Cervical Kyphosis Research Articles

Front-Back Cervical Deformity Correction by Anterior Cervical Discectomy and Fusion With Posterior Instrumentation: 2-Dimensional Operative Video.

Front-back procedures for cervical deformity permit the correction of cervical kyphosis in the setting of unfused facets. Here, we highlight the operative treatment of a 65-yr-old female entailing a 4-level anterior cervical discectomy and fusion (ACDF) at C3-C4, C4-C5, C5-C6, and C6-C7 with hyperlordotic interbody implants, supplemented by a posterior C2-T2 instrumented fusion. The patient initially presented with symptoms of treatment-refractory neck pain while neurologically intact on examination. Her imaging demonstrated significant cervical kyphosis measuring 46° as the Cobb angle between C2 and C7 without neural compression. The patient consented to the procedure and publication of their image. After 2 d of traction, the operation proceeded with the patient initially in a supine position with dissection medial to the sternocleidomastoid muscle down to the vertebral bodies. Discectomies were performed at each level followed by installation of the interbody implants. After closure of this access wound, the patient was turned to a prone position for the posterior element of the operation. The posterior bony elements were exposed and a C2-T2 instrumented fusion performed. Postoperative imaging demonstrated improvement of her sagittal cervical curvature and the patient described improvement in her neck pain.

102. How the back affects the neck: preoperative sagittal vertical axis is correlated with cervical myelopathy scores

102. How the back affects the neck: preoperative sagittal vertical axis is correlated with cervical myelopathy scores

30. Outcomes analysis of staged vs same day surgery patients undergoing identical cervical deformity corrective surgery

BACKGROUND CONTEXT Surgical intervention aimed at addressing adult cervical deformity (ACD) is an invasive and complex procedure that surgeons often elect to perform on different days. Despite patients undergoing staged procedures being older, with more comorbidities, staged patients had superior short- and long-term outcomes while undergoing less osteotomies, possibly leading to the overall decrease in complications. PURPOSE To determine differences in outcomes between staged vs same-day procedures. STUDY DESIGN/SETTING Retrospective cohort study of single-center database. PATIENT SAMPLE A total of 65 CD patients. OUTCOME MEASURES Complications; radiographic parameters; HRQL metrics (Neck Disability Index [NDI], EQ5D, mJOA, Numerical Rating Score [NRS] neck and back pain). METHODS Inclusion criteria: operative CD patients (cervical kyphosis>10°, with cSVA>4cm or CBVA>25°) and >18yrs undergoing either staged or same-day procedures. Significant differences in surgical, radiographic and clinical factors and outcomes were determined. RESULTS A total of 65 CD patients met inclusion criteria (58.3 years, 46% Female, 28.3 kg/m2). Overall, 32 (48%) of these patients underwent staged procedures, while 33 (52%) underwent a same-day combined approach. Staged patients were older (61 vs 56, p=.03) and had a higher CCI (1 vs .63, p=.13). Patients that had a staged procedure experienced fewer overall complications (22% vs 43%, p=.002) and less neurological complications (p<0.05). Staged patients had an overall lower usage of osteotomies (25% vs 53%, p=.02). Staged patients had a lower 6W NDI score (47 vs 56, p=.16), lower 3M NSR Neck (5.5 vs 6.6) and Back pain score (5.2 vs 5.9), lower 6M NSR Neck (3.5 vs 5.2), back pain score (3.4 vs 5.6) and NDI score (30 vs 40). At 2-years follow-up, staged patients had a lower NSR neck (3.6 vs 6.2), back pain score (4.4 vs 7.4), NDI score (28 vs 43, all p<0.05) and higher mJOA/SWAL scores. CONCLUSIONS Staged procedures have become more prevalent as surgeons aim to decrease perioperative adverse events and improve patient outcomes. Despite patients undergoing staged procedures being older, with more comorbidities, staged patients had superior short- and long-term outcomes while undergoing less osteotomies, possibly leading to the overall decrease in complications. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Surgical intervention aimed at addressing adult cervical deformity (ACD) is an invasive and complex procedure that surgeons often elect to perform on different days. Despite patients undergoing staged procedures being older, with more comorbidities, staged patients had superior short- and long-term outcomes while undergoing less osteotomies, possibly leading to the overall decrease in complications. To determine differences in outcomes between staged vs same-day procedures. Retrospective cohort study of single-center database. A total of 65 CD patients. Complications; radiographic parameters; HRQL metrics (Neck Disability Index [NDI], EQ5D, mJOA, Numerical Rating Score [NRS] neck and back pain). Inclusion criteria: operative CD patients (cervical kyphosis>10°, with cSVA>4cm or CBVA>25°) and >18yrs undergoing either staged or same-day procedures. Significant differences in surgical, radiographic and clinical factors and outcomes were determined. A total of 65 CD patients met inclusion criteria (58.3 years, 46% Female, 28.3 kg/m2). Overall, 32 (48%) of these patients underwent staged procedures, while 33 (52%) underwent a same-day combined approach. Staged patients were older (61 vs 56, p=.03) and had a higher CCI (1 vs .63, p=.13). Patients that had a staged procedure experienced fewer overall complications (22% vs 43%, p=.002) and less neurological complications (p<0.05). Staged patients had an overall lower usage of osteotomies (25% vs 53%, p=.02). Staged patients had a lower 6W NDI score (47 vs 56, p=.16), lower 3M NSR Neck (5.5 vs 6.6) and Back pain score (5.2 vs 5.9), lower 6M NSR Neck (3.5 vs 5.2), back pain score (3.4 vs 5.6) and NDI score (30 vs 40). At 2-years follow-up, staged patients had a lower NSR neck (3.6 vs 6.2), back pain score (4.4 vs 7.4), NDI score (28 vs 43, all p<0.05) and higher mJOA/SWAL scores. Staged procedures have become more prevalent as surgeons aim to decrease perioperative adverse events and improve patient outcomes. Despite patients undergoing staged procedures being older, with more comorbidities, staged patients had superior short- and long-term outcomes while undergoing less osteotomies, possibly leading to the overall decrease in complications.

