Kyphotic Alignment Research Articles

P108. Impact of C3 involvement on postoperative kyphosis following cervical laminoplasty: Comparison between high and low T1 slope

<h3>BACKGROUND CONTEXT</h3> The impact of T1 slope (T1S) has emerged as a predictor of kyphotic alignment change after laminoplasty. Although it was reported that higher T1S had more pronounced lordotic curvature before surgery and higher loss of cervical lordosis (CL) after surgery, few studies have attempted to investigate these findings with the extent of laminoplasty. <h3>PURPOSE</h3> The goals of the present study were to investigate the impact of C3 involvement on the kyphosis following cervical laminoplasty in patients with high and low T1 slope. <h3>STUDY DESIGN/SETTING</h3> The data from ossification of the posterior longitudinal ligament (OPLL) patients who had undergone laminoplasty between January 2016 and January 2019 were retrospectively reviewed. <h3>PATIENT SAMPLE</h3> Patients were divided into two groups according to preoperative T1 slope, and subgroup analysis was done according to the C3 involvement in performing laminoplasty. <h3>OUTCOME MEASURES</h3> The involvement of C3 segment in performing laminopalsty, C1-2 angle, C0-2 angle, cervical lordosis and T1 slope was measured and compared. <h3>METHODS</h3> Univariate tests and multivariate logistic regression analysis were used to assess the statistical relationship between postoperative kyphosis and radiological and surgical variables. <h3>RESULTS</h3> Eighty-six patients were divided into two groups above and below preoperative T1S (20.0°). There were 33 patients (38.3%) in low T1S group and 53 patients (61.7%) in high T1S group. Twenty-three patients (26.7%) were performed with C3 involved laminoplasty. In multivariate logistic regression analysis, C3 involvement (OR; 9.671, 2.820-33.158, p=0.000), high T1S (OR; 4.888,1.543-15.487, p=0.007) and low T1S-CL (OR; 0.128, 0.037-0.449, p=0.001) were significantly associated with postoperative kyphosis. In the subsequent subgroup analysis, C3 involvement was emerged as independent risk factor in high T1S group, increasing the odds of postoperative kyphosis by 27.315 -fold (1.560-478.282, p=0.024). In high T1S group, the loss of CL was greater (p = 0.017) when C3 was involved whereas in low T1S group, the C3 involvement did not show the statistically significant difference in the change of CL (p = 0.190). <h3>CONCLUSIONS</h3> C3 involvement, low T1S-CL and high T1S increased the risk of postoperative kyphosis. Patients with high T1 slope tended to exbibit a greater loss of CL when the laminoplasty was performed extending to C3 segment. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

