Article

Spinal kyphosis causes demyelination and neuronal loss in the spinal cord: a new model of kyphotic deformity using juvenile Japanese small game fowls

December 2005
Spine 30(21):2388-92

Source
PubMed

Authors:

Keio University

Histologic changes in the spinal cord caused by progressive spinal kyphosis were assessed using a new animal model. To evaluate the effects of chronic compression associated with kyphotic deformity of the cervical spine on the spinal cord. The spinal cord has remarkable ability to resist chronic compression, however, delayed paralysis is sometimes seen following the development of spinal kyphosis. In the past, no animal model to clarify the mechanism of spinal cord damage due to spinal kyphotic deformity has been available. Laminectomy and bilateral facetectomy at the C4-C5 level was performed in 52 Japanese small game fowls. Histologic changes in the spinal cord associated with progressive kyphotic deformity were examined at different time points after surgery in each animal. The degree of spinal cord flattening and the severity of demyelination in histologic sections were quantitatively evaluated using an image analyzer, and their association with the kyphotic angle was analyzed. Changes in the microvascular distribution in the spinal cord were also examined by microangiography. In all operated animals, progressive kyphosis developed reproducibly. The kyphotic angle increased gradually until 3 weeks after surgery and stabilized thereafter. There was a significant correlation between the kyphotic angle and the degree of spinal cord flattening. The spinal cord was compressed most intensely at the apex of the kyphosis, where demyelination of the anterior funiculus as well as neuronal loss and atrophy of the anterior horn were observed. Demyelination progressed as the kyphotic deformity became more severe, initially affecting the anterior funiculus and later extending to the lateral and then the posterior funiculus. Angiography revealed a decrease of the vascular distribution at the ventral side of the compressed spinal cord. Progressive kyphosis of the cervical spine resulted in demyelination of nerve fibers in the funiculi and neuronal loss in the anterior horn due tochronic compression of the spinal cord. These histologic changes seem to be associated with both continuous mechanical compression and vascular changes in the spinal cord.

Sagittal balance of the cervical spine

Article

Full-text available

Sep 2021

The treatment of adult cervical deformity continues to be complex with high complication rates. However there are many new advancements and overall patients do well following surgical correction. To date there are now many types of cervical deformity that have been classified and there exists a variety of surgical options. These recent advances have been developed in the last few years and the field continues to grow at a rapid rate. Thus, the goal of this article is to provide an updated review of cervical sagittal balance including; cervical alignment parameters, deformity classification, clinical evaluation, with both conservative and surgical treatment options.

Alignment, Classification, Clinical Evaluation, and Surgical Treatment for Adult Cervical Deformity: A Complete Guide

Article

Feb 2021
NEUROSURGERY

Adult cervical deformity management is complex and is a growing field with many recent advancements. The cervical spine functions to maintain the position of the head and plays a pivotal role in influencing subjacent global spinal alignment and pelvic tilt as compensatory changes occur to maintain horizontal gaze. There are various types of cervical deformity and a variety of surgical options available. The major advancements in the management of cervical deformity have only been around for a few years and continue to evolve. Therefore, the goal of this article is to provide a comprehensive review of cervical alignment parameters, deformity classification, clinical evaluation, and surgical treatment of adult cervical deformity. The information presented here may be used as a guide for proper preoperative evaluation and surgical treatment in the adult cervical deformity patient.

Impact of global spine balance and cervical regional alignment on determination of postoperative cervical alignment after laminoplasty

Article

Full-text available

Nov 2018

The aim of this study is to analyze the combined impact of preoperative T1 slope (T1S) and C2-C7 sagittal vertical axis (C2-C7 SVA) on determination of cervical alignment after laminoplasty. Forty patients undergoing laminoplasty for cervical spondylotic myelopathy (CSM) with more than 2 years follow-up were enrolled. Three parameters, including cervical lordosis, T1S, and C2-C7 SVA, were measured by preoperative and postoperative radiographs. Receiver operating characteristics (ROC) curve analysis was used to determine the optimal cut-off values of preoperative T1S and C2-C7 SVA for predicting postoperative loss of cervical lordosis. Patients were classified into 4 categories based on cut-off values of preoperative T1S and C2-C7 SVA. The primary outcome was postoperative C2-C7 SVA. Change in radiographic parameters between 4 groups were compared and analyzed. Optimal cut-off values for predicting loss of cervical lordosis were T1S of 20 degrees and C2-C7 SVA of 22 mm. Patients with small C2-C7 SVA, no matter what the value of T1S, got slight loss of cervical lordosis and increase in C2-C7 SVA. Patients with low T1S and large SVA (T1 ≤20° and SVA >22 mm) got postoperative correction of kyphosis and decrease of C2-C7 SVA. However, patients with high T1S and large SVA (T1 >20° and SVA >22 mm) got mean postoperative C2-C7 SVA value of 37.06 mm, close to the threshold value of 40 mm. Determination of cervical alignment after laminoplasty relies on the equilibrium between destruction of cervical structure, kyphotic force, and adaptive compensation of whole spine, lordotic force. Lower T1S means bigger compensatory ability to adjust different severity of cervical sagittal malalignment, and vice versa.

Comparing Combined Anterior and Posterior to Posterior-Only Decompression and Fusion Crossing the Cervico-Thoracic Junction in Octogenarians

Article

Full-text available

Mar 2021

Study Design Retrospective cohort study. Objective The purpose of the study was to compare early complication, morbidity and mortality risks associated with fusion surgery crossing the cervico-thoracic junction in patients aged over 80 years undergoing combined anterior and posterior approach versus a posterior-only approach. Methods We retrospectively identified octogenarian patients with myelopathy who underwent fusion crossing the cervico-thoracic junction. Patient demographics, Nurick score, surgical characteristics, complications, hospital course, early outcome and 90-day mortality were collected. Comorbidities were classified using the age-adjusted Charlson Comorbidity Index (AACCI). Radiographic measurements for deformity correction included the C2-C7 sagittal Cobb angle, C2-7 sagittal vertical axis and T1 slope pre- and postoperatively. Results Out of 8,521 surgically treated patients, 12 octogenarian patients had a combined anterior and posterior approach (AP group) and 14 were treated from posterior-only (P group). Mean age was 81.4 ± 1.2 and 82.5 ± 2.7 years, respectively. There was no significant difference in Nurick scores between the groups ( P > 0.05). The major complication risk in the AP group was significantly higher, requiring PEG tube placement due to severe dysphagia in 4 patients (33%) compared to none in the P group. A greater improvement in cervical lordosis could be achieved through a combined approach. The 90-day mortality risk was 8% for the AP group and 0% for the P group. Conclusions A combined anterior and posterior approach is associated with a significantly higher major complication rate and can result in severe dysphagia requiring PEG tube placement in one-third of patients over 80 years of age.

Radiological outcomes following hyperlordotic cage insertion in anterior cervical discectomy and fusion

Article

Dec 2019

Background: Cervical alignment is associated with myelopathy and quality of life. Anterior cervical discectomy and fusion (ACDF) aims to decompress neural structures and optimise cervical alignment. This study examines the quantitative impact of the hyperlordotic 15° ACDF cage on cervical alignment, and compares it to that of the standard lordosis cage. Methods: A retrospective analysis of radiographical parameters of cervical alignment was conducted in 80 consecutive ACDF patients from two institutions between 2013 and 2017. Forty received 15° cages, 40 received standard cages. Pre- and post-operative Cobb angles and sagittal vertical axes (SVA) were generated from radiographical imaging utilising the SurgimapTM program. Changes in lordosis and SVA were compared within and between groups, and the significance of the change evaluated using the Student t-test. Results: In both groups, post-operative device level, segmental, and global Cobb angles were superior to preoperative values (P<0.05), especially among patients with preoperative kyphosis (P<0.05). Trends suggested greater changes in lordosis in the 15° group, but they did not reach statistical significance (P=0.06-0.23). However, subgroup analyses indicated greater device level Cobb angle change in patients less than 65 yo (P=0.049), and those with preoperative lordosis (P=0.003). Neither standard nor hyperlordotic cages significantly improved SVA in this study. Conclusions: Hyperlordotic and standard cages both improve cervical lordosis segmentally and globally. Hyperlordotic cages were not shown to be statistically superior to standard cages in this study. Prospective studies featuring consistent imaging modalities are necessary to further delineate their utility.

Morphology of the Cervical Spine Alignment in Scheuermann’s Disease

Article

Feb 2019

Piotr Janusz

Defining Cervical Sagittal Plane Deformity – When Are Sagittal Realignment Procedures Necessary in Patients Presenting Primarily With Radiculopathy or Myelopathy?