237. The effect of sagittal alignment on adult cervical deformity patient outcomes, reoperation rates and development of distal junctional kyphosis

<h3>BACKGROUND CONTEXT</h3> Global spinal malalignment plays a vital role in cervical spinal deformity corrective surgery outcomes; however, the literature is scarce on the effects that the individual sagittal parameters have on outcomes. <h3>PURPOSE</h3> To investigate the impact of sagittal malalignment on cervical deformity patient outcomes. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study of single-center database. <h3>PATIENT SAMPLE</h3> This study included 123 CD patients. <h3>OUTCOME MEASURES</h3> Complications; radiographic parameters; HRQL metrics (NDI, EQ5D, mJOA, NRS Neck) <h3>METHODS</h3> Inclusion criteria: operative CD patients (cervical kyphosis >10°, with cSVA >4cm or CBVA >25°) and >18yrs with up to 2Y radiographic and HRQL follow-up. Significant differences in surgical, radiographic, and clinical factors and outcomes were determined. Deformity in PT, SVA, and PILL was defined using the SRS-Schwab criteria. "Unmatched" refers to patients who were under corrected or over corrected according to the Schwab age-adjusted parameters (Lafage et al.). <h3>RESULTS</h3> A total of 123 CD patients met inclusion criteria (58.3 yrs, 46% Female, 28.3 kg/m2). Overall, 27 (24%) of these patients developed DJK. At baseline, patients presented with the following radiographic profile: PT (18.3), PILL (-.65), SVA C7-S1 (-6.54), cSVA C2-C7 (23.5), and TS-CL (25.2). Patients with DJK had a higher L1-S1 (34 vs 9.2) and T12-S1 (57 vs 35, both p<0.05) and trended towards a higher cSVA (-11.7 vs -3.7), C2-T3 (57.6 vs 37.4), and C2-S1 (17 vs 5.9, p>0.05). Patients with a deformity in PT at baseline developed more DJK by 2 years (26% vs 11%), had more DJF (7% vs 2%) and a higher NDI and NSR back pain. Patients with mismatch at baseline had higher rates of DJK (30% vs 22%), and patients with SVA deformity at baseline had a lower mJOA, SWAL Food selection, SWAL Communication, and a higher EQ5D. Patients with a mismatched alignment in Roussouly preoperatively had higher rates of DJK at 3M (18% vs 12%), 6M (26% vs 16%), 1Y (24% vs 14%), and 2Y (26% vs 13%, all p<0.05). Patients who were unmatched in SVA by 2Y had higher rates of DJK development at 2Y (25% vs 6%), and those unmatched in PILL by 2Y had higher rates of 2-year DJK (31% vs 19%) and higher 2-year NDI (38 vs 31). Patients who had a mismatch in Roussouly postoperatively had higher rates of DJK by 2 years (33% vs 23%, allp<0.05). <h3>CONCLUSIONS</h3> Global spinal malalignments play an important role in the outcomes of cervical spinal deformity corrective surgery. The presence of abnormal global sagittal malignment at baseline is associated with higher rates of DJK development and worse clinical outcomes, while patients who maintained poor sagittal alignment up to 2Y were associated with significantly greater development of DJK and inferior neck disability index scores. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