126. Proximal and distal reciprocal alignment changes following cervical deformity correction

<h3>BACKGROUND CONTEXT</h3> Hyperextension of C0-C2 is a painful compensatory mechanism used to maintain horizontal gaze that is analogous to high pelvic tilt to maintain upright posture. The magnitude and impact of relaxation of this hyperextension following CD correction are not well understood. <h3>PURPOSE</h3> To investigate whether correction of cervical sagittal malalignment allows for relaxation of C0–C2 hyperextension and improved clinical outcome. <h3>STUDY DESIGN/SETTING</h3> Retrospective review. <h3>PATIENT SAMPLE</h3> This study included 65 ACD patients with 1- or 2-year follow-up. <h3>OUTCOME MEASURES</h3> Radiographic alignment, range of motion (ROM). <h3>Methods</h3> CD patients undergoing surgery short of the occiput and the pelvis were included. In addition to the classic alignment parameters, ROM and reserve of extension were calculated across the C2-C7 and C0-C2 segments. After describing the cohort in terms of preoperative information, correlations and hierarchical stepwise regressions investigated the association between C2-C7 correction and change in C0-C2 reserve of extension while controlling for maintenance of horizontal gaze. Stratification by ΔC2-C7 percentile was conducted followed by paired t-tests to investigate changes in TK, C0-C2 and reserve of extension within each percentile. <h3>Results</h3> Sixty-five patients were included (61.8yo±9.6, 68%F). At baseline, they presented with a cervical kyphotic alignment (C2-C7: -11.7°±18.2; TS-CL: 38.6°±18.6), a negative global alignment (SVA: -12mm±71), and hyperlordosis at C0-C2 (33.2°±11.8). The ROM was 25.7°±17.7 and 21.3°±9.9 at C2-C7 and C0-C2, respectively, with an associated reserve of extension of ∼9° for each segment. Limited C0-C2 ROM and reserve of extension significantly correlated with the Neck Disability Index (r=-0.371 & -0.394) and with decreased general health (r=0.455 & 0.512) (all p<0.005) The mean number of levels treated was 7.0±3.1 (24.6% ACDF, 43.1% posterior), with 49.2% of the patients receiving an osteotomy, and 16.9% a 3CO. At 1 year, C2-C7 increased to 5.5°±13.4, SVA became neutral (12mm±54), C0-C2 decreased to 27.7°±11.7, and TK increased to -49.4±18.1 (all p <0.001). At C2-C7 ROM decreased significantly to 9.5°±14.1, and increased to 27.6°±8.1 at C0-C2 without change in reserve of extension. The horizontal gaze significantly improved (4.5±13.3 vs -0.5±9.3 p=0.003). Controlling horizontal gaze, change in C2-C7 lordosis significantly correlated with increased TK (r=-0.615, p<0.01), decreased C0-C2 (r=-0.686, p<0.001), and increased C0-C2 reserve of extension (r=0.414, p<0.015). Larger C0-C2 ROM and reserve of extension correlated with decreased in Neck Disability Index (r=-0.571 & -0.470 p<0.05). Stratification by ΔC2-C7 percentile highlighted the reciprocal change above and below the fusion. Within the lowest percentile (ΔC2-C7: 2°±9.6), no significant difference was noticed between pre and 1 year, while within the highest percentile (ΔC2-C7: -42.8±14.1), C0-C2 decreased (-9.7°±10.5, p=0.001), TK kyphosis increased (14.3°±7.5, p<0.001) and C0-C2 reserve of extension increased (5.8°±6.4, p=0.026). Subanalysis on patients with available 2-year data (N=42) demonstrated similar trends. <h3>Conclusions</h3> Correction of cervical malalignment can significantly impact proximal (C0-C2) and distal (T2-T12) compensation. Restoration of a more natural alignment resulted in an increase of the reserve of extension between C0-C2 and was associated with improved clinical outcomes. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Sagittal body alignment in a sitting position in children is not affected by the generalized joint hypermobility

Back pain may be related to an improper sitting position. The aim of the study was to assess the sagittal curvatures of the spine in a sitting position in children with generalized joint hypermobility (GJH). The study included 302 children aged 8–14 years. The sagittal curvatures of the spine (sacral slope, lumbar lordosis, thoracic kyphosis with its lower and upper part) were assessed using the Saunders digital inclinometer. In order to assess GJH a 9-point Beighton scale was used. The study revealed no significant differences (p > 0.05) in sagittal curvatures of the spine in a relaxed sitting position between children with and without GJH. Regardless of the occurrence of GJH, kyphotic alignment of the spine was noted in a relaxed sitting. GJH does not affect the position of the trunk in a sagittal plane in a relaxed sitting position in children aged 8–14 years. A relaxed sitting position in children with and without GJH is characterized by a kyphotic position of the spine caused by an improper position of pelvis and lumbar segment of the spine.

Preoperative Radiological Parameters to Predict Clinical and Radiological Outcomes after Laminoplasty.

Many studies have focused on pre-operative sagittal alignment parameters which could predict poor clinical or radiological outcomes after laminoplasty. However, the influx of too many new factors causes confusion. This study reviewed sagittal alignment parameters, predictive of clinical or radiological outcomes, in the literature. Preoperative kyphotic alignment was initially proposed as a predictor of clinical outcomes. The clinical significance of the K-line and K-line variants also has been studied. Sagittal vertical axis, T1 slope (T1s), T1s-cervical lordosis (CL), anterolisthesis, local kyphosis, the longitudinal distance index, and range of motion were proposed to have relationships with clinical outcomes. The relationship between loss of cervical lordosis (LCL) and T1s has been widely studied, but controversy remains. Extension function, the ratio of CL to T1s (CL/T1s), and Sharma classification were recently proposed as LCL predictors. In predicting postoperative kyphosis, T1s cannot predict postoperative kyphosis, but a low CL/T1s ratio was associated with postoperative kyphosis.