Article

Full-text available

Dec 2022

Objective: It remains unclear whether cervical sagittal deformity (CSD) should be defined by radiographic parameters alone versus both clinical and radiographic factors, and whether radiographic malalignment by itself warrants a CSD corrective surgery in patients who present primarily with neurologic symptoms. Methods: We administered a survey to a group of expert surgeons to evaluate whether radiographic parameters alone were sufficient to diagnose CSD, and in which scenarios surgeons recommend a CSD realignment procedure versus addressing the neurologic symptoms alone. Results: No single radiographic criteria reached a 50% threshold as being sufficient to establish the diagnosis of CSD. When asymptomatic radiographic malalignment was present, a sagittal deformity correction was more likely to be recommended in patients with myelopathy versus those with radiculopathy alone. The majority of surgeons recommended deformity correction when symptoms of cervical deformity were present in addition to radiographic malalignment (85% with deformity symptoms and radiculopathy, 93% with deformity symptoms and myelopathy). Conclusion: There is no consensus on which radiographic and/or clinical criteria are necessary to define the presence of CSD. We recommend that symptoms of cervical deformity, in addition to radiographic parameters, be considered when deciding whether to perform deformity correction in patients who present primarily with myelopathy or radiculopathy.

Operative treatment outcomes for adult cervical deformity: a prospective multicenter assessment with mean 3-year follow-up

Article

Jul 2022
J NEUROSURG-SPINE

Objective: Adult cervical deformity (ACD) has high complication rates due to surgical complexity and patient frailty. Very few studies have focused on longer-term outcomes of operative ACD treatment. The objective of this study was to assess minimum 2-year outcomes and complications of ACD surgery. Methods: A multicenter, prospective observational study was performed at 13 centers across the United States to evaluate surgical outcomes for ACD. Demographics, complications, radiographic parameters, and patient-reported outcome measures (PROMs; Neck Disability Index, modified Japanese Orthopaedic Association, EuroQol-5D [EQ-5D], and numeric rating scale [NRS] for neck and back pain) were evaluated, and analyses focused on patients with ≥ 2-year follow-up. Results: Of 169 patients with ACD who were eligible for the study, 102 (60.4%) had a minimum 2-year follow-up (mean 3.4 years, range 2-8.1 years). The mean age at surgery was 62 years (SD 11 years). Surgical approaches included anterior-only (22.8%), posterior-only (39.6%), and combined (37.6%). PROMs significantly improved from baseline to last follow-up, including Neck Disability Index (from 47.3 to 33.0) and modified Japanese Orthopaedic Association score (from 12.0 to 12.8; for patients with baseline score ≤ 14), neck pain NRS (from 6.8 to 3.8), back pain NRS (from 5.5 to 4.8), EQ-5D score (from 0.74 to 0.78), and EQ-5D visual analog scale score (from 59.5 to 66.6) (all p ≤ 0.04). More than half of the patients (n = 58, 56.9%) had at least one complication, with the most common complications including dysphagia, distal junctional kyphosis, instrumentation failure, and cardiopulmonary events. The patients who did not achieve 2-year follow-up (n = 67) were similar to study patients based on baseline demographics, comorbidities, and PROMs. Over the course of follow-up, 23 of the total 169 enrolled patients were reported to have died. Notably, these represent all-cause mortalities during the course of follow-up. Conclusions: This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of health-related quality of life at a mean 3.4-year follow-up, despite high complication rates and a high rate of all-cause mortality that is reflective of the overall frailty of this patient population. To the authors' knowledge, this study represents the largest and most comprehensive prospective effort to date designed to assess the intermediate-term outcomes and complications of operative treatment for ACD.

Analysis of Associating Radiologic Parameters With Clinical Outcomes After Posterior C1–2 Fusion

Article

May 2022

Objective: To evaluate which radiologic parameters affect clinical outcomes in patients underwent posterior C1-C2 fusion for atlantoaxial dislocation. Methods: From January 2014 to December 2017, among 98 patients underwent C1-C2 posterior fusion, patients with previous cervical surgery or extending to subaxial spine or basilar invagination were excluded. Finally, 38 patients were included. O-C2, C1-2, C1-C7, C2-C7 cobb angle (CA), T1 slope, C1-C7, C2-C7 sagittal vertical axis (SVA), and posterior atlantodental interval (PADI) were measured at preoperative and postoperative one year. The difference between postoperative and preoperative values for each parameter was designated as Δvalue. Postoperative subaxial kyphosis (PSK) was defined to decrease ≥10° at subaxial spine. VAS, JOA score, NDI were used to evaluate clinical outcomes. Results: Mean age was 54.4±15.9. Male to female was 14 to 24. Of radiologic parameters, C1-C7 SVA and PADI were significantly changed from 26.4±12.9mm, 17.1±3.3mm to 22.6±13.0mm, 21.6±3.4mm. △C1-C2 CA was correlated with △C1-7 CA and △C2-7 SVA. ΔPADI correlates with ΔO-C2 CA. VAS correlates with △C1-C7 CA (P = 0.03). JOA score also correlates with △C2-C7 SVA (P = 0.02). NDI was associated with ΔPADI (P < 0.01). The incidence of PSK was 23.7%, and not significant with clinical outcomes. Conclusion: △C1-C2 CA was correlated with ΔC1-C7 CA, ΔC2-C7 SVA. ΔC1-C7 CA, ΔC2-C7 SVA, and ΔPADI were the key radiologic parameters to influence clinical outcomes. Postoperative C1-C2 angle should be carefully determined as a factor affecting clinical outcomes and cervical sagittal alignment.

Deep Learning Algorithm to Evaluate Cervical Spondylotic Myelopathy Using Lateral Cervical Spine Radiograph

Article

Full-text available

Apr 2022
BMC NEUROL

Background Deep learning (DL) is an advanced machine learning approach used in different areas such as image analysis, bioinformatics, and natural language processing. A convolutional neural network (CNN) is a representative DL model that is highly advantageous for imaging recognition and classification This study aimed to develop a CNN using lateral cervical spine radiograph to detect cervical spondylotic myelopathy (CSM). Methods We retrospectively recruited 207 patients who visited the spine center of a university hospital. Of them, 96 had CSM (CSM patients) while 111 did not have CSM (non-CSM patients). CNN algorithm was used to detect cervical spondylotic myelopathy. Of the included patients, 70% (145 images) were assigned randomly to the training set, while the remaining 30% (62 images) to the test set to measure the model performance. Results The accuracy of detecting CSM was 87.1%, and the area under the curve was 0.864 (95% CI, 0.780-0.949). Conclusion The CNN model using the lateral cervical spine radiographs of each patient could be helpful in the diagnosis of CSM.

Association between pre-operative sagittal alignment and radiographic measures of decompression following cervical laminectomy: a retrospective cohort study

Article

Full-text available

Sep 2021

Background: The primary purpose of this study was to determine the association between pre-operative cervical sagittal alignment and the extent of cord decompression in the form of increased spinal cord width and cerebrospinal fluid (CSF) space in front of and behind the cord in patients undergoing laminectomy for cervical spondylotic myelopathy (CSM). Secondary objectives included an assessment of the correlation between increasing numbers of levels decompressed and the post-operative cervical spine sagittal alignment, the effect of laminectomy on the change in alignment, as well as effect of laminectomy on pre-existing spinal cord signal abnormality. Methods: This retrospective cohort study included patients who underwent cervical laminectomies, without fusion, between 2015 and 2020. Chart review was used to collect baseline variables. Cervical sagittal alignment, width of the spinal cord, and the CSF space in-front and behind the cord was measured pre-operatively and post-operatively using magnetic resonance imaging (MRI) scans for each patient. The correlation between change in measured parameters and pre-operative cervical sagittal alignment was assessed using Spearman's correlation. Results: Thirty-five patients were included. Average age was 65.29±10.98 years old. The majority of patients (80%) underwent laminectomies at 3-4 levels. Average pre-operative sagittal alignment determined by the Cobb angle was 6.05°±14.17°, while the average post-operative Cobb angle was 3.15°±16.64°. The change in Cobb angle was not statistically significant (P=0.998). Eleven patients (32%) had pre-operative kyphotic sagittal alignment. The average time from surgery to post-operative MRI scan was 20.44±13.18 months (range, 3-39; median, 18.5; IQR, 23.5). There was no statistically significant association between increasing levels of decompression and change in alignment (P=0.546). Cord signal abnormality persisted after decompression. There was a moderate correlation between lordotic pre-operative cervical sagittal alignment and change in space in-front of the cord (correlation coefficient 0.337, P=0.048) and change in cord width (correlation coefficient 0.388, P=0.021). Conclusions: Severity of pre-operative kyphotic sagittal alignment is associated with decreased spinal cord drift and extent of decompression. The pre-operative sagittal alignment is not significantly associated with the change in post-operative alignment. Increasing number of levels decompressed does not worsen a kyphotic cervical spine sagittal alignment.