194. The effect of undercorrection on distal junctional kyphosis in adult cervical deformity patients

<h3>BACKGROUND CONTEXT</h3> Distal junctional kyphosis (DJK) development after cervical deformity (CD) corrective surgery is a growing concern for surgeons and patients. Although proper realignment is known to help mitigate the development of DJK, there has yet to be a study that critically analyzes under correction in certain parameters and the effects on development of DJK. <h3>PURPOSE</h3> To determine the effects of under correction in the development of DJK. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study of single-center database. <h3>PATIENT SAMPLE</h3> This study included 195 CD patients. <h3>OUTCOME MEASURES</h3> Complications; radiographic parameters; HRQL metrics (NDI, EQ5D, mJOA, NRS Neck). <h3>METHODS</h3> Inclusion criteria: operative CD patients (cervical kyphosis >10°, with cSVA>4cm or CBVA>25°) and >18yrs with up to 2-year radiographic and HRQL follow-up. Significant differences in surgical, radiographic, and clinical factors and outcomes were determined. Under correction was defined by a deformity in TS-CL or cSVA Ames Modifier. Moderate Ames cervical lordosis deformity (CL) was TS-CL >15 and high >20, high cSVA deformity was >8cm. <h3>RESULTS</h3> A total of 195 CD patients met inclusion criteria (58.3yrs, 46% Female, 28.3 kg/m2). Overall, 40 (21%) of these patients developed DJK. At baseline patients presented with the following radiographic profile: PT (18.3), PI-LL (-.65), SVA C7-S1 (-6.54), cSVA C2-C7 (9.7), and TS-CL (24). Patients undercorrected in TS-CL developed DJK at a greater rate (28% vs 15%, p=.02), and patients undercorrected in cSVA developed more DJK (65% vs 16%) and underwent more reoperations (42% vs 17%, both p<0.05). Controlling for baseline deformity, frailty and age, patients who maintained a high cSVA deformity had a 3.2 times higher likelihood of developing DJK (3.2[1.6-6.8], p=.002). Patients with a postoperative moderate CL deformity had a 1.8 times higher likelihood of DJK (1.8[.9-3.8], p=.105), and with a high CL deformity, a 2.8 times higher likelihood (2.8[1.1-7.2], p=.03). Controlling for the same factors, patients who remained undercorrected in both cSVA and TS-CL had a 6 times times higher likelihood of developing DJK (6[1.9-17], p=.002). Using CIT to find a threshold cutoff, the risk of DJF was considerably increased for patients with a TS-CL greater than 13.5, (2.4[1.14-5], p=.026), and a cSVA deformity greater than 6cm (3.2[1.5-6.6], p=.026). Patients who were adequately corrected in cSVA and undercorrected in TS-CL demonstrated no significant increased vulnerability to DJK, (p>0.05). <h3>CONCLUSIONS</h3> The TS-CL and cSVA components of Ames criteria show a strong correlation with development of distal junctional kyphosis (DJK). Thresholds for DJK development suggests even patients who fall into a mild deformity as per the Ames criteria are still at an increased risk, and more strict alignment goals may further prevent mechanical failure. cSVA was found to be the dominant radiographic parameter impacting DJK development. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P104. Identifying C2 slope and T1 slope thresholds for optimal functional and clinical outcomes in cervical deformity correction

<h3>BACKGROUND CONTEXT</h3> Surgical correction of cervical deformity (CD) has been associated with superior alignment and functional outcomes. It has not yet been determined whether baseline and postoperative T1 slope and C2 slope correlate with health-related quality of life (HRQL) metrics and radiographic complication. <h3>PURPOSE</h3> To determine the impact of T1S and C2S deformity severity on HRQL metrics and DJK development in operative cervical deformity patients. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> A total of 119 CD patients. <h3>OUTCOME MEASURES</h3> Radiographic parameters; HRQLs. <h3>METHODS</h3> Included: Operative CD patients with UIV above C7 and with pre-(BL) and up to 2-year (2Y) postop radiographic/HRQL data. Cervical deformity was defined as meeting at least one of the following radiographic parameters: C2-C7 lordosis < -15°, TS-CL >35°, segmental cervical kyphosis >15° across any 3 vertebra between C2-T1, C2-C7 SVA >4cm, McGregor's slope >20°, or CBVA > 25°. Spearman's rank-order correlation and linear regression analysis assessed the impact of baseline T1 slope (T1S) and C2 slope (C2S) on baseline HRQL metrics (NDI, mJOA, EQ5D, NRS Neck, NRS Back), and the impact of postoperative T1S and C2S on follow-up HRQLs. Logistic regression and conditional inference tree (CIT) machine learning were used to determine baseline radiographic thresholds for improving in ≥2 HRQL metrics from BL to 2Y, and 2Y radiographic thresholds for developing DJK or DJF by 2Y postop. <h3>RESULTS</h3> A total of 119 CD patients met inclusion criteria (61.2±10.5years, 63%F, BMI 29.0±7.5kg/m2, CCI: 1.00±1.31) and underwent surgery (levels fused 7.5±3.7, EBL 990mL, op time 547min). By approach, 19.3% anterior-only, 44.5% posterior-only, and 36.1% combined. Mean BL radiographic parameters: PT 19.6°, PI-LL 1.4°, SVA 1.9mm, T2-T12 kyphosis -46.8°, C2-C7 lordosis -9.0°, T1S 29.0°, TS-CL 38.2°, C2S 37.7°, cSVA 44.0mm, and C2-T3 -18.0°. Mean BL HRQLs were as follows: NRS back 5.0, NRS neck 6.7, NDI 47.9, mJOA 13.5, and EQ5D 0.74. Spearman correlation and linear regression identified no association between baseline T1S or C2S and HRQL metrics, or between 2Y postop T1S and HRQLs (all p>0.05). Correlation and linear regression found significant associations of higher C2S with higher NDI (p=0.042), lower mJOA (p=0.011), and lower EQ5D (p=0.009), all indicating higher degree of disability at 2Y postop. Logistic regression with CIT identified thresholds for improving in 2 or more HRQL metrics by 2Y postop: baseline T1S < 32.8° (OR: 2.47) and C2S <46.7° (OR: 2.40); both p<0.05. Regression and CIT also identified postoperative radiographic thresholds for developing DJK or DJF by 2Y: T1S >45.3° (OR: 16.0) and C2S >32.5° (OR: 6.07); both p<0.05. <h3>CONCLUSIONS</h3> Baseline deformity severity in terms of T1 slope and C2 slope can be predictive of postoperative functional outcomes in cervical deformity patients, while postoperative deformity in T1S and C2S can be predictive of DJK and DJF occurrence. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P105. When does the construct need to extend to the thoracic spine in patients undergoing correction for cervical deformity?

