group than the ACCF group (35.14% and 44.12%). At 6 months follow-up, three patients in the ACCF group presented with subsidence of the titanium mesh cage. ATIDF is an effective technique for treating cervical spondylosis with severe disc space narrowing; it can achieve adequate decompression and improve sagittal alignment while avoiding and reducing the implant-related complications inherent to traditional ACCF.

Correlation between C7-T1 Intervertebral Foramen Area and Sagittal Parameters in Patients with Cervical Spondylotic Myelopathy.

Cervical spondylotic myelopathy (CSM) is an incomplete spinal cord injury characterized with pain and stiffness in the neck and motor and sensory dysfunction. This study aims to determine whether C7-T1 intervertebral foramen area could be used as a parameter to evaluate the sagittal curvature of cervical spine. Patients with clinical manifestations of spinal cord compression were hospitalized in our hospital from September 2018 to August 2019. All patients were diagnosed with CSM by nuclear magnetic imaging and other imaging methods. C2-C7 Cobb angle and T1 slop (T1S) were measured on the sagittal, T2-weighted magnetic resonance image of cervical spine, and C7-T1 intervertebral foramen area were measured using oblique cervical spine X-rays. Patients were divided into two groups according to the value of C2-C7 Cobb angle, including lordosis group (C2-C7 Cobb angle >10°, n=45) and straight group (C2-7 Cobb angle ≤10°, n=55). The reliability of the data was evaluated by intraclass correlation coefficient (ICC), and the correlation of the imaging parameters was analyzed by Pearson correlation. A total of 100 patients diagnosed with CSM hospitalized in our department were included. The ICC of the cervical parameters was 0.73. C7-T1 intervertebral foramen area was 40.69 ± 11.44 and 39.95 ± 10.94 mm2 in lordosis and straight group, respectively. The results showed that C7-T1 intervertebral foramen area was positively correlated with both C2-C7 Cobb angle (r=0.23, p=0.02) and T1S (r=0.21, p=0.03). In lordosis group, there was a positive correlation between C7 and T1 intervertebral foramen area and C2-C7 Cobb angle (r=0.69, p < 0.01) and T1S (r=0.34, p=0.02). However, in straight group, C7-T1 intervertebral foramen area was not correlated with either C2-C7 Cobb angle or T1S. C7-T1 intervertebral foramen area measured by oblique X-ray could be an effective method to evaluate the sagittal balance of cervical vertebrae for CSM patients with cervical lordosis.

Global Spinal Realignment After Osteotomized Debridement in Active Lumbar Spinal Tuberculosis: Correlation with Patient-Reported Outcomes

Osteotomized debridement (OD) has been proved to be highly effective in treating active thoracolumbar tuberculosis (TB); however, no research has investigated how OD affects spinal alignment. The goal of this study was to explore the global alignment compensatory mechanism after lumbar OD, as well as the correlation between spinopelvic parameters and patient-reported outcomes (PROs). Sixty-two patients with active lumbar spinal TB who underwent OD surgery were included. Spinopelvic parameters (C2-7 Cobb angle [C2-7 CA], sagittal vertical axis [SVA], proximal thoracic kyphosis, thoracic kyphosis, lumbar lordosis [LL], sacral slope [SS], pelvic tilt [PT], pelvic incidence [PI], spinosacral angle, and PI minus LL [PI-LL]) and PROs (Oswestry Disability Index [ODI] and Visual Analog Scale [VAS] score) were reviewed. The correlation between spinopelvic realignment and improved PROs was evaluated. Compared with preoperative measurements, C2-7 CA, proximal thoracic kyphosis, thoracic kyphosis, LL, SS, and spinosacral angle significantly increased after OD, whereas SVA, PT, and PI-LL significantly decreased. ODI and VAS score significantly improved postoperatively. The improvement of VAS was observed to be correlated with variations of C2-7 CA, SVA, LL, and PI-LL. The improvement of ODI was found to be correlated with variations of SVA, LL, and PI-LL. The multiple stepwise regression analysis showed that LL was an independent predictor for ODI and VAS score. The whole spine and pelvis are involved in realignment after lumbar spinal OD, which is closely related to PROs. More attention should be drawn to restoring an appropriate LL in lumbar TB surgery.