Factors associated with postoperative axial symptom after expansive open-door laminoplasty: retrospective study using multivariable analysis

Article

Full-text available

Nov 2020
EUR SPINE J

PurposeThe aim of the present study was to investigate the factors associated with axial symptom using multivariable analysis.Methods The authors retrospectively assessed 249 patients treated by open-door laminoplasty. The patients were classified into two groups: axial symptom and no axial symptom group. The possible factors included demographic variables (age, sex, BMI, smoking, heart disease, diabetes, preoperative neck pain, preoperative JOA scores, preoperative NDI, course of disease and pathogenesis) and surgical and radiological variables [operation time, intraoperative blood loss, collar wear time, preoperative cervical curvature, postoperative cervical curvature, T1 slope, preoperative and postoperative C2 sagittal vertical axis (C2 SVA)].ResultsThe prevalence of axial symptom was 34.9% (89/249). The collar wear time, preoperative and postoperative C2 SVA were risk factors for axial symptom. A cutoff value of 22.6 mm for preoperative C2 SVA and 3.5 weeks for collar wear time predicted the development of axial symptom.Conclusions The longer collar wear time, larger preoperative and postoperative C2 SVA were positively correlated with the higher incidence of axial symptom.

Trends in Posterior Cervical Fusion for Deformity in the United States from 2000 to 2017

Article

Full-text available

Jun 2020

BACKGROUND Posterior cervical decompression and fusion (PCF) is a common treatment for cervical spondylotic myelopathy. Treatment paradigms are shifting from simple decompression and fusion to correcting cervical deformities. OBJECTIVE To identify trends in PCF with an emphasis on cervical deformity and surgical complexity. METHODS Adults who underwent PCF from 2000 to 2017 were retrospectively identified in the Premier Healthcare Database (PHD) using International Classification of Disease Codes (ICD) 9 and 10. Patients were dichotomized into those with or without deformity diagnosis. PCF complexity was defined by adjunct surgical codes, including anterior cervical fusion, extension to thoracic levels, and osteotomy. Patient characteristics, including demographics, functional comorbidity index (FCI), and hospital characteristics, were extracted and annual procedures were projected to the US population. RESULTS A total of 68 415 discharges for PCF were identified. Compound annual growth rate (CAGR) of PCF from 2000 to 2017 for nondeformity cases was 9.7% and 16.5% for deformity. The demographics with the greatest growth were deformity patients aged 65 to 74 yr (15.1%). The CAGR of anterior cervical fusion and extension to thoracic levels was higher for deformity patients compared to nondeformity patients, 13.6% versus 3.9% and 20.4% versus 16.6%, respectively. CONCLUSION Rates of PCF for deformity are increasing at a greater rate than nondeformity PCF. The most growth was seen among deformity patients aged 65 to 74 yr. Surgical complexity is also changing with increasing use of anterior cervical fusion and extension of PCF to include thoracic levels.

The Effect of Head Loading on Cervical Spine in Manual Laborers

Article

Full-text available

Mar 2020

Study design: A prospective case-control study. Purpose: To determine the effect of axial loading on the cervical spine when weights are carried on the head. Overview of literature: Traditionally, carrying weights on the head has been a common practice in developing countries. The laborers working in agriculture, construction, and other industries, as well as porters at railway platforms, are required to lift heavy weights. Since controversy exists regarding carrying weights on the head, we decided to evaluate its effect on the cervical spine. Methods: The study comprised 62 subjects. Of this number, 32 subjects (group A) were unskilled laborers from the construction industry; the other 30 subjects (group B) were in the control group and had never previously carried heavy weights on their heads. Cervical spine radiographs were taken for all the 62 subjects. Subjects in group A were asked to carry a load (approximately 35 kg) on their heads and walk for about 65 m, with their cervical spine radiographs taken afterward. Results: The mean ages of patients in groups A and B were 27.17 and 25.75 years, respectively. The mean cervical lordosis observed in group A (18.96°) was dramatically less compared with group B (25.40°), showing a further decrease in head loading (3.35°). Five subjects had a reversal of lordosis (-5.61°). A statistically significant reduction in disc height and listhesis was observed when the load was carried on the head with a further decrease after walking with the load. Accelerated degenerative changes, particularly affecting the upper cervical spine, were observed in head loaders. Conclusions: Carrying a load on the head leads to accelerated degenerative changes, which involve the upper cervical spine more than the lower cervical spine and predisposes it to injury at a lower threshold. Thus, alternative methods of carrying loads should be proposed.

Imaging in myelopathy, Symposium – Cervical Spondylo-myelopathy. Indian Spine journal, Year : 2019 | Volume : 2 | Issue : 1 | Page : 20-32. DOI: 10.4103/isj.isj_63_18.

Article

Feb 2020

Sri Vijay Anand K S

The Sagittal Balance of the Cervical Spine: Radiographic Analysis of Interdependence between the Occipitocervical and Spinopelvic Alignment

Article

Full-text available

Jan 2020

Study design: This was a prospective clinical study. Purpose: Previous studies have indicated that cervical lordosis is a parameter influenced by segmental and global spinal sagittal balance parameters. However, this correlation still remains unclear. Therefore, a better understanding of the normal values and interdependencies between inter-segmental alignment parameters is needed. This is a preliminary analysis that helps to understand these factors. Overview of literature: Change in global sagittal alignment is associated with poor health-related quality of life. Questions regarding which parameters play the primary roles in the progression of spinal sagittal imbalance and which might be compensatory factors remain unanswered. Methods: Prospectively, 420 adults (105 asymptomatic, 105 cervical symptomatic, 105 lumbar symptomatic, and 105 post-surgical) were selected. Whole-spine standing lateral radiographs were taken, and spinopelvic, thoracic, and cervical parameters were measured. Then, the data were analyzed using correlation coefficient test and multiple regression analysis. Results: All the parameters showed a normal distribution. The mean values of the cervical parameters are as follows: C1C2 Cobb angle, -27.07°±4.3°; C2C7 Cobb angle, -16.4°±5.6°; OCC2 Cobb angle, -14.5°±3.8°; OCC7 Cobb angle, -29.8°±5.6°; C2C7 Harrison angle, 20.4°±4.3°; and C7 slope, -25.4°±5.6°. The analysis of these parameters revealed no statistically significant difference between asymptomatic, symptomatic, and post-surgical patients. C7 sagittal vertical axis (SVA) correlated with the C2C7 Cobb angle (r =0.7) in all groups. No significant correlation was noted between cervical and spinopelvic parameters in asymptomatic patients. However, C1C2 Cobb angle correlated significantly with pelvic incidence (PI, r =-0.2), lumbar lordosis (LL, r =0.2), and pelvic tilt (PT, r =-0.2) in cervical symptomatic patients. Irrespective of the patient symptom sub-group (n=420), C1C2 Cobb angle correlated with LL (r =0.1) and C2C7 Harrison angle correlated with PI and PT (r =0.1). Conclusions: Our results indicate significant interdependence between the spinopelvic and cervical alignment, especially in cervical symptomatic patients. In addition, strong correlation was found between the C7 SVA and C2C7 Cobb angle. Overall, the results of this study could help to better understand the cervical sagittal alignment and serve as preliminary data for planning surgical reconstruction procedures.

Creation of a Porcine Kyphotic Model

Article

Mar 2019

Study design: Large animal study. Objective: Create a thoracic hyperkyphotic deformity in an immature porcine spine, so that future researchers may use this model to validate spinal instrumentation and other therapies used in the treatment of hyperkyphosis. Summary of background data: Although several scoliotic animal models have been developed, there have been no reports of a thoracic hyperkyphotic animal model creation in an immature animal. The present study was designed to produce a porcine hyperkyphotic model by the time the pig weighed 25 kg, which corresponds to the approximate weight of a child undergoing surgery for early-onset scoliosis (EOS). Methods: Successful surgical procedures were performed in 6 consecutive 10-kg (male, 5-week-old) immature Yorkshire pigs. Procedure protocol consisted of 1) a left thoracotomy at T10-T11, 2) screw placement at T9 and T11, 3) partial vertebrectomy at T10, 4) posterior interspinous ligament transection, and 5) placement of wire loop around screws and tightening. Weekly x-ray imaging was performed preoperatively and postoperatively, documenting progressively increasing kyphosis as the pig grew. Necropsy was performed 5-6 weeks after surgery, with CT, slab section, and histologic analysis. Results: Average T9-T11 kyphosis (measured by sagittal Cobb angle) was 6.1° ± 1.4° (mean ± SD) preoperatively, 30.5° ± 1.0° immediately postoperation, and significantly increased to 50.3° ± 7.2° (p < .0001) over 5-6 weeks in 6 consecutive pigs at time of necropsy. Conclusions: An animal model of relatively more rigid-appearing thoracic hyperkyphotic deformities in immature pigs has been created. Subsequent studies addressing management of early-onset kyphosis with spinal instrumentation are now possible. Level of evidence: Level V.