<h3>BACKGROUND CONTEXT</h3> Thoracolumbar malalignment is often seen in patients presenting with cervical deformities. For operative cervical deformity (CD) patients, it is unknown when the thoracic spine should be included in the construct. <h3>PURPOSE</h3> To investigate the CD patients in whom fusion to the thoracic spine was warranted. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> A total of 72 CD patients. <h3>OUTCOME MEASURES</h3> Radiographic parameters; complications, distal junctional kyphosis [DJK], reoperation; Health-Related Quality-of-Life [HRQLs]: NDI, NRS-neck, mJOA. <h3>METHODS</h3> Included: operative CD patients (C2-C7 lordosis < -15°, TS-CL >35°, segmental cervical kyphosis >15° across any 3 vertebra between C2-T1, C2-C7 SVA >4cm, McGregor's slope >20°, or CBVA > 25°) with baseline (BL) and up to 2-year (2Y) data. Patients with UIV at or above C4 and LIV extending beyond C7 into the thoracic spine were isolated (CT fusions). CT fusion patients were further stratified to upper and lower thoracic LIVs: T1-T4 [Short Fusion], beyond T4 [Long Fusion]. CT fusion patients were identified as having an optimal outcome at 2-year postop if they 1) did not have DJF and 2) had Virk et al. good clinical outcome [≥2 of the following: NDI <20 or meeting MCID, mild myelopathy (mJOA ≥14), NRS-Neck ≤5 or improved by ≥2 points from baseline]. Univariate analysis compared patients with long fusion and optimal outcome (L/Success) vs patients with short fusion and treatment failure (S/Fail). Multivariate analysis and ROC curve assessed demographic, surgical, and radiographic predictors of S/ Fail and L/S Success status. Conditional inference tree (CIT) determined cut-off values for the continuous predictors. <h3>RESULTS</h3> Seventy-two cervical deformity patients with CT fusion included (60.3±9.0years, 60% F, 29.4±7.6 kg/m2, levels fused: 7.8±3.2). By approach, 61% posterior-only and 39% combined. Fifty-nine patients (82%) had CT fusions with LIV of T4 or above, while 13 patients (18%) had fusions extending below T4. Thirty-two patients (44.4%) met the optimal outcome criteria, with no difference by fusion length (p=0.171). Eight patients qualified as long fusions with treatment success, while 35 patients were classified as short fusions with treatment failure. Regression analysis identified the predictors of treatment success in patients with fusion construct extending beyond T4: baseline sacral slope ≤33.5° (OR: 15.0), not undergoing high grade (PSO or VCR) osteotomy (OR: 15.0) and being Ames descriptor type C (OR: 13.5); all p<0.05). ROC curve accounting for these factors resulted in an AUC of 82.0%. Regression analysis identified predictors of treatment failure in patients with short fusion construct: levels fused >6 (OR: 4.3), Ames descriptor type CT (OR: 11.5), Ames cSVA modifier grade 1 or 2 at BL (OR: 4.56), and Flatneck Lafage morphotype (OR: 4.5); all p<0.05. Multivariate regression and ROC curve accounting for these factors resulted in an AUC of 84.3%. <h3>CONCLUSIONS</h3> Treatment success in patients with fusion constructs extending into the thoracic spine vs treatment failure in patients with short fusions may be reliably predicted by the location of the deformity apex, measures of surgical invasiveness, and preoperative deformity severity. Specifically, treatment success in longer fusions is related to deformity apex in the cervical spine and having deformity where adequate correction does not necessitate high grade osteotomy. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Transiency of postoperative cervical kyphosis seen after surgical correction of sagittal malalignment in adult spinal deformity patients.

ObjectiveIn this study, we evaluated factors affecting changes in cervical lordosis after deformity correction and during follow-up period in adult spinal deformity (ASD) patients with severe sagittal imbalance.MethodsSeventy-nine patients, with an average age of 71.6 years, who underwent long-segment fixation from T10 to S1 with sacropelvic fixation were included. We performed a comparative analysis of the radiographic parameters after surgery (Post) and at the last follow-up (Last). We calculated the Pearson’s correlation coefficient and performed multilinear regression analysis to predict independent parameters for Post and Last cervical lordosis (CL), T1 slope (T1S), and thoracic kyphosis (TK).ResultsHyperlordotic changes of -23.3° in CL before surgery was reduced to -7° after surgery, and Last CL had increased to -15.3°. T1S was reduced from 27° before surgery to 14.4° after surgery and had increased to 18.8° at the last follow-up. Through multilinear regression analysis, we found that Post CL and T1S were more significantly affected by the amount of LL correction (p = .045 and .049). The effect of Last T1S was significantly associated with the Last CL; the effect of Last TK, with the Last T1S; and the effect of Post PI-LL, with the Last TK (p < .05).ConclusionThe postoperative kyphotic change in CL in ASD patients with preoperative cervical hyperlordosis is not permanent and is affected by drastic LL correction and SVA restoration. To achieve spinopelvic harmony proportional to the difference in LL relative to PI, TK becomes modified over time to increase T1S and CL, in an effort to achieve optimal spine curvature.

Is Complete Correction of Cervical Sagittal Malalignment Necessary During 4-Level Anterior Cervical Discectomy and Fusion Surgery in Patients With Kyphosis?