Clinical Effects of Preoperative K-Line Tilt on Patient Outcomes After Laminoplasty for Cervical Ossification of the Posterior Longitudinal Ligament

We sought to clarify the effects of the preoperative K-line tilt on cervical sagittal balance and patient outcomes after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). A retrospective analysis of 45 patients with OPLL treated by laminoplasty from January 2013 to December 2018 was performed. The radiological parameters included the K-line tilt, C2-C7 sagittal vertical axis, C2-C7 lordosis, T1 slope, and T1 slope minus C2-C7 lordosis. The patient quality of life outcomes were assessed using the neck disability index, Japanese Orthopaedic Association disability scale, and visual analog scale. The patients were classified into 2 groups according to the median preoperative K-line tilt angle (14.1°): the high K-line tilt group (n= 23) and the low K-line tilt group (n= 22). The postoperative cervical alignment changes and patient outcomes were compared and analyzed. The clinical outcomes demonstrated overall improvement at the final follow-up. The C2-C7 lordosis had significantly decreased from 13.5° ± 9.5° preoperatively to 10.2° ± 9.7°. The C2-C7 lordosis was less in the high K-line tilt group than that in the low K-line tilt group. In addition, the high K-line tilt group revealed significantly greater kyphotic changes and a greater loss of cervical lordosis compared with the low K-line tilt group. Finally, the quality of life outcomes and postoperative visual analog scale scores were higher in the high K-line tilt group. The results of the present study have shown that the parameter K-line tilt is an ideal radiological parameter for predicting the outcomes and determining the need for laminoplasty for cervical ossification of the OPLL. Patients with a higher K-line tilt preoperatively experienced more kyphotic alignment changes and neck pain after laminoplasty.

Significance of Vertebral Body Sliding Osteotomy as a Surgical Strategy for the Treatment of Cervical Ossification of the Posterior Longitudinal Ligament.

Study Design:Retrospective cohort study.Objectives:Vertebral body sliding osteotomy (VBSO) has previously been reported as a technique to decompress ossification of the posterior longitudinal ligament (OPLL) by translating the vertebral body anteriorly. This study aimed to evaluate the radiological and clinical efficacies of VBSO and clarify the surgical indications of VBSO for treating myelopathy caused by OPLL.Methods:Ninety-seven patients with symptomatic OPLL-induced cervical myelopathy treated with VBSO or laminoplasty who were followed up for more than 2 years were retrospectively reviewed. Cervical alignment, range of motion, fusion, modified K-line (mK-line) status, and minimum interval between ossified mass and mK-line (INT(min)), and the Japanese Orthopaedic Association (JOA) score were assessed. Patients in the VBSO group were compared with those who underwent laminoplasty.Results:Cervical lordosis and INT(min) significantly increased in the VBSO group. All patients in the VBSO group assessed as mK-line (-) preoperatively were assessed as mK-line (+) postoperatively. However, in the LMP group, the mK-line status changed from (+) preoperatively to (−) postoperatively in 3 patients. Final JOA score (p = 0.02) and JOA score improvement (p = 0.01) were significantly higher in the VBSO group. JOA recovery ratio (p = 0.03) and proportion of patients with a recovery rate ≥50% were significantly higher in the VBSO group (p < 0.01).Conclusions:VBSO is an effective surgical option for OPLL-induced myelopathy, demonstrating favorable neurological recovery and lordosis restoration with low complication rates. It is best indicated for kyphotic alignment, OPLL with a high space-occupying ratio, and OPLL involving ≤3 segments.

Medialization of Common Carotid Artery Is Associated with Cervical Kyphosis.