Vertebral Çökme Kırıklarında Vertebral Korpusu Çökme Derecesinin Radyolojik ve Biyokimyasal Ölçüm Parametreleri ile Değerlendirilmesi

Article

Full-text available

Dec 2019
J Harran Unv Med F

Amaç: Bu çalışmanın amacı, retrospektif olarak çökme kırığı olan hastaların başlangıç ile altıncı ay takiplerindeki radyolojik bulgularını ve kan biyokimyasal değerlerini analiz etmektir. Materyal ve Metod: Haziran 2014 ile Aralık 2018 tarihleri arasında takipli 70torakolomber çökme kırık olgusu retrospektif olarak değerlendirildi. Herhangi bir yaş ve cinsiyet ayrımı yapılmayıp, sadece multipl çökme kırıkları, enfeksiyonlar ve metastazlar çalışma dışında bırakıldı. Radyolojik ve biyokimyasal veriler retrospektif olarak kayıt edildi. İstatistiksel olarak analiz edildi. Bulgular: 70 torakolomber omurga çökme kırık olgusu retrospektif olarak değerlendirildiğinde vakaların 41’i (53,68±19,27) erkek, 29’ı (61,1±16,87) kadındı. Ortalama yaş 56,76±18,56 (14-98) idi. Erkek ve kadınlar arasında erkeklerin sayısı fazla olmakla birlikte, istatistiksel açıdan karşılaştırdığımızda anlamlılık bulunmadı (p=0,09). İleri yaşlarda ise kadınlarda sık görülmekteydi. Torakolomber çökme kırıkları sıklıkla T11-L2 düzeyinde görüldü. Vakaların başlangıç kifoz açıları (10,56±6,97) ile altıncı ay kifoz açıları (12,25±7,47) karşılaştırıldığında, istatistiksel açıdan anlamlı bulundu (p<0.001). Biyokimyasal değerler kendi aralarında pozitif yönde korele iken, yaş ile albumin değerlerinin negatif yönde korele olduğu görüldü. Kifoz açısı ile yaş, biyokimyasal değerler arasında anlamlı korelasyon görülmedi. Sonuç: Çalışmamızda torakolomber omurga çökme kırıklarında zamanla kifoz açısının arttığını gördük. Bu durum yaş ve kan biyokimyasal değerlerinden total protein, albumin, kalsiyum ile ilişkili olmadığı görüldü. Anahtar kelimeler: Çökme kırığı, Kifoz açısı, Omurga

Sagittal Reconstruction and Clinical Outcome Using Traditional ACDF, Versus Stand-alone ACDF Versus TDR: A Systematic Review and Quantitative Analysis

Article

Jun 2019

MINI: Though Neck Disability Index (NDI) scores improved across devices for anterior cervical discectomy and fusion (ACDF) using a structural graft and plate, a stand-alone device, or a total disc arthroplasty (TDR), there was no significant difference in NDI improvement or C2-7 Cobb angle change between single level traditional ACDF, stand-alone ACDF, or TDR. TDR has not been considered a lordosis producing operation; however, our investigation shows it does not differ significantly in sagittal profile from other cervical fusion techniques. Study design: Systematic review. Objective: To determine the difference in postoperative sagittal alignment when single level cervical radiculopathy or myelopathy is treated with an anterior cervical discectomy and fusion (ACDF) using a structural graft and plate, a stand-alone ACDF, or a total disc arthroplasty (TDR). We also wanted to determine if postoperative sagittal alignment impacted clinical outcomes in this patient population. Summary of background data: Although there are several accepted techniques for interbody reconstruction during single level anterior cervical surgery, little is known on the impact of any of them on segmental and regional sagittal alignment. Methods: A systematic review of the literature was performed according to the PRISMA guidelines of the PubMed, Embase, and Cochrane databases. Only studies which contained pre and postoperative C2-7 Cobb angles as well as Neck Disability Index (NDI) scores following single level traditional ACDF with plate and cage, stand-alone ACDF, or TDR with at least 1 year follow up were included. Results: There were 12 publications that fulfilled the inclusion criteria with a total of 658 patients. Cluster regression analysis showed no difference between treatment arms at each respective time-point or in the overall change in NDI from preoperative to postoperative (P = 0.88). Cluster regression analysis showed no difference between treatment arms at each respective time point or in the overall change in lordosis from pre-op to post-op (P = 0.93). Conclusion: This review provides evidence that while NDI scores improved across all devices, there was no significant difference in NDI improvement or C2-7 Cobb angle change between single level traditional ACDF, stand-alone ACDF, or TDR. Although TDR has not been considered a lordosis producing operation, our investigation shows it does not differ significantly in sagittal profile from other cervical fusion techniques. Moreover, we show that the NDI score improved, regardless of device implanted. Level of evidence: 1.

Implications of Subarchnoid Block in Senile Kyphosis

Article

Full-text available

Dec 2018

Since the literature related to safety or efficacy of placing spinal blocks in patients with kyphosis is lacking, we aim to discuss about the anaesthesia implications of spinal anaesthesia in senile kyphosis. We successfully administered spinal anesthesia in three elderly patients with predominant kyphotic deformity with absent or mild scoliosis. The needle insertion attempts did not exceed two and a smaller dose of anesthetic was sufficient. While choosing spinal anaesthesia in patients with kyphosis, a risk benefit analysis needs to be performed based on the co-presence of scoliosis and its severity, desired level of anesthesia, and associated or coexisting systemic illness.

Imaging in cervical myelopathy

Article

Jan 2019

This is a narrative review. The objective of this study is to provide an overview on the imaging modalities and their utilization in cervical myelopathy (CM). Using PubMed, studies published on the “imaging modalities in CM,” “cervical spondylotic myelopathy (CSM) imaging,” “computed tomography (CT) and magnetic resonance imaging (MRI) in CM,” “imaging in ossified posterior longitudinal ligament (OPLL),” “dural ossification in OPLL,” “diffusion tensor imaging (DTI) in CSM,” and “dynamic MRI, functional MRI, and magnetic resonance spectroscopy (MRS) in CSM” were evaluated. The review addresses the evaluation of CM with various imaging modalities ranging from radiographs, CT, and MRI to advanced imaging techniques such as DTI and MRS. Each investigation contributes specific detail to the disease process in a different dimension. Specific parameters for CSM and OPLL, and their influence on outcome are discussed. Imaging in CM plays an important role in analyzing the cause of myelopathy, defining the level of the lesion, parameters to assess the time of intervention and to predict the outcome.

Characteristics of deformity surgery in patients with severe and rigid cervical kyphosis (CK): results of the CSRS-Europe multi-centre study project

Article

Full-text available

Feb 2019
EUR SPINE J

Introduction and purpose Little information exists on surgical characteristics, complications and outcomes with corrective surgery for rigid cervical kyphosis (CK). To collate the experience of international experts, the CSRS-Europe initiated an international multi-centre retrospective study. Methods Included were patients at all ages with rigid CK. Surgical and patient specific characteristics, complications and outcomes were studied. Radiographic assessment included global and regional sagittal parameters. Cervical sagittal balance was stratified according to the CSRS-Europe classification of sagittal cervical balance (types A–D). Results Eighty-eight patients with average age of 58 years were included. CK etiology was ankylosing spondlitis (n = 34), iatrogenic (n = 25), degenerative (n = 9), syndromatic (n = 6), neuromuscular (n = 4), traumatic (n = 5), and RA (n = 5). Blood loss averaged 957 ml and the osteotomy grade 4.CK-correction and blood loss increased with osteotomy grade (r = 0.4/0.6, p < .01). Patients with different preop sagittal balance types had different approaches, preop deformity parameters and postop alignment changes (e.g. C7-slope, C2–7 SVA, translation). Correction of the regional kyphosis angle (RKA) was average 34° (p < .01). CK-correction was increased in patients with osteoporosis and osteoporotic vertebrae (POV, p = .006). 22% of patients experienced a major long-term complication and 14% needed revision surgery. Patients with complications had larger preop RKA (p = .01), RKA-change (p = .005), and postop increase in distal junctional kyphosis angle (p = .02). The POV-Group more often experienced postop complications (p < .0001) and revision surgery (p = .02). Patients with revision surgery had a larger RKA-change (p = .003) and postop translation (p = .04). 21% of patients had a postop segmental motor deficit and the risk was elevated in the POV-Group (p = .001). Conclusions Preop patient specific, radiographic and surgical variables had a significant bearing on alignment changes, outcomes and complication occurrence in the treatment of rigid CK. Graphical abstract Open image in new window

Two-stage corrective surgery for severe rigid cervical kyphotic deformity with unilateral vertebral artery occlusion after old blunt trauma: a case report

Article

Dec 2018

Introduction: There are considerable risks for vertebral artery (VA) injury in case of corrective surgery for a severe and rigid cervical kyphotic deformity. This case report describes a rare case of surgical management for pre-existing traumatic rigid cervical kyphosis associated with unilateral VA occlusion. Case presentation: A 73-year-old male fell down and injured his neck. He was referred to our hospital 10 months after injury because his degree of head drop progressed gradually to a chin-on-chest position such that he could not look straight forward. On plain X-ray, the C2-7 angles in the neutral, flexion, and extension positions were 61°, 71°, and 50°, respectively. CT revealed a collapse of the C5 vertebral body and bone fusion between C4 and C5 in the anterior vertebrae, and unilateral VA occlusion was confirmed by angiography. Two-stage surgery was planned to correct the kyphosis. In the first stage, anterior release of the C4/5 bone-spur fusion and dissection of the intervertebral disk were performed. After release, angiography confirmed neither occlusion nor rupture of the VA. In the second stage, anterior and posterior fixation was performed at correcting position while maintaining slight kyphosis in order to avoid excessive distortion of the VA. The postoperative C2-7 kyphosis angle improved to 16° without any VA injury, and the patient could look forward easily. Discussion: The degree of correction as well as risk management of VAs should be considered carefully during corrective surgery for severe and rigid cervical kyphosis, especially with unilateral VA occlusion.