Retrospective analysis. We investigated whether complete correction of cervical sagittal malalignment is necessary during 4-level anterior cervical discectomy and fusion (ACDF) in patients with kyphosis. This retrospective study included 84 patients who underwent 4-level ACDF surgery at a university hospital between January 2010 and December 2015. Based on the degree of cervical lordosis correction, patients were categorized into the following groups: mild (0-10°), moderate (10-20°), and complete correction (>20°). The clinical outcomes, radiological parameters, and functional outcomes were analyzed. We observed no significant intergroup differences in the baseline characteristics. The cervical sagittal vertical axis (CSVA) correction loss at the final follow-up was lesser in the mild- and moderate- than in the complete-correction group. The spinocranial angle (SCA) and T1 slope (T1 S) were significantly higher in the moderate- and complete-correction groups than in the mild-correction group, 3 days postoperatively. The cervical proximal junctional kyphosis (CPJK), adjacent segment degeneration (ASD), and ASD following CPJK rates were higher in the complete-correction group. We observed no significant intergroup differences in postoperative complications; however, 5 patients showed internal fixation failure in the complete-correction group; 4 of these patients required reoperation. No significant intergroup difference was observed in the Japanese Orthopedic Association and neck disability index scores at any time point. A mild-to-moderate correction of cervical lordosis is superior to complete correction in patients with kyphosis who undergo 4-level ACDF because this approach is associated with lesser axial stress and CSVA correction loss.

Comparable study of alternative-level and all-level Arch mini-plate fixation for unilateral open-door laminoplasty

Objectives: To compare the clinical effect of alternative-level and all-level Arch mini-plate fixation in patients undergoing unilateral open-door laminoplasty. Methods: Clinical data of 134 patients administrated in the Peking University International Hospital for multistage cervical spondylotic myelopathy from March 2015 to March 2019 were reviewed retrospectively. There were 63 males and 71 females with an average age of (62±8) years and a mean disease course of (18±7) months (3-37 months). All the patients underwent posterior cervical unilateral open-door laminoplasty with Arch titanium plate fixation. All the patients were divided into two groups according to the different amount of titanium plates used during operation as follow: group A, Arch plates were fixed at the door sides of C3, C5 and C7 (n=68) and group B, Arch plates were fixed at the door sides of C3, C4, C5, C6 and C7 (n=66). Operation time, intraoperative blood loss, postoperative hospitalization days and the cost of consumables, the Japanese orthopaedic association (JOA) score, cervical dysfunction index (NDI), the rates of improved JOA score, cervical curvature index, C2-7 Cobb angle, cervical range of motion, sagittal diameter of vertebral canal, opening angle of laminar, hinges bone healing and surgery related complications (axial symptoms, C5 nerve root palsy, screw loosening, laminar re-closing, cervical kyphosis, etc.) were recorded and compared between the two groups. Results: There was no complications during the operation, and the mean follow-up was (20±8) months (14-48 months). There was no statistically significant difference between the two groups in terms of gender, age, course of disease and compression segments (all P>0.05). There was no statistically significant differences between the two groups in operation time, intraoperative blood loss and postoperative hospital stay too (all P>0.05). The cost of consumables in group A was (34 970±1 325) yuan, and it was (57 450±2 161) yuan in group B, the difference between the two groups was statistically significant (P<0.01). The JOA and NDI score were significantly improved 3 months and 1 year after operation in both groups (both P<0.05). The sagittal diameter of each segment of the spinal canal at C3, C4, C5, C6 and C7 were all significantly increased in both groups 3 months and 1 year after surgery (all P<0.05). The C2-7 Cobb angle and cervical curvature index were all significantly reduced in both groups 3 months and 1 year after surgery (all P<0.05). The cervical range of motion in both groups was significantly reduced 3 months and 1 year after surgery compared with that before surgery (both P<0.05). The range of motion of the cervical spine in group A was significantly higher than that in group B (P<0.05). The opening angles of C4 and C6 segment lamina in group A 3 months and 1 year after operation were significantly lower than those in group B (all P<0.05). At 3 months after the operation, the hinges healing rate of C4 and C6 in group B was significantly better than that of group A (both P<0.05). At 1 year after the operation, there was no difference in the hinges healing rate of C4 and C6 in the two groups (both P>0.05). There was no statistically significant difference in postoperative complications between the two groups (P>0.05). Conclusions: The safety and early clinical efficacy of alternative-level and all-level Arch titanium plate fixation in posterior cervical unilateral open-door laminoplasty are comparable, alternative-level fixation can effectively reduce the cost of hospitalization. The open Angle loss and lower early hinges healing rate of the non-fixed segment in the alternative-level fixed group does not lead to laminar re-closing in early period of post operation.

Cervical kyphosis in patients with thoracic idiopathic scoliosis.

Cervical kyphosis in patients with thoracic idiopathic scoliosis.

Analysis of sagittal curvature and its influencing factors in adolescent idiopathic scoliosis.