Introduction Reportedly, the medialization of the common carotid artery (MCCA) to be a vascular anomaly with a potential risk of intraoperative carotid artery injury. Nevertheless, among spine surgeons, the presence of MCCA has not been well recognized. Methods We retrospectively reviewed consecutive patients who underwent cervical radiographs and magnetic resonance imaging (MRI) examinations in a single spine center. Using MRI, the MCCA grade was classified into grades 1 to 3 in order of severity. Radiographic measurement included C2-C7 angles as cervical lordosis, cervical sagittal vertical axis (C-SVA), T1 slope (T1S), and T1S-cervical lordosis mismatch. We compared each patient's background and radiographic parameters between patients with each of the three MCCA grades. The continuous variables were compared using the Jonckheere-Terpstra trend test and the proportions were compared using the Cochran-Armitage trend test to investigate the trend of variables in three grades. Results The present study included data from 133 eligible patients (65 males and 68 females) with a mean age of 63.7 (±14.2) years. The details of MCCA grading were as follows: grade 1, n=101; grade 2, n=27; and grade 3, n=5. With an increasing MCCA grade, age (61.9±14.0, 68.2±13.8, and 76.4±9.4 years for grades 1, 2, and 3, respectively, p=0.005) and proportion of female (p<0.001) had an increasing trend, whereas cervical lordosis had a decreasing trend (11.7±13.5°, 7.0±14.5°, and −10.0±19.2° for grades 1, 2, and 3, respectively, p=0.011). Conclusions Several patient backgrounds including the female gender, older age, and kyphotic alignment were determined as MCCA risk factors. Careful preoperative neck vasculature assessment would avoid a catastrophic complication during anterior cervical surgery.

Influence of cervical spine sagittal alignment on range of motion after corpectomy: a finite element study.

Sagittal alignment of the cervical spine might influence the development of radiological adjacent segment pathology (RASP) after central corpectomy (CC). Range of motion (ROM) of the adjacent segments is closely linked to the development of RASP. To investigate the ROM of the adjacent segments after CC, we developed a C2-T1 finite element (FE) model. The model with a lordotic sagittal alignment served as the baseline model. Models with straight and kyphotic alignment were generated using mesh morphing methods. Single-level corpectomy at C5 was done on these models. Segmental ROMs of intact and corpectomized spines were compared for physiologic flexion-extension loads. The flexion ROM decreased by an average of 13% with the change in sagittal alignment from lordosis to kyphosis; however, a consistent decrease was not observed in extension. After CC, the ROM increased by an average of 95% and 31% in the superior and inferior adjacent segments. With kyphotic change in the sagittal alignment, the postoperative increase in flexion ROM exhibited a decreasing trend, while this was not seen in extension. Kyphotic changes of the intact spine resulted in segmental stiffening, and after corpectomy, it resulted in inconsistent variations of segmental extension ROMs.

The Impact of Anterior Spondylolisthesis and Kyphotic Alignment on Dynamic Changes in Spinal Cord Compression and Neurological Status in Cervical Spondylotic Myelopathy: A Radiological Analysis Involving Kinematic CT Myelography and Multimodal Spinal Cord Evoked Potentials.

A retrospective study of prospectively collected data. This study aimed to examine how radiological parameters affect dynamic changes in the cross-sectional area of the spinal cord (CSA) in cervical spondylotic myelopathy (CSM) patients and how they correlate with the severity of myelopathy, by evaluating multi-modal spinal cord evoked potentials (SCEPs). Appropriate assessments of dynamic factors should reveal hidden spinal cord compression and provide useful information for choosing surgical procedures. Seventy-nine CSM patients were enrolled. They were examined with kinematic CT myelography (CTM), and the spinal levels responsible for their CSM were determined via SCEP examinations. The C2-7 angle, C2-7 range of motion, and percentage of slip were measured on the midsagittal view during flexion and extension, and the CSA was measured on the axial view in each neck position using kinematic CTM. The patients who exhibited the smallest CSA values during extension and flexion were classified into Groups E and F, respectively. Fifty-two (65.8%) and 27 (34.2%) cases were included in Groups E and F, respectively. The preoperative JOA score did not differ significantly between the groups; however, the preoperative lower-limb JOA score of Group F was significantly lower than that of Group E (2.24 ± 0.82 vs. 2.83 ± 1.09, P = 0.016). In the multiple logistic regression analysis, a small C2-7 angle during extension (β = 5°, odds ratio: 0.69, 95% confidence interval [CI]: 0.54-0.90) and the slip percentage during flexion (β = 5%, odds ratio: 1.42, 95% CI: 1.09-1.85) were identified as significant predictors of belonging to Group F. Exhibiting more severe spinal cord compression during neck flexion was associated with a small C2-7 angle and anterior spondylolisthesis. The neurological status of the patients in Group F was characterized by severe lower limb dysfunction because of a disturbed blood supply to the anterior column.Level of Evidence: 4.