A rare cause of late onset neurological deficit in post tuberculous kyphotic deformity—case report

Article

Dec 2017

Late onset neurological deficit is a rare complication of spinal tuberculosis. Reactivation of the disease and compression by internal gibbus are the common causes for late onset neurological deficit. We report a rare cause of late onset paraplegia in a patient with post tubercular kyphotic deformity. The late onset neurological deficit was due to the adjacent segment degeneration proximal to the kyphotic deformity. Posterior hypertrophied ligamentum flavum and anterior disc osteophyte complex caused the cord compression. The increased stress for prolonged period at the end of the deformity was the reason for the accelerated degeneration. Patient underwent posterior decompression, posterolateral and interbody fusion. Deformity correction was not done. To our best knowledge, this is only the second report of this unusual cause of late onset paraplegia.

Changes in T1 slope and cervical sagittal vertical axis correlate to improved neurological function recovery after cervical laminoplasty

Article

Full-text available

Sep 2022

Purpose: To investigate the influence of changes in T1 slope (T1S) and cervical sagittal vertical axis (CSVA) on cervical laminoplasty outcomes. Methods: Eighty-one patients with cervical spondylotic myelopathy (CSM) treated with cervical laminoplasty were enrolled in this study. Demographic parameters included age and follow-up time. Imaging data included occiput-C2 lordosis (OC2), C2-C7 Cobb angle (CL), T1S, CSVA. Outcome assessment indicators included the Japanese Orthopedic Association (JOA) score, JOA recovery rate, and neck disability index (NDI). All patients were grouped based on preoperative T1S and variation in CL after surgery, respectively. Patients with decreased CL postoperatively were further grouped according to whether they were combined with T1S reduction. Results: There were no significant differences in the final JOA score, JOA recovery rate, or NDI between patients with different T1S. Patients with loss of CL postoperatively had lower JOA score and JOA recovery rate, but higher NDI than patients with sustained CL. Furthermore, patients with CL loss but compensate for it with reduction in T1S had lower CSVA, higher JOA score and JOA recovery rate than those with CL loss alone. Conclusions: Decreased T1S postoperatively prevents the tendency of the cervical spine to tilt forward by regulating CSVA and facilitates recovery of neurological function after cervical laminoplasty.

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

Article

Apr 2022
J BIOMED NANOTECHNOL

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 (C 0–2 Coob, C 2–7 Coob, 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 (C 0–2 Cobb, C 2–7 Cobb, T1S, CSVA, and TIA), we observed no significant difference between these two groups before and after the operation. In addition, we showed that C 0–2 Cobb and C 2–7 Cobb angle had a significant positive correlation; and C 0–2 Cobb 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.

Finger trembling improvement after surgery in Hirayama disease: a case report

Article

Apr 2022

Introduction: Finger trembling is a characteristic physical finding in Hirayama disease. Although conservative treatment is recommended to stop disease progression, surgery is optional in some cases. However, the postoperative recovery of finger trembling is scarcely reported. Case presentation: A 26-year-old Japanese female patient whose chief complaint was left finger trembling with active finger extension presented at our hospital. Hand weakness without muscle atrophy of the left arm was observed. MRI showed left-side oriented intramedullary signal change with concomitant cord atrophy at C4-5 and C5-6. The CT myelogram (CTM) on flexion showed anterior cord compression and anterior shift of posterior dura matter from C4 to C6. And CTM on extension showed the resolution of both findings. Electrophysiological studies showed active and chronic neuronal damage and preserved motor neuron pool of hand muscle. Since she had exhibited a gradual aggravation of symptoms over a period of 5 years, she underwent anterior cervical discectomy and fusion after careful assessment of both conservative and surgical treatment. Finger trembling recovered soon after surgery. Discussion: Finger trembling is an unfamiliar physical finding in terms of postoperative recovery prediction. Anterior horn cell impairment is postulated as a cause of finger trembling. Postural restoration of spinal cord shape and cerebrospinal fluid around the cord with preserved neural function could facilitate functional recovery.

Commentary: Case Report of Angular Post-Tuberculotic Kyphosis Corrected Through Pedicle Subtraction Osteotomy Above C7

Article

Dec 2021

Postoperative Cervicothoracic Kyphosis Following Infantile Intramedullary Tumor Resection Accelerates Neurological Deterioration

Article

Full-text available

Oct 2021

Intramedullary spinal cord tumors are rare in children. Regardless of the type of tumor, surgical removal is thought to improve progression-free survival. However, postoperative kyphosis is a serious problem in children, who can expect long-term survival. We present a pediatric case of neurofibromatosis type 2-related spinal ependymoma at the cervicothoracic regions where acute neurological deterioration was developed due to a combination of tumor recurrence and postoperative kyphotic deformity. In the first surgery, subtotal tumor resection was performed via osteoplastic laminotomy. Postoperative radiological evaluation at several months showed cervicothoracic junctional kyphosis, which subsequently made a significant improvement by lifestyle instructions. However, 22 months after the surgery, he exhibited rapid neurological deterioration caused by the regrowth of the recurrent tumor and re-emergence of kyphotic deformity, which led to the fixed laminar flap sank into the spinal canal. Therefore, a second surgery was performed 23 months after the first surgery, and gross total removal was achieved. Osteoplastic laminotomy is presumed to reduce the occurrence of postoperative kyphosis compared with laminectomy, but there have been no reports on the spinal cord compression by plunging of the re-fixed laminar flap into the spinal canal. The kyphosis deformity increases the chance of re-fixed laminar flap coming off, thereby accelerating neurological injury on top of the neural damage by tumor recurrence itself. Therefore, pediatric patients with spinal cord tumors should be carefully managed in terms of recurrent tumors and postoperative kyphosis, and timely surgical intervention is necessary before kyphotic deformity becomes evident.

Radiological factors associated with the severity of corticospinal tract dysfunctions for cervical spondylotic myelopathy: An analysis of the central motor conduction time and kinematic CT myelography

Article

Dec 2021
J CLIN NEUROSCI

Patients with cervical spondylotic myelopathy (CSM) often exhibit symptoms in clinical practice, particularly the elderly, whose lower extremity functions are more likely to deteriorate; however, the underlying mechanisms currently remain unclear. The present study aimed to elucidate the relationship between the neurological severity of CSM based on an electrophysiological examination and radiological findings. Eighty-six patients with CSM were examined using kinematic CT myelography. The cross-sectional area of the spinal cord and dynamic changes in the spinal cord were measured at the affected level. The central motor conduction time (CMCT) using transcranial magnetic stimulation was calculated as follows: motor evoked potential latency - (compound muscle action potential latency + F latency − 1)/2 (ms). A multiple logistic regression analysis was performed to identify the radiological parameters associated with severe lower limb dysfunction. CMCT in the upper limbs correlated with spinal cord compression during neck extension, while that in the lower limbs correlated with a larger C2-7 sagittal vertical axis, cervical lordosis, a small C2-7 range of motion (ROM), and spinal cord compression during neck flexion. In a multiple logistic regression analysis, significant risk factors specific for severe lower limb dysfunction were greater anterior spondylolisthesis during neck extension (P = 0.006, OR: 2.53, 95%CI: 1.13–2.07) and small C2-7 ROM in neutral to flexion (P = 0.035, OR: 0.67, 95%CI: 0.52–0.88). Imaging findings affect upper and lower extremity functions in specific manners. Cervical stiffness or anterior compression factors may be associated with the deterioration of lower limb function.

The Frontier of Treatment for Cervical Degenerative Disorders頚椎変性疾患に対する治療のフロンティア

Article

Jan 2021

Toshitaka Seki

Currently, the gold standard for the surgical treatment of cervical degenerative diseases is anterior cervical discectomy and fusion (ACDF) and laminoplasty (or laminectomy). However, unresolved problems include adjacent segment disease after ACDF and kyphosis after laminoplasty (or laminectomy). As a recent topic for cervical degenerative diseases, the new anterior technique, which is anterior cervical disc replacement (ACDR), has become available in Japan. ACDR is a relatively new motion-preserving procedure and is expected to prevent adjacent segment disease. Although good surgical results have been reported in Western and Asian countries except for Japan, where it has been introduced in advance. The long-term results in Japan are unknown, and careful follow-up is required. Cervical laminoplasty (or laminectomy) is indicated for cases with the preoperative alignment of lordosis or mild kyphosis. Despite the maintenance of preoperative alignment, some patients have poor postoperative surgery results. Therefore, the concept of cervical spine sagittal balance was proposed, as well as the thoracolumbar spine sagittal balance. The C2-C7 sagittal vertical axis, which indicates the anterior deviation of the cervical spine ; the chin-brow to vertical angle, which is an index of horizontal vision ; the T1 Slope, which is an index of cervical lordosis ; and cervical lordosis are used as the parameters of cervical spine sagittal balance. It is becoming an index for selecting surgical procedures.