This study aimed to explore the characteristics of changes in the sagittal arrangement of the spine between adolescent patients with idiopathic scoliosis (AIS) and normal adolescents, the risk factors for AIS and the factors affecting the progress of AIS.X-ray images of the full length of the spine in standing position were taken in AIS patients and normal adolescents. Radiographic measurements made at intermediate follow-up included the following:C1 and C2 cervical lordosis and C2 - C7 curvature of cervical lordosis, C2-C7sagittal horizontal distance (C2-C7SagittalVerticalAxis, C2-C7SVA), TS-CL, after thoracic lobe (Thoracic Kyphosis, TK), thoracic lumbar segment Angle (thoracolumbar kyphosis, [TLK]), lumbar lordosis Angle (Lumbar Lordosis, LL), sacral slope Angle (Sacrum Slope, SS), pelvic tilt Angle (Pelvic Tilt, PT), pelvic incidence (PI), L5 Incidence (Lumbar5 Slope (L5S), L5 incidence (Lumbar5 Incidence (L5I), sagittal horizontal distance (CSVA), lower depression Angle of the 2nd cervical spine. The difference of sagittal plane parameters between AIS group and normal adolescent group was compared. To evaluate the progress of AIS, correlation analysis was conducted between diagonal 2 and other parameters. The main risk factors of AIS were determined by binary Logistic analysis.The CSVA of AIS patients was higher than that of healthy adolescents (AIS: 27.64 ± 19.56) mm. Healthy adolescents: (17.74 ± 12.8) mm), L5S (AIS: 19.93°= 7.07° and healthy adolescents: 15.38°= 7.78°, P = .024 < .05), C2 downward sag Angle (AIS: 15.12°= 2.7°;Healthy adolescents: 12.97°= 4.56°); AIS patients had lower TS-CL (AIS: 22.48 ± 6.09 and healthy adolescents: 28.26°= 10.32°), PT (AIS: 10.42°= 4.53° and healthy adolescents: 15.80°=7.68°), (AIS: 41.87°=9.72° and healthy adolescents: 48.75°= 8.22°). The main risk factor for idiopathic scoliosis in adolescents was L5 (OR = 1.239, 95%CI = 1.049–1.463, P = .012 < .05).L5S is a major risk factor for idiopathic scoliosis in adolescents. The larger PI is, the higher the risk of scoliosis progression is. In AIS patients, lumbar lordosis is increased, cervical lordosis is reduced, and even cervical kyphosis occurs.

Cervical sagittal alignment in Lenke 1 adolescent idiopathic scoliosis and assessment of its alteration with surgery: a retrospective, multi-centric study.

To document baseline cervical sagittal characteristics in Lenke 1 adolescent idiopathic scoliosis (AIS) patients and assess the alteration in these parameters with surgery. Pre-operative and 2-year postoperative radiographs of 82 Lenke 1 AIS patients recruited from five hospitals were analysed. Selected radiographic parameters capturing regional and global sagittal alignment were measured. Comparison was made between groups based on baseline thoracic kyphosis (TK: TK < 20°, TK ≥ 20°). Pre-operative and postoperative values were compared-the change in each radiographic parameter was correlated with the degree of sagittal and coronal correction. At baseline, TK was 29.8° ± 16°, cervical lordosis (CL) was -1° ± 14°, lumbar lordosis (LL) was -57.1° ± 21°, C2-C7 sagittal vertical axis (SVA) was 16 ± 14mm and C7-S1 SVA was -15 ± 28mm; 44% of patients had cervical kyphosis. Patients with thoracic hypokyphosis had a significantly lower LL and more kyphotic cervical spine compared to those with thoracic normohyperkyphosis. The effect of surgery on TK depended on pre-operative thoracic sagittal alignment-TK increased in patients with thoracic hypokyphosis, but decreased in patients with thoracic normohyperkyphosis. Neither CL nor C2-C7 SVA changed significantly with surgery; 46% of patients still had cervical kyphosis postoperatively. There is a high incidence of cervical kyphosis at baseline in AIS patients-more so in those with pre-operative thoracic hypokyphosis. Unlike TK, CL is not significantly altered with surgery-improvement in CL correlates weakly with sagittal correction of the structural curve.

The differential effect of cervical kyphosis correction surgery on global sagittal alignment and health-related quality of life according to head- and trunk-balanced subtype.

No reports have investigated how cervical reconstructive surgery affects global sagittal alignment (GSA), including the lower extremities, and health-related quality of life (HRQOL). The study was aimed at elucidating the effects of cervical reconstruction on GSA and HRQOL. Twenty-three patients who underwent reconstructive surgery for cervical kyphosis were divided into a head-balanced group (n = 13) and a trunk-balanced group (n = 10) according to the values of the C7 plumb line, T1 slope (T1S), and pelvic incidence minus lumbar lordosis (PI-LL). Head-balanced patients are those with a negative C7 sagittal vertical axis (SVA), a larger LL than PI, and a low T1S. Trunk-balanced patients are those with a positive SVAC7, a normal PI-LL, and a normal to high T1S. Various sagittal Cobb angles, SVA, and lower-extremity alignment parameters were measured before and after surgery using whole-body stereoradiography. Cervical malalignment was corrected to achieve cervical sagittal balance and occiput-trunk (OT) concordance (center of gravity [COG]-C7 SVA < 30 mm). Significant changes in the upper cervical spine and thoracolumbar spine were observed in the head-balanced group, but no significant change in lumbopelvic alignment was observed in the trunk-balanced group. Lower-extremity alignment did not change substantially in either group. HRQOL scores improved significantly after surgery in both groups. SVACOG-C7 and SVAC2-7 were negatively and positively correlated with the 36-Item Short-Form Health Survey physical component score and Neck Disability Index, respectively. The visual analog scale for back pain, Oswestry Disability Index, and PI-LL mismatch improved significantly in the head-balanced group after cervical reconstruction surgery. Patients with cervical kyphosis exhibited compensatory changes in the upper cervical spine and thoracolumbar spine, instead of in the lower extremities. These compensatory mechanisms resolved reciprocally in a different fashion in the head- and trunk-balanced groups. HRQOL scores improved significantly with GSA restoration and OT concordance following cervical reconstruction.