Nomogram for predicting kyphotic deformity after laminoplasty in cervical spondylotic myelopathy patients without preoperative kyphotic alignment

BackgroundKyphotic deformity occurrence after cervical laminoplasty is not rare. Several studies have emphasized the development of postoperative kyphotic deformity (PKD) will impair the functional outcome of cervical laminoplasty. We established and validated a nomogram prediction model for kyphotic deformity after laminoplasty in cervical spondylotic myelopathy patients (CSM) without preoperative kyphotic alignment. MethodsPreoperative and 1-year postoperative data of 369 patients who underwent single-door cervical laminoplasty (SDCL) at the author’s hospital between July 2010 and February 2018 were collected. Using the least absolute shrinkage and selection operator (LASSO) method, significant parameters were selected to develop a nomogram prediction model. The prognostic performance of the model was evaluated using concordance index (C-index) and calibration curve. The discriminatory ability of the prediction model was evaluated by the area under (receiver operating characteristic) curve (AUC). ResultsOf the 369 patients, 31 developed PKD in 1 year after the surgery. Using the LASSO regression, six significant variables composed the final model: age, C2-7 sagittal vertical axis, C7 slope, C2-7 angle, flexion range of motion and operation level were selected. The AUC of the nomogram was 0.771. The C-index for the prediction nomogram was 0.771 (95 % CI: 0.672−0.870). The calibration curve also indicated good consistency. ConclusionA nomogram for predicting PKD after SDCL was established and validated. For patients evaluated by this model with predictive high risk of developing postoperative kyphosis, an alternative approach to the subaxial cervical spine such as anterior surgery should be considered.

Comparison of Clinical and Radiographic Outcomes of Laminoplasty, Anterior Decompression With Fusion, and Posterior Decompression With Fusion for Degenerative Cervical Myelopathy: A Prospective Multicenter Study.

Prospective multicenter study. The aim of this study was to compare the clinical and radiographic results of laminoplasty (LAMP), anterior decompression with fusion (ADF), and posterior decompression with fusion (PDF) for degenerative cervical myelopathy (DCM). Although ADF, LAMP, and PDF have been performed for DCM, little is known about the difference in impact of these surgical treatments on clinical and radiographic outcomes. We prospectively enrolled patients who were scheduled for surgery for DCM and compared the clinical and radiographic results of ADF, LAMP, and PDF. In total, 171 patients completed the 1-year follow-up. Regarding clinical outcomes, the Japanese Orthopedic Association score for the assessment of cervical myelopathy (C-JOA score), European Quality of Life-5 Dimensions (EQ-5D), and Neck Disability Index (NDI) scores improved in all groups postoperatively. However, no significant differences were found in C-JOA, EQ-5D, and NDI scores and recovery rate among the groups. Regarding radiographic parameters, although the operation had no effect on cervical lordosis (CL) and the C2-7 sagittal vertical axis (SVA) in the ADF group, they worsened in the LAMP and PDF group. Although there were no significant differences in any preoperative radiographic parameters within the ADF and LAMP group, CL was significantly lower and the C2-7 SVA was significantly higher in the nonrecovery group within the PDF group. Logistic regression analysis showed that preoperative lower CL was an independent risk factor for poor recovery in the PDF group. Although groups showed no significant differences in clinical outcomes, cervical alignment worsened after surgery in the LAMP and PDF groups. Within the PDF group, lower CL was an independent risk factor for poor recovery. Therefore, the indications for PDF in DCM patients with preoperative kyphotic alignment should be carefully considered. 3.

Analysis of Cervical Spine Alignment and its Relationship with Other Spinopelvic Parameters After Laminoplasty in Patients with Degenerative Cervical Myelopathy.