The associations between radiological and neurological findings of degenerative cervical myelopathy: radiological analysis based on kinematic CT myelography and evoked potentials of the spinal cord

Article

Jul 2021

OBJECTIVE Neurological and imaging findings play significant roles in the diagnosis of degenerative cervical myelopathy (DCM). Consistency between neurological and imaging findings is important for diagnosing DCM. The reasons why neurological findings exhibit varying sensitivity for DCM and their associations with radiological findings are unclear. This study aimed to identify associations between radiological parameters and neurological findings in DCM and elucidate the utility of concordance between imaging and neurological findings for diagnosing DCM. METHODS One hundred twenty-one patients with DCM were enrolled. The Japanese Orthopaedic Association (JOA) score, radiological parameters, MRI and kinematic CT myelography (CTM) parameters, and the affected spinal level (according to multimodal spinal cord evoked potential examinations) were assessed. Kinematic CTM was conducted with neutral positioning or at maximal extension or flexion of the cervical spine. The cross-sectional area (CSA) of the spinal cord, dynamic change in the CSA, C2–7 range of motion, and C2–7 angle were measured. The associations between radiological parameters and hyperreflexia, the Hoffmann reflex, the Babinski sign, and positional sense were analyzed via multiple logistic regression analysis. RESULTS In univariate analyses, the upper- and lower-limb JOA scores were found to be significantly associated with a positive Hoffmann reflex and a positive Babinski sign, respectively. In the multivariate analysis, a positive Hoffmann reflex was associated with a higher MRI grade (p = 0.026, OR 2.23) and a responsible level other than C6–7 (p = 0.0017, OR 0.061). A small CSA during flexion was found to be significantly associated with a positive Babinski sign (p = 0.021, OR 0.90). The presence of ossification of the posterior longitudinal ligament (p = 0.0045, OR 0.31) and a larger C2–7 angle during flexion (p = 0.01, OR 0.89) were significantly associated with abnormal great toe proprioception (GTP). CONCLUSIONS This study found that the Hoffmann reflex is associated with chronic and severe spinal cord compression but not the dynamic factors. The Babinski sign is associated with severe spinal cord compression during neck flexion. The GTP is associated with large cervical lordosis. These imaging features can help us understand the characteristics of the neurological findings.

Redefining cervical spine deformity classification through novel cutoffs: An assessment of the relationship between radiographic parameters and functional neurological outcomes

Article

Full-text available

Apr 2021
J Craniovertebr Junction Spine

Purpose: The aim is to investigate the relationship between cervical parameters and the modified Japanese Orthopedic Association scale (mJOA). Materials and methods: Surgical adult cervical deformity (CD) patients were included in this retrospective analysis. After determining data followed a parametric distribution through the Shapiro-Wilk Normality (P = 0.15, P > 0.05), Pearson correlations were run for radiographic parameters and mJOA. For significant correlations, logistic regressions were performed to determine a threshold of radiographic measures for which the correlation with mJOA scores was most significant. mJOA score of 14 and <12 reported cut-off values for moderate (M) and severe (S) disability. New modifiers were compared to an existing classification using Spearman's rho and logistic regression analyses to predict outcomes up to 2 years. Results: A total of 123 CD patients were included (60.5 years, 65%F, 29.1 kg/m2). For significant baseline factors from Pearson correlations, the following thresholds were predicted: MGS (M:-12 to-9° and 0°-19°, P = 0.020; S: >19° and <-12°, χ2= 4.291, P = 0.036), TS-CL (M: 26°to 45°, P = 0.201; S: >45°, χ2= 7.8, P = 0.005), CL (M:-21° to 3°, χ2= 8.947, P = 0.004; S: <-21°, χ2= 9.3, P = 0.009), C2-T3 (M: -35° to -25°, χ2= 5.485, P = 0.046; S: <-35°, χ2= 4.1, P = 0.041), C2 Slope (M: 33° to 49°, P = 0.122; S: >49°, χ2= 5.7, P = 0.008), and Frailty (Mild: 0.18-0.27, P = 0.129; Severe: >0.27, P = 0.002). Compared to existing Ames- International Spine Study Group classification, the novel thresholds demonstrated significant predictive value for reoperation and mortality up to 2 years. Conclusions: Collectively, these radiographic values can be utilized in refining existing classifications and developing collective understanding of severity and surgical targets in corrective surgery for adult CD.

Predictive Effect of Cervical Spinal Cord Compression and Corresponding Segmental Paravertebral Muscle Degeneration on the Severity of Symptoms in Patients with Cervical Spondylotic Myelopathy

Article

Mar 2021
SPINE J

Background Context Previous studies have found that cervical sagittal parameters and spinal cord compression are important risk factors for cervical spondylotic myelopathy (CSM). An increasing number of scholars believe that cervical muscle condition is also one of the factors affecting the severity of symptoms in affected patients. Purpose To determine whether: the degree of corresponding segmental paravertebral muscle degeneration is related to the severity of symptoms in patients with CSM; the degree of cervical spinal cord compression can predict the severity of symptoms in patients with CSM. Study Design A retrospective study. Patient Sample From January 2015 to January 2019, 121 patients with CSM were enrolled. Outcome Measures The VAS, NDI and mJOA were used to assess cervical spinal function and quality of life. Methods From January 2015 to January 2019, 121 patients with CSM were enrolled. The inclusion criterion was the presence of complete cervical lateral radiography and MRI data. The following radiographic parameters were measured: (1) C0-C2 Cobb angle; (2) C2-C7 Cobb angle (CL); (3) T1 slope (T1S); (4) neck tilt (NT); (5) C2-C7 sagittal vertical axis (SVA); and (6) T1S-CL. The following MRI parameters were measured: (1) up(low)-fat/muscle; (2) up(low)-fat/centrum; (3) up(low)-muscle/centrum; (4) cervical cord compression index (CCI); (5) S-index; and (6) cervical spinal cord compression area ratio (S0/S1). The VAS, NDI and mJOA were used to assess cervical spinal function and quality of life. The patients were divided into 2 groups according to the mJOA score: group A (mild-moderate symptom group, mJOA score≥12 points) and group B (severe symptom group, mJOA score<12 points). The Pearson correlation coefficient was used to assess the correlations between cervical sagittal parameters, MRI parameters and functional scores. Logistic regression analysis and ROC curve analysis were performed to identify independent risk factors and critical values. Results In patients with CSM, the VAS score is positively correlated with NT, up-fat/centrum, S-index and S0/S1. The NDI is positively correlated with NT, up-fat/muscle, up-fat/centrum, S-index, and S0/S1 and negatively correlated with C0-2N and CL. The mJOA score is positively correlated with CL and negatively correlated with C2-7 SVA, CCI, S-index, and S0/S1. Thus, corresponding segmental paravertebral muscle degeneration has relevance to neck pain, but it is not related to limb weakness, neurological dysfunction, gait impairment, sensation or bladder/bowel function dysfunction. Through mJOA score grouping and binary logistic regression analysis, we found that S0/S1 is the only independent risk factor for severe symptoms in patients with CSM. When S0/S1>0.295, the clinical symptoms of patients are more severe. Thus, in clinical practice, when the degree of spinal cord compression exceeds 30%, the clinical symptoms are more severe. Conclusion In patients with CSM, corresponding segmental paravertebral muscle degeneration has relevance to neck pain, but it does not relate to limb weakness, neurological dysfunction, gait impairment, sensation or bladder/bowel function dysfunction. Cervical spinal cord compression is the only independent risk factor;when the degree of spinal cord compression exceeds 30%, the clinical symptoms are more severe.

Kyphotic Neck and Correlation With Clinical Outcomes

Article

Full-text available

Jan 2016

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

Article

Full-text available

Jun 2021
EUR SPINE J

Purpose 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. Methods 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. Results 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). Conclusion 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.

Exclusion of Ossified Ligaments Behind C2 Vertebra Combined with Anterior Controllable Antedisplacement and Fusion for Cervical Ossification of the Posterior Longitudinal Ligament Extending to C2 Segment

Article

Dec 2020

Objective To introduce an anterior surgical technique for cervical ossification of posterior longitudinal ligament (OPLL) extending to C2. Methods A total of 29 patients with multilevel OPLL extending to C2 underwent surgery from January 2016 to January 2019. The rationale of our surgical technique is to transect the ossified ligament at the level of C2/3, dividing OPLL into two parts. OPLL behind C2 vertebra is reserved as “focus exclusion”, and OPLL below C2 is performed anterior controllable antedisplacement and fusion (ACAF). Neurological condition was evaluated using the Japanese Orthopeadic Association (JOA) scoring system and its improvement ratio. Radiological assessment included type and extent of OPLL, occupying rate, thickness and length of ossified mass, and curvature of spinal cord. Surgery- and implant-related complications were recorded. Results The mean JOA score increased from 9.4 to 15.8 points at last follow-up, with a significant improvement (P<0.01). The mean preoperative length of the ossified mass behind C2 was 15.4 mm, and its thickness was 2.2 mm, with no significant progression at last follow-up (15.3 mm and 2.2 mm, P>0.05). There was also no statistical difference in OPLL thickness at the largest OR level between preoperation and last follow-up (7.4mm vs. 7.3mm, P>0.05). Four patients presented with cerebrospinal fluid leakage, one with screw displacement and one with dysphagia. Conclusions For patients with cervical OPLL extending to C2, exclusion of ossified ligaments behind C2 combined with ACAF below C2 is an effective and alternative technique.