Factors Negatively Influencing Postoperative Improvement After Laminoplasty in Degenerative Cervical Myelopathy.

This was a retrospective study of prospectively collected data. In this study, we aimed to characterize a population of patients with degenerative cervical myelopathy (DCM) and a history of poor postoperative neurological recovery and to identify risk factors associated with poor neurological recovery after laminoplasty. Kyphotic cervical alignment has been considered a relative contraindication to laminoplasty in recent years; hence, laminoplasty has been decreasingly performed for the treatment of DCM in patients with cervical kyphosis. However, the effect of global spinal alignment on postoperative outcomes has not been extensively investigated. We prospectively enrolled patients who were scheduled for laminoplasty for DCM. Outcome (at enrollment and 1 y after surgery) and risk factor analyses were performed by comparing the good recovery and poor recovery groups. The Spearman correlation coefficient was used to evaluate the relationships between the recovery rate and the preoperative radiographic factors. In total, 101 patients completed the 1-year follow-up. Regarding clinical outcomes, the Japanese Orthopedic Association score for the assessment of cervical myelopathy, European Quality of Life-5 Dimensions, and Neck Disability Index scores improved postoperatively. The recovery rate was significantly correlated with the preoperative sagittal vertical axis (SVA). The patients in the poor recovery group were older than those in the good recovery group. Univariate analyses showed that the SVA and T1 pelvic angle were significantly higher in the poor recovery group. Lastly, stepwise logistic regression analysis showed that a higher SVA was an independent predictor of poor recovery after laminoplasty. The SVA and T1 pelvic angle were significantly higher in the poor recovery group. A high preoperative SVA is an independent predictor for poor recovery after laminoplasty. Therefore, indications for laminoplasty in elderly DCM patients with a high preoperative SVA should be carefully considered. Level III.

Anterior Canal Reconstruction and Fusion for Myelopathy Caused by Degenerative Cervical Kyphosis and Stenosis With or Without Ossification of the Posterior Longitudinal Ligament.

This was a retrospective study. To introduce an anterior surgical technique for myelopathy caused by degenerative cervical kyphosis and stenosis (DCKS) with or without ossification of the posterior longitudinal ligament (OPLL). The optimal approach in the treatment of DCKS remains a controversy because each anterior or posterior route surgery has advantages and disadvantages. In the period from June 2017 through June 2019, a consecutive cohort of adults diagnosed with DCKS underwent anterior canal reconstruction and fusion (ACRF). All patients underwent x-ray, computed tomography, and magnetic resonance imaging of the cervical spine. Radiologic assessment included kyphosis, canal area, canal reconstruction, OPLL, and spinal cord curvature and morphology. The Japanese Orthopaedic Association (JOA) scoring system was used to evaluate the neurological status. Surgery-related and implant-related complications were all recorded. Follow-up was carried out at 3, 6, 12, 24, and 36 months postoperation. Fourty-one patients were included in the study, of which 19 presented with OPLL. Postoperatively, the canal area were significantly greater at last follow-up compared with preoperation (208.4 vs. 123.2 mm2; P=0.001). There was significant kyphosis correction (-17.6 vs. 8.5 degrees, P=0.001) at last follow-up. Ninety-six segmental canal reconstruction were performed, 89 (92.7%) reached bone fusion at both grooves with a mean time of 7.9 months. On sagittal magnetic resonance imaging, 33 (80.5%) patients presented with lordosis in the spinal cord curvature, 8 (19.5%) with straight. The mean JOA score at last follow-up was significantly better than preoperation (15.0 vs. 9.3 points; P<0.01). One patient presented with cerebrospinal fluid leakage, 1 with screw displacement and 2 with dysphagia. ACRF, receiving good correction of kyphosis, amplified canal area, solid instrumented fusion and circumferential decompression, is an effective and safe surgical technique for cervical myelopathy caused by DCKS with or without OPLL. Level III-a retrospective analysis.

Risk Factors and Prevention of C5 Palsy After Anterior Cervical Decompression and Fusion: Similarity of the Pathomechanism With That After a Posterior Approach.

This was a retrospective study. The objective of this study was to review clinical and imaging findings after anterior cervical decompression and fusion, as a basis for prevention of C5 palsy. C5 palsy is a common postoperative complication in spine surgery, but the mechanistic basis for this condition is unknown. The subjects were 239 patients with cervical myelopathy who underwent anterior cervical decompression and fusion including at C4-C5 disk level at our hospital from 2001 to 2018. Twelve of these patients (5.0%) had C5 palsy postoperatively. Clinical features and imaging findings were compared in patients with and without C5 palsy. In patients with C5 palsy, the sagittal alignment of the cervical spine was kyphotic, the width of the C5 intervertebral foramen was narrower, and the lateral decompressed line was wider beyond the medial part of the Luschka joint. Age, sex, disease, the number of fused segments, decompression width, and anterior shift of the spinal cord did not differ significantly between patients with and without C5 palsy. These results indicate that the pathomechanism of C5 palsy may be dependent on the location of the lateral decompression line, especially in patients with cervical kyphosis and a narrow C5 intervertebral foramen. Excessive lateral decompression beyond the Luchka joint might lead to C5 root kinking between the intervertebral foramen and posterior edge of vertebra. This pathomechanism may be similar in anterior and posterior approaches. To prevent C5 palsy, the medial line of the Luschka joint should be confirmed intraoperatively and decompression should be performed within the Luschka joints. Alternatively, medial foraminotomy should be used in cases needing wide decompression, such as those with massive ossification of the posterior longitudinal ligament, lateral osteophytes, and symptomatic foraminal stenosis. Level III.