For patients with kyphosis of the cervical spine, laminoplasty is usually incapable of improving neurological symptoms as it worsens kyphotic alignment. Thus, laminoplasty is not recommended in the presence of kyphotic alignment. Nevertheless, laminoplasty may be selected for myelopathy due to multiple-segment intervertebral disc herniation or ossification of posterior longitudinal ligament despite kyphotic alignment. This study examined whether cervical alignment influences surgical outcomes. Cervical alignment before the surgery was classified into lordosis and non-lordosis, and the non-lordosis group was subclassified into reducible and non-reducible groups to determine the change in cervical alignment before and after the surgery and to analyze its relationship with spinopelvic parameters. The lordosis group showed an increase in upper cervical motion (C0-2 Range of Motion (ROM), C0-2ROM/C0-7ROM) after surgery, while the non-lordosis group exhibited a decrease in C2-7ROM and C0-7ROM. The C0-2ROM was maintained without any reduction in the reducible group, while there was no significant change in cervical alignment and ROM of the non-reducible group. None of these changes showed significant association with the spinopelvic parameters of other sites. However, having a non-reducible type non-lordosis is not a proper indication for laminoplasty, as it does not change the alignment after surgery. Therefore, cervical alignment and reducibility should be identified before surgery.

Cervical laminoplasty: indication, technique, complications.

Cervical laminoplasty is a non-fusion, decompression procedure for cervical spondylotic myelopathy (CSM). It is most commonly indicated for patients with multilevel stenosis who have preserved sagittal alignment and minimal to no axial neck pain related to spondylosis. Expansion of the laminar arch can allow for direct and indirect decompression of the spinal canal. Relative contraindications include those patients with significant preoperative neck pain, kyphotic alignment and substantial instability. Potential advantages over laminectomy and fusion include avoiding fusion-related complications, and the preservation of motion. Important technical considerations include meticulous extensor muscle management, with special attention being given to preserving the soft tissue attachments to C2. In the properly selected patient, outcomes are comparable, and in some studies superior, to other operations for CSM.

Factors predicting loss of cervical lordosis following cervical laminoplasty: A critical review

Background:Laminoplasty is a method of posterior cervical decompression which indirectly decompresses the spinal column. Unfortunately, many patients undergoing laminoplasty develops postoperative loss of cervical lordosis (LCL) or kyphotic alignment of cervical spine even though they have sufficient preoperative lordosis which results in poor surgical outcome.Objective:We would like to highlight the relationship between various radiological parameters of cervical alignment and postoperative LCL in patients undergoing laminoplasty.Methods:We performed extensive literature search using PubMed, Google Scholar, and Web of Science for relevant articles that report factors affecting cervical alignment following laminoplasty.Results:On reviewing the literature, patients with high T1 slope have more lordotic alignment of cervical spine preoperatively. They also have more chances of LCL following laminoplasty. C2–C7 sagittal vertical axis (SVA) has no role in predicting LCL following laminoplasty though patients with low T1 slope (≤20°) and high C2–C7 SVA (>22 mm) had correction of kyphotic deformity following laminoplasty. C2–C7 lordosis, Neck Tilt, cervical range of motion, and thoracic kyphosis has no predictive value for LCL. Lower value of T1 slope (T1S-CL) and CL/T1S has more incidence of developing LCL following laminoplasty. The role of C2–C3 disc angle has not yet been evaluated in patients undergoing laminoplasty. Dynamic extension reserve determines the contraction reserve of SPMLC and lower dynamic extension reserve is associated with higher chances of LCL following laminoplasty.Conclusions:Cervical lordotic alignment is important in maintaining cervical sagittal balance which ultimately is responsible for global spinal sagittal balance and horizontal gaze. Among various radiological parameters, T1 Slope has been reported to be the most important factor affecting cervical alignment following laminoplasty.

Spinal kyphotic alignment changes spinal movement strategy during lateral reaching motion while in a sitting position.

[Purpose] This study investigated spine kinematics during normal sitting and flexion sitting with lateral reaching using a three-dimensional motion analysis system. [Participants and Methods] Nineteen healthy young adult males participated in this study. While seated, each participant was asked to reach toward the right using his right hand. Spine angles were defined as T1, T4, T8, L1, and L5 segments. Kinematic data were calculated using the Euler angle and compared to normal sitting and flexion sitting. During flexion sitting, each participant wore a trunk flexion brace. [Results] In the frontal plane, the angle of the T8 segment during flexion sitting was significantly less than during normal sitting. In the axial plane, there were significant differences among the T4, L1, and L5 segments. [Conclusion] Changes in spinal alignment decrease spinal movement and change the movement strategy during lateral reaching while seated.

The impact of plating level on the postoperative loss of cervical lordosis in alternative skipped-level plating laminoplasty.