Analysis of the Risk Factors for C5 Nerve Palsy After Cervical Posterior Open-Door Laminoplasty for Patients with Cervical Spondylotic Myelopathy—From the Perspective of Cervical Sagittal Parameters

This study was performed to explore the sagittal radiological parameters related to the occurrence of C5 nerve palsy after cervical posterior open-door laminoplasty for the patients with cervical spondylotic myelopathy. Sixty-two patients who underwent cervical posterior open-door laminoplasty were reviewed retrospectively from March 2017 to March 2022. The C2-7 Cobb angle, C2-7 sagittal vertex axis, thoracic inlet angle, neck tilt, T1 slope, and encroachment ratio of ossification were measured on X-rays. The enrolled patients were divided into C5 nerve palsy and control groups. Logistic regression was performed to analyze the potential risk factors for the occurrence of C5 nerve palsy. The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) were used to evaluate the significance of the results and the optimal diagnostic value. The results of logistic regression showed that only the T1 slope and encroachment ratio were variables that were responsible for C5 nerve palsy (P= 0.024; P= 0.04). The ROC curve analysis for the T1 slope showed that the cutoff value was 21.3° and the AUC was 0.796. The ROC curve analysis for the encroachment ratio revealed that the cutoff value was 0.21 and the AUC was 0.763. Both analyses demonstrated good diagnostic value for C5 nerve palsy. The preoperative T1 slope and encroachment ratio were variables that were risk factors for C5 nerve palsy in patients who underwent cervical posterior open-door laminoplasty.

Efficacy comparison of zero-profile intervertebral fusion and stand-alone interbody cage combined with cage-titanium plate construct in treatment of two-segment skip cervical spondylosis

Objective: To investigate the difference in clinical efficacy between zero-profile interbody fusion (ROI-C) and stand-alone interbody cage combined with cage-titanium plate construct for patient with two-segment skipped cervical spondylosis who received the anterior cervical discectomy and fusion (ACDF) surgical strategies. Methods: The clinical data of 62 patients with two-segment skipped cervical spondylosis who underwent surgical treatment in the First Affiliated Hospital of Zhengzhou University from June 2017 to June 2020 were retrospectively analyzed, included 38 males and 24 females, aged (53.3±8.5) years. Thirty-three cases were treated with ROI-C (ROI-C group), and 29 cases with stand-alone interbody cage combined with cage-titanium plate construct (cage+titanium plate group). The following parameters, including operation time, intraoperative blood loss, dysphagia Bazaz grade, Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) of pain, neck disability index (NDI), average intervertebral height of operated segments, C2-7 Cobb angle, and related complications, were compared between the two groups. Results: The patients were followed up for (28±5) months (16-34 months). The operation time of ROI-C group was (127.6±34.2) min, which was shorter than that in cage+titanium plate group [(157.1±43.9) min, P=0.004]. The scores of JOA and VAS in both ROI-C group and cage+titanium plate group were significantly improved 3 months after operation when compared with those before operation, and there was no significant difference between the two groups (all P>0.05). The average intervertebral space height of fusion segment in ROI-C group was (6.02±1.03) mm before operation, it was improved to (8.38±1.47) mm at 3 months after operation, (8.16±1.40) mm at 12 months after operation, and it was (6.24±1.05) mm, (8.58±1.18) mm and (7.87±0.73) mm in cage+titanium plate group, respectively, and there was no significant difference between the two groups at each time point (all P>0.05). The Cobb angle of cervical vertebrae in ROI-C group was 10.5°±6.8° before operation, improved to 19.2°±9.0° at 3 months after operation, 18.2°±5.8° at 12 months after operation, and it was 10.9°±4.6°, 18.5°±7.8°, 17.1°±5.2° in cage+titanium plate group, respectively, and there was no significant difference between the two groups at each time point (all P>0.05). The incidence of postoperative dysphagia was 9.1%(3/33) in the ROI-C group and 37.9%(11/29) in the cage+titanium plate group, and the difference was statistically significant (P=0.007). Conclusions: Both ROI-C and stand-alone interbody cage combined with cage-titanium plate construct can achieve good results for two-segment skipped cervical spondylosis. However, ROI-C is more advantageous in shortening the operation time and reducing early postoperative dysphagia.

Mechanisms of compensatory for cervical lordosis changes after laminectomy with fusion

BackgroundThe compensatory mechanisms for cervical lordosis change after laminectomy with fusion was not clear. The objective of this study was to evaluate the compensatory behaviors for cervical lordosis change after laminectomy with fusion.MethodsThis was a retrospective radiological analysis of 43 patients with cervical spondylotic myelopathy who underwent laminectomy with fusion (LCF). The following cervical parameters were measured: C2-7 Cobb angle (C2-7), occiput-C2 angle (O-C2), the cervical sagittal vertical axis (cSVA), and T1 slope (T1S). The difference was calculated for all angle parameters between the two time points using the following formula: the amount of change (Δ) = (value at the follow-up)—(preoperative value). Non-parametric tests and the t-test were used to compare the difference. The Pearson correlation test was performed, and stepwise multiple regression analysis was performed to determine the best correlation between ∆cSVA and ∆T1S.ResultsThe mean age of 43 patients was 65.51 ± 9.80 years. All patients were classified into two subgroups based on ΔcSVA: Group M (maintained) and, Group I (increased). The preoperative O-C2, C2-7, T1S, and cSVA were similar between Group M and group I (p = 0.950, p = 0.731, p = 0.372, and p = 0.152, respectively). Postoperative O-C2 and postoperative cSVA were significantly different (p = 0.036 and p = 0.004, respectively). ∆O-C2, ∆T1S and ∆cSVA were significantly different between the two groups (p = 0.006, p = 0.000, and p = 0.000, respectively). ΔcSVA had significant correlations with ΔO-C2 neutral angle (r = 0.377) and ΔT1S (r = 0.582). A linear regression equation was established: ΔcSVA = 0.602 + 0.103 * ΔT1S (R = 0.582, R2 = 0.339).ConclusionsThe decrease of TIS should be the first and foremost compensation for the loss of lordosis in C2-7 segments after LCF. When the change of T1S alone can not prevent the deterioration of cervical sagittal balance, further increases in the O-C2 segment occur.