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 Multi-Modal Spinal Cord Evoked Potentials

Article

Oct 2020
SPINE

Study design: A retrospective study of prospectively collected data. Objective: 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). Summary of background data: Appropriate assessments of dynamic factors should reveal hidden spinal cord compression and provide useful information for choosing surgical procedures. Methods: 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. Results: 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 degrees, odds ratio: 0.69, 95%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. Conclusion: 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.

Vertebral Body Sliding Osteotomy for Cervical Myelopathy With Rigid Kyphosis

Article

Full-text available

Sep 2020

Cervical spondylotic myelopathy is surgically demanding when associated with rigid kyphosis. Posterior surgery cannot restore cervical lordosis, and adequate decompression is not possible with rigid kyphosis. Vertebral body sliding osteotomy (VBSO) is a safe and novel technique for anterior decompression in patients with multilevel cervical spondylotic myelopathy. It is safe in terms of dural tear, pseudarthrosis, and graft dislodgement, which are demonstrated at high rates in anterior cervical corpectomy and fusion. In addition, VBSO is a powerful method for restoring cervical lordosis through multilevel anterior cervical discectomy and fusion above and below the osteotomy level. It may be a feasible treatment option for patients with cervical spondylotic myelopathy and kyphotic deformity. This is a technical note and literature review that describes the procedures involved in VBSO.

Degenerative cervical myelopathy — update and future directions

Article

Jan 2020

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults worldwide. DCM encompasses various acquired (age-related) and congenital pathologies related to degeneration of the cervical spinal column, including hypertrophy and/or calcification of the ligaments, intervertebral discs and osseous tissues. These pathologies narrow the spinal canal, leading to chronic spinal cord compression and disability. Owing to the ageing population, rates of DCM are increasing. Expeditious diagnosis and treatment of DCM are needed to avoid permanent disability. Over the past 10 years, advances in basic science and in translational and clinical research have improved our understanding of the pathophysiology of DCM and helped delineate evidence-based practices for diagnosis and treatment. Surgical decompression is recommended for moderate and severe DCM; the best strategy for mild myelopathy remains unclear. Next-generation quantitative microstructural MRI and neurophysiological recordings promise to enable quantification of spinal cord tissue damage and help predict clinical outcomes. Here, we provide a comprehensive, evidence-based review of DCM, including its definition, epidemiology, pathophysiology, clinical presentation, diagnosis and differential diagnosis, and non-operative and operative management. With this Review, we aim to equip physicians across broad disciplines with the knowledge necessary to make a timely diagnosis of DCM, recognize the clinical features that influence management and identify when urgent surgical intervention is warranted.

Predictive Effect of Cervical Sagittal Parameters on Conservative Treatment of Single-Segment Cervical Spondylotic Radiculopathy

Article

Nov 2019

Study design: A retrospective study. Objective: To explore (1)whether the cervical sagittal parameters affect the conservative treatment of single-segment cervical spondylotic radiculopathy and (2)whether the conservative treatment of single-segment cervical spondylotic radiculopathy can be predicted by cervical sagittal parameters. Summary of background data: The treatment of cervical spondylotic radiculopathy is currently treated with a stepwise treatment, and conservative treatment is recommended. However, there is no sufficient evidence to prove the efficacy of conservative treatment. Methods: From January 2013 to January 2018, 121 patients with single-segment cervical spondylotic radiculopathy were enrolled. The inclusion criteria included complete cervical lateral radiographs. The following radiographic parameters were measured:(1)C0-C2 Cobb angle; (2)C2-C7 Cobb angle(CL); (3)C7 slope(C7S); (4)Neck tilt(NT); (5)Thoracic inlet angle(TIA); (6)T1 slope(T1S); (7)C2-C7 sagittal vertical axis(SVA); (8)Cervical tilt; (9)Cranial tilt; (10)Cervical curvature index (CCI). Assessment of cervical spine function and quality of life by VAS and NDI. According to the therapeutic effect, they were divided into group A (conservative treatment effective group) and group B (conservative treatment ineffective group). Conservative treatment was effectively defined as conservative treatment for 3 months (one non-steroidal analgesic, one neurotrophic drug, and supplemented by cervical traction and neck support brake), then NDI score was reduced by 60% after the treatment. Pearson correlation coefficient was used to calculate the correlation between each sagittal parameter and functional score. Logistic regression analysis and ROC curve were used to determine independent risk factors and critical values. Results: In the conservative treatment group (group A): the pre-treatment NDI score was significantly positively correlated with the pre-treatment VAS score, and negatively correlated with CL, C7S, TIA, T1S, cervical tilt, and CCI. In the conservative treatment ineffective group (group B): the pre-treatment NDI score was significantly positively correlated with the pre-treatment VAS score and NT, and negatively correlated with age, CL, C7S, T1S, cervical tilt, and CCI. By logistic regression analysis and ROC curve, we obtained that the larger C2-7 Cobb angle before treatment was the only independent risk factor for conservative treatment (P<0.001). When the C2-7 Cobb angle >7.7°, the patient had greater possibility of conservative treatment was effective. Conclusion: In patients with single-segment cervical spondylotic radiculopathy, the larger C2-7 Cobb angle before treatment is the only independent risk factor for conservative treatment (P<0.001). When the C2-7 Cobb angle >7.7°, it is much more possible that the conservative treatment is effective.

Spinal alignment, surgery, and outcomes in cervical deformity: A practical guide to aid the spine surgeon

Article

Aug 2019
CLIN NEUROL NEUROSUR

Compared to the thoracolumbar spine, the literature on cervical spine alignment is scarce. While a consistent number of articles have been published, few analyze the ideal surgical approaches for each type of deformity and the optimal amount of correction to achieve. This paper provides a comprehensive review of current literature on cervical spinal deformities (with or without myelopathy) and their surgical management; it is our goal to create a framework on which surgical planning can be made. A general assessment of the actually utilized parameters and correlation between the cervical and thoracolumbar spine alignment is presented. Moreover, we provide an analysis of cervical surgical approaches (anterior, posterior, or combined), techniques (laminoplasty, laminectomy and fusion, anterior cervical discectomy and fusion, corpectomy), and their indications. Finally, a complete evaluation of outcomes and postoperative health-related quality of life (HRQOL) measures based on questionnaires (NDI, VAS, SF-36, mJOA) is discussed. Several prospective studies would be useful in understanding how cervical alignment may be important in the assessment and treatment of cervical deformities with or without myelopathy. In particular, future works should concentrate on the correlation between cervical alignment parameters, disability scores, and myelopathy outcomes. We propose, via comprehensive literature review, a guide of practical key points on surgical techniques, cervical alignment, and symptom improvement goals surgeons should aim to achieve for each patient.

Short-term foetal immobility temporally and progressively affects chick spinal curvature and anatomy and rib development

Article

Full-text available

Jan 2019
EUR CELLS MATER

Congenital spine deformities may be influenced by movements in utero, but the effects of foetal immobility on spine and rib development remain unclear. The purpose of the present study was to determine (1) critical time-periods when rigid paralysis caused the most severe disruption in spine and rib development and (2) how the effects of an early, short-term immobilisation were propagated to the different features of spine and rib development. Chick embryos were immobilised once per single embryonic day (E) between E3 and E6 and harvested at E9. To assess the ontogenetic effects following single-day immobilisation, other embryos were immobilised at E4 and harvested daily between E5 and E9. Spinal curvature, vertebral shape and segmentation and rib development were analysed by optical projection tomography and histology. The results demonstrated that periods critical for movement varied for different aspects of spine and rib development. Single-day immobilisation at E3 or E4 resulted in the most pronounced spinal curvature abnormalities, multiple wedged vertebrae and segmentation defects, while single-day immobilisation at E5 led to the most severe rib abnormalities. Assessment of ontogenetic effects following single-day immobilisation at E4 revealed that vertebral segmentation defects were subsequent to earlier vertebral body shape and spinal curvature abnormalities, while rib formation (although delayed) was independent from thoracic vertebral shape or curvature changes. A day-long immobilisation in chicks severely affected spine and rib development, highlighting the importance of abnormal foetal movements at specific time-points and motivating targeted prenatal monitoring for early diagnosis of congenital scoliosis.