The aim of this study is to evaluate the impact of plating level on the loss of cervical lordosis (LCL) after laminoplasty with skipped-level plating. This retrospective study included patients who underwent alternative skipped-level plating laminoplasty from C3 to C6. Patients were divided into two groups according to the plating level. Group 1 had miniplate fixed at C3 and C5 (C3/C5 group), while patients in group 2 were fixed at C4 and C6 (C4/C6 group). The outcome of interest was the difference of LCL between the two groups; meanwhile, kyphosis development after laminoplasty was also compared. A total of 70 patients were included in our study with a mean age of 60.44 ± 9.97 years. The median follow-up was 15 (12, 16) months. Median lordosis was 15.43° (9.35°, 22.23°) before surgery and 9.88° (4.15°, 18.94°) after, with a median LCL of 4.48° (-0.66°, 8.11°). There were 17 patients in the C3/C5 group, whereas 53 patients in the C4/C6 group. While preoperative C2-C7 Cobb's angle was comparable between the two groups (15.32° (9.73°, 23.84°) vs. 15.51° (9.03°, 21.70°), p = 0.864), there were statistical differences regarding postoperative C2-C7 Cobb's angle (6.54° (2.49°, 16.42°) vs. 10.62° (5.89°, 18.85°), p = 0.006) and LCL (4.74° (4.17°, 12.03°) vs. 4.07° (-1.89°, 6.69°), p = 0.034) between the C3/C5 group and the C4/C6 group. In all, 94.1% (16 of 17) of patients showed some degree of LCL after laminoplasty in the C3/C5 group, which was significantly higher when compared with 64.2% (34 of 52) of C4/C6 group (p = 0.038). Before surgery, there were no kyphosis patients in either the C3/C5 group or the C4/C6 group. Postoperatively, four patients (23.5%) developed kyphotic alignment in the C3/C5 group, but only one (1.9%) in the C4/C6 group (p = 0.013). Cervical alignment was compromised after laminoplasty. When alternative skipped-level plating is adopted in laminoplasty from C3 to C6, plating at C4/C6 may better preserve cervical lordosis than plating at C3/C5 after surgery.

Impact of cervical sagittal parameters and spinal cord morphology in cervical spondylotic myelopathy status post spinous process-splitting laminoplasty.

No standard strategy exists for managing cervical spondylotic myelopathy (CSM). The efficacy of spinous process-splitting laminoplasty, its impact on cervical alignment change and the incidence of postoperative neck pain remain unclear. We analyzed the parameters of cervical alignment and cord morphology in CSM. The radiographic parameters investigated were pre- and postoperative C2-C7 lordosis (CL), C2-C7 sagittal vertical axis (CSVA), T1 slope (TS), TS minus CL (TS - CL) and cervical spinal cord morphology. Myelopathy severity was measured using two different functional scores. Statistical analysis was performed to determine significant differences between preoperative and follow-up radiological findings and change in functional scores. This retrospective study comprised 85 CSM patients from a single institute, with a minimum follow-up of 24months. Overall, 63.5% (n = 54) of patients had improvement in their postoperative cervical lordotic alignment; 36.5% (n = 31) developed progressive aggravation of the cervical kyphotic alignment. Pearson correlation analysis showed that CSVA, TS and T1-CL were independent predictors of CL curve change. Based on the receiver operating characteristic curve, the cutoff value for CSVA was 2.89cm with a postoperative visual analog scale (VAS) > 4. The cutoff value of the TS - CL was 20 degrees with a postoperative VAS > 4. CSVA, TS and TS - CL had a significant association with variation in CL. CSVA and TS - CL had a significant association with postoperative neck pain. CSVA, T1 slope and T1-CL are good predictors of postoperative degenerative kyphotic change and neck pain. Careful consideration of their preoperative cutoff values can improve postoperative outcomes. IV. These slides can be retrieved under Electronic Supplementary Material.

Postoperative Kyphosis in Cervical Spondylotic Myelopathy: Cut-off Preoperative Angle for Predicting the Postlaminoplasty Kyphosis.