Effect of cervical alignment change after anterior cervical fusion on radiological adjacent segment pathology

Adjacent segment pathology (ASP) is one of the primary complications affecting the long-term efficacy of anterior cervical fusion (ACF). At present, the cause and mechanism of adjacent segmental lesions are still controversial. We performed a retrospective analysis on 88 patients with cervical spondylotic myelopathy (CSM) who had been followed up for at least 1 year after ACF. The patients were divided into radiological adjacent segment pathology (RASP) and non-RASP groups according to the presence of postoperative RASP. On the lateral radiographs of the cervical spine of all patients taken before and after surgery at the short-term and final follow-ups, the following parameters were measured: C2-7 Cobb angle of the cervical vertebrae; Cobb angle of the operated segments; and the anterior and posterior height of the fused segments [i.e., the anterior fusion segment height (AFH) and the posterior fusion segment height (PFH)]. The intra- and inter-group differences of the patients before and after surgery were calculated, as well as correlation of ACF with the occurrence of RASP. There were 42 cases in the RASP group and 46 cases in the non-RASP group. In the RASP group, the C2-7 Cobb angle was significantly reduced in the short term after surgery (20.42±9.92° vs. 13.81±8.52°, P<0.01), while in non-RASP group the C2-7 Cobb angle was significantly increased in the short term after surgery (12.65±11.91° vs. 15.35±10.05°, P<0.05). The heights of both the anterior and posterior fused segments in the 2 groups were significantly higher after surgery, and they were significantly lower at the final follow-up than at the short-term follow-up. Post-operative AFH change was significantly correlated with C2-7 Cobb angle (r=0.274, P=0.010) and fused segment Cobb angle change (r=0.333, P=0.002). However, Cox regression analysis showed that only the postoperative C2-7 Cobb angle change was associated with RASP, with a hazard ratio of 0.336. Decreased cervical lordosis after ACF may be related to postoperative RASP. Maintaining good cervical curvature after surgery may reduce the incidence of RASP after ACF.

Investigation of Titanium Mesh and Nano-Hydroxyapatite/Polyamide 66 Bone Graft in Cervical Reconstruction of Spondylosis After Sub-Total Vertebral Body Resection

The nano-hydroxyapatite/polyamide 66 (n-HA/PA66) bionic bone column, as a high-performance tissue repair and replacement material, introduced as a high osteo-induction ability agent. Nanomaterial has significantly taken a place in orthopedic surgery, however, the efficacy of using n-HA/PA66 is yet to be established. In this regard, this study evaluated various sagittal parameters (such as imaging measurement) and clinical efficacy in postoperative patients, whom underwent cervical reconstruction surgery due to cervical spondylosis myelopathy (CSM). In this study, total 62 CSM cases were enrolled between October 2016 to March 2020, and were hospitalized for cervical reconstruction surgery. 31 cases were grafted with titanium mesh and 31 cases were grafted with n-HA/P66. The sagittal parameters such as cervical spine lateral radiographs (C0-2Coob, C2-7Coob, T1S, CSVA, and TIA) were taken before operation, after operation (within 1 week), 3, 6, and 9 months after operation. In order to evaluate the clinical efficacy, we used JOA scores before, after, 3 months, 6 months and 9 months after operation. Results showed that JOA scores after the re-examination in the two groups (titanium and n-HA/P66) were significantly higher than before the operation, suggesting a well postoperative functional recovery after surgery in both groups; however, there was no significant difference in JOA score and JOA improvement index between the two groups. In regard of angles measurement (C0-2Cobb, C2-7Cobb, T1S, CSVA, and TIA), we observed no significant difference between these two groups before and after the operation. In addition, we showed that C0-2Cobb and C2-7Cobb angle had a significant positive correlation; and C0-2Cobb angle is positively correlated with T1S, and negatively correlated with CSVA. Both titanium mesh and n-HA/PA66 can be well improved and maintained within 9 months after surgery with clinical efficacy, however, using n-HA/PA66 might have more benefits.