Correlation between cervical curvature and cervical disc bulging in young patients with neck pain

To explore the correlation between the curvature of the cervical spine and the degree of cervical disc bulging in young patients with cervical pain. The clinical data of 539 young patients with neck pain from January 2015 to December 2018 were retrospectively analyzed. There were 251 males and 288 females, aged 18 to 40 (32.2±6.3) years old. The cervical curvature and cervical disc bulging were measured by cervical X-ray and MRI. According to cervical curvature, the patients were divided into 175 cases of cervical lordosis group (cervical curvature > 7 mm), 163 cases of cervical erection group (0 <cervical curvature ≤ 7 mm), and 201 cases of cervical kyphosis group (cervical curvature ≤ 0 mm). The degreeof cervical intervertebral disc bulging was compared among three groups, and the correlation between cervical curvature and cervical disc bulging was analyzed by Pearson correlation coefficient. The cervical disc bulging of cervical lordosis group, cervical erection group, and cervical kyphosis group were(0.83±0.24), (1.47±0.58), (2.96±1.11) mm, respectively. The degree of cervical disc bulging in cervical lordosis group was less than cervical erection group and cervical kyphosis group(P<0.05). Pearson correlation analysis showed that the degree of cervical disc bulging was significantly negatively correlated with cervical curvature(R=-0.561, P<0.05). The degree of cervical disc bulging in young patients with neck pain is closely related to the reduction of cervical curvature.

Biomechanics of Circumferential Cervical Fixation Using Posterior Facet Cages: A Cadaveric Study.

ObjectiveAnterior cervical discectomy and fusion (ACDF) is a common procedure for the treatment of cervical disease. Circumferential procedures are options for multilevel pathology. Potential complications of multilevel anterior procedures are dysphagia and pseudarthrosis, whereas potential complications of posterior surgery include development of cervical kyphosis and postoperative chronic neck pain. The addition of posterior cervical cages (PCCs) to multilevel ACDF is a minimally invasive option to perform circumferential fusion. This study evaluated the biomechanical performance of 3-level circumferential fusion with PCCs as supplemental fixation to anteriorly placed allografts, with and without anterior plate fixation. MethodsNondestructive flexibility tests (1.5 Nm) performed on 6 cervical C2–7 cadaveric specimens intact and after discectomy (C3–6) in 3 instrumented conditions: allograft with anterior plate (G+P), PCC with allograft and plate (PCC+G+P), and PCC with allograft alone (PCC+G). Range of motion (ROM) data were analyzed using 1-way repeated-measures analysis of variance. ResultsAll instrumented conditions resulted in significantly reduced ROM at the 3 instrumented levels (C3–6) compared to intact spinal segments in flexion, extension, lateral bending, and axial rotation (p < 0.001). No significant difference in ROM was found between G+P and PCC+G+P conditions or between G+P and PCC+G conditions, indicating similar stability between these conditions in all directions of motion. ConclusionAll instrumented conditions resulted in considerable reduction in ROM. The added reduction in ROM through the addition of PCCs did not reach statistical significance. Circumferential fusion with anterior allograft, without plate and with PCCs, has comparable stability to ACDF with allograft and plate.

The association between cervical focal kyphosis and myelopathy severity in patients with cervical spondylotic myelopathy before surgery.

Cervical focal kyphosis could often be observed in patients with cervical spondylotic myelopathy (CSM). However, the association between it and myelopathy severity remains unclear. This study aims to elucidate the association between cervical focal kyphosis and myelopathy severity before surgery. A retrospective review of 191 consecutive patients treated for CSM from 2017 to 2019 was surveyed. Seven MRI and five radiographic parameters were measured, clinical parameters were included. Patients were divided into two sagittal focal angle groups (lordosis/kyphosis) and two disc herniation severity groups (severe/non-severe). The potential risk factors of myelopathy symptoms were analysed. Significant correlations between cervical sagittal focal angles, several other imaging findings and myelopathy severity were found in both total patients (R2 = 0.51, P < 0.001) and non-severe disc herniation patients (R2 = 0.73, P < 0.001) in multivariate regression models. Compression ratio of spinal cord exhibited the strongest correlation with JOA scores (r = -0.567, P < 0.001). Cervical focal angles on MRI exhibited a stronger negative correlation with JOA scores (r = -0.429, P < 0.001) than did angles on the other three postures on radiographs. Dramatic differences in JOA scores could be found in patients with non-severe cervical disc herniation, when a subgroup analysis was performed between cervical lordosis group and more than 4° kyphosis group (14.2 ± 1.7 vs. 11.1 ± 1.7, P < 0.001). Cervical focal kyphosis associates with severe myelopathy symptoms in patients with CSM, especially without severe disc herniation. This association may indicate an optimal cervical focal angle in surgical plan. It appeared feasible to assess both the cervical focal angles and spinal cord compression on supine MRI.