A prospective cohort study. This study aimed to investigate the relationship between preoperative cervical sagittal alignment and postoperative kyphosis in patients with cervical spondylotic myelopathy (CSM) and to determine the cut-off angle for predicting the postlaminoplasty kyphosis. There have been several reports describing a cervical kyphosis after laminoplasty. However, there has been no study on the cut-off angle for predicting the postoperative kyphosis in a large series of patients with CSM. A total of 1025 consecutive patients with CSM (642 men and 383 women; mean age, 64.4 yr; range, 23-93 yrs) who underwent laminoplasty were included. The average follow-up period was 30.0 months. Radiography was performed before the surgery and at final follow-up. The cervical alignment with neutral view was measured by using the Cobb method. An alignment of C2-7 lordotic angle more than 0° was defined as lordosis and C2-7 lordotic angle less than 0° was defined as kyphosis. The incidence of postoperative kyphosis was evaluated on lateral radiographs. In all patients, the mean C2-7 alignment in the neutral position was 11.5° lordotic before surgery and 14.2° lordotic at final follow-up. In the patient without preoperative kyphotic alignment, receiver operating characteristic curve of preoperative C2-7 lordotic angle showed 7° as a predictor for the postlaminoplasty kyphosis (area under the curve = 0.75, P < 0.0001). Among the preoperatively 720 patients with lordosis more than 7°, postoperative kyphosis was observed in 20 patients (2.8%), whereas in the preoperatively 191 patients with lordosis less than 7°, postoperative kyphosis was seen in 28 patients (14.7%). The cut-off value of preoperative C2-7 lordotic angle for predicting the postlaminoplasty kyphosis was 7° in CSM patient without preoperative kyphotic alignment. 3.

Multivariate analysis of poor outcome after anterior surgery in multilevel cervical spondylotic myelopathy patients with heterotopic ossification and preoperative kyphotic alignment.

ObjectiveThe aim of this study was to evaluate the risk factors for poor outcome in patients who underwent multi-segmental anterior surgery, and analyze postoperative complications.MethodsWe retrospectively reviewed 158 patients after anterior surgery due to multilevel cervical spondylotic myelopathy (m-CSM) between June 2008 and June 2016. Adjusted ORs and 95% CIs were determined by multivariate logistic regression analysis. Cutoff values and the area under the curve for continuous risk factors were calculated through receiver operating characteristic curve analysis. The chi-squared test was performed for the comparison of complications among the three surgical groups.ResultsBy analyzing 105 patients with good outcome and 53 patients with poor outcome, we established that the risk factors for poor outcome were advanced age (OR =1.12, P=0.003), longer duration of symptoms (OR =1.07, P=0.028), and bigger kyphotic angle at final follow-up (OR =1.29, P< 0.001). The optimal cutoff values for age, duration of symptoms, and kyphotic angle at final follow-up were 63.1 years, 15.5 months, and 5.3 angle. Postoperative complications occurred in 21 patients (13.3%). The incidence of dysphagia and cerebrospinal fluid leakage were higher in multilevel anterior cervical discectomy and fusion (m-ACDF) group than in other groups (P< 0.05).ConclusionAdvanced age, longer duration of symptoms, and bigger kyphotic angle at final follow-up were the risk factors for poor postoperative outcome in patients with m-CSM. The complications after hybrid approach and m-ACDF approach were less than after anterior cervical corpectomy and fusion approach.

Which factors predict the loss of cervical lordosis following cervical laminoplasty? A review of various indices and their clinical implications.

Background:Many patients undergoing laminoplasty develop postoperative loss of cervical lordosis or kyphotic alignment of cervical spine despite sufficient preoperative lordosis. This results in poor surgical outcomes.Methods:Here, we reviewed the relationship between multiple radiological parameters of cervical alignment that correlated with postoperative loss of cervical lordosis in patients undergoing laminoplasty.Results:Patient with a high T1 slope (T1S) has more lordotic alignment of the cervical spine preoperatively and is at increased risk for the loss of cervical lordosis postlaminoplasty. Those with lower values of difference between T1S and Cobb’s angle (T1S-CL) and CL-T1S ratio have higher risks of developing a loss of the cervical lordosis postoperatively. Alternatively, C2-C7 lordosis, neck tilt, cervical range of motion, and thoracic kyphosis had no role in predicting the postlaminoplasty kyphosis.Conclusion:Among various radiological parameters, the preoperative T1S is the most important factor in predicting the postoperative loss of the cervical lordosis/alignment following laminoplasty.