Surgical Indication and Challenges of Anterior or Posterior Approach for Cervical Degenerative Disease

Article

Apr 2018

Nobuyuki Shimokawa

Over the years, there have been many discussions on the selection indication for surgical approaches to cervical spine diseases including OPLL, especially cervical spine degenerative diseases. The idea of approaching the lesion anteriorly with the main seat in the ventral side of the cervical spine is a perfect logical strategy and vice versa. However anterior intervertebral bony fusion is essential, except for some surgical techniques, after correct decompression of the spinal cord/nerve root from the ventral side. There is also the issue of adjacent intervertebral disorders after spinal fusion occurring, and it is more important to carefully observe long-term follow-up in Japan, where the frequency of developmental spinal canal stenosis is higher than overseas. As a surgical indication for the anterior or posterior approach of current textbook-like cervical spine degenerative disease: 1) anterior approach if the lesion is within 2 vertebrae, posterior approach if more. 2) In the past, those with kyphosis were contraindications for posterior decompression, but the posterior decompression effect of the spinal cord is expected if the cervical spine arrangement has a local kyphosis of 13 degrees or less is present. 3) For non-elderly patients with a background of developmental spinal canal stenosis, there is another strategy to choose the posterior approach first due to adjacent intervertebral disorders. 4) The OPLLs with a K-Line (+) is indicates a posterior approach, on the other hand, ones with a K-Line (−) indicate an anterior approach. Although each approach is a safe and established procedure, it is important to understand the type and frequency of complications and tips to prevent them. Regarding selecting the best surgical approach for cervical disorders, it is not a uniform one, but it must be generally selected considering age, general condition, and the social and family background of each patient all together. In addition, the use of artificial intervertebral discs will begin soon in Japan. It seems that improvements will also be made in anterior/posterior surgical selection for cervical degenerative disorders. © 2018, Japanese Congress of Neurological Surgeons. All rights reserved.

Die zervikale spondylotische Myelopathie: Indikationsstellung für eine chirurgische Therapie

Article

Apr 2018

Background: The pathogenesis of cervical spondylotic myelopathy (CSM) is often multifactorial. Hence, the treatment of this disease requires a differentiated surgical approach in order to adequately address the underlying pathology. Purpose: The aim of this review is to identify factors that influence the choice of treatment strategy and to summarize them in an algorithm that serves as a decision aid in choosing the optimal indication for surgical treatment. An attempt is made to define the threshold values for the indication of surgical treatment and to discuss the ideal timing for performing surgery. Materials and methods: On the basis of the published data, the influencing factors on the prognosis of CSM, as well as surgical approaches are discussed. Results: Circumferential spinal cord compression, a sharply defined myelopathy signal in the T2-weighted MRI sequence, and segmental instability at the level of the myelopathy signal mean an unfavorable prognosis for the worsening of CSM. The most important factors that influence the choice of the surgical access point are the sagittal profile of the cervical spine, the extent of myelopathy, the extent of stenosis, and the location of the myelopathy-inducing pathology. Previously existing neck pain and prior cervical surgery must also be considered. Discussion: On the basis of the research carried out, we developed an algorithm that could serve as an aid in choosing the right treatment in the setting of cervical spondylotic myelopathy.

Association between cervical lordotic curvature and cervical muscle cross-sectional area in patients with loss of cervical lordosis: Extensor Weakness in Loss of Cervical Lordosis

Article

Mar 2018

Introduction: Disruption of the cervical lordotic curve can cause undesirable symptoms such as neck pain, and cord compression. The purpose of this study was to investigate the biomechanics of loss of cervical lordosis by measuring the cross‐sectional area (CSA) of the cervical muscles using magnetic resonance imaging (MRI), and to determine the relationship between cervical lordosis angle and cervical muscle status. Materials and Methods: The cervical lordosis angle was measured on standing lateral plain radiography using the posterior tangent technique in patients who complained of neck pain. The CSAs of the cervical flexor muscles including the longus cervicis and longus capitis, the cervical extensor muscles including the splenius capitis and semispinalis capitis, and the sternocleidomastoid muscle, were measured at the maximum levels by axial T1‐weighted MRI. We compared neck muscle CSAs between the two groups, the correlation with cervical lordosis angle, and muscle status including CSA and imbalance. Results: The CSA of the semispinalis capitis was significantly lower in the loss of cervical lordosis group, and the ratio of cervical flexor to extensor was significantly different between the two groups (P<0.05). Partial correlation analysis revealed that the cervical lordotic angle was significantly positively correlated with the ratio of flexor to extensor muscle CSAs (P<0.05). Conclusions: There is a significant relationship between cervical muscle imbalance, including extensor muscle weakness, and loss of cervical lordosis. An exercise program focusing on cervical extensor muscle strengthening and restoring the balance of flexor and extensor muscles is recommended for patients with loss of cervical lordosis. This article is protected by copyright. All rights reserved.

The Effect of Technological Devices on Cervical Lordosis

Article

Full-text available

Mar 2018

PURPOSE: There is a need for cervical flexion and even cervical hyperflexion for the use of technological devices, especially mobile phones. We investigated the effect of this use on the cervical lordosis angle. MATERIAL AND METHODS: A group of 156 patients who applied with only neck pain between 2013–2016 and had no additional problems were included. Patients are specifically questioned about mobile phone, tablet, and other devices usage. The value obtained by multiplying the year of usage and the average usage (hour) in daily life was determined as the total usage value (an average hour per day x year: hy). Cervical lordosis angles were statistically compared with the total time of use. RESULTS: In the general ROC analysis, the cut-off value was found to be 20.5 hy. When the cut-off value is tested, the overall accuracy is very good with 72.4%. The true estimate of true risk and non-risk is quite high. The ROC analysis is statistically significant. CONCLUSION: The use of computing devices, especially mobile telephones, and the increase in the flexion of the cervical spine indicate that cervical vertebral problems will increase even in younger people in future. Also, to using with attention at this point, ergonomic devices must also be developed.

Article

Feb 2018

Hany Abdel Gawwad Soliman

Study design: A cross-sectional study OBJECTIVE.: The aim of this study was to study the health-related quality of life (HRQOL) of adolescents with severe untreated congenital kyphosis (CK) and congenital kyphoscoliosis (CKS) in a developing country. Summary of background data: Surgical intervention is generally indicated early in patients with progressive CK or CKS to prevent the progression of deformity and to improve the quality of life of the patients. HRQOL of adolescents with untreated CK and CKS in developing countries has never been investigated. Methods: Arabic version of the Scoliosis Research Society 22 revision (SRS-22r) questionnaire used to study HRQOL of adolescents with severe untreated CK or CKS in a dev eloping country. Results: A total of 134 adolescent (mean age 17.1 years) completed SRS-22r questionnaire: 38 patients with CK from 80° to 110° (group 1), 24 patients with CK > 110° (group 2), 27 patients with CKS (group 3), and 45 healthy controls (group 4). Group 1 had significant lower scores than group 4 in all SRS 22r domains (P < 0.001). Scores of all domains except pain showed significant (P < 0.001) decrease with increase of the severity of CK. Group 3 had significant lower scores than group 2 in all SRS-22r domains except mental health. Satisfaction domain had significant lower scores than all other SRS-22r domains for group 1, 2, and 3. All patients of groups 2 and 3 gave the minimum answers for satisfaction domain questions. A total of 69%, 84% and 94% of group 1, 2, and 3, respectively, gave the minimum answer when asked whether their back condition affects their personal relationships. Female patients of group 1, 2, and 3 had significant lower scores for self-image domain. Conclusion: HRQOL is severely affected in adolescents with untreated severe CK and CKS in a developing country. Level of evidence: 3.

Importance of Sagittal Alignment of the Cervical Spine in the Management of Degenerative Cervical Myelopathy

Article

Jan 2018
NEUROSURG CLIN N AM

Cervical spine sagittal malalignment correlates with worse symptoms and outcomes in patients with degenerative cervical myelopathy (DCM), and should influence surgical management. An anterior versus posterior surgical approach may not significantly change outcomes in patients with preoperative lordosis; however, most studies suggest improved neurologic recovery among kyphotic patients after adequate correction of local sagittal alignment through an anterior or combined anterior-posterior approach. There are no comprehensive guidelines for DCM management in the setting of cervical malalignment; therefore, surgical management should be tailored to individual patients and decisions made at the discretion of treating surgeons with attention to basic principles.

Cervical Sagittal Range Of Motion As A Predictor Of Symptom Severity In Cervical Spondylotic Myelopathy

Article

Oct 2017

Study design: Retrospective review of radiographic data and functional outcomes. Objective: Evaluate whether myelopathy symptom severity upon presentation corresponds to sagittal plane alignment or non-myelopathy symptoms, such as pain, in patients with cervical spondylotic myelopathy (CSM). Summary of background data: Cervical sagittal balance is an important parameter in the outcome of surgical reconstruction. However, the effect of sagittal alignment on symptom severity in patients who have not undergone spine surgery is not well defined. Methods: A consecutive series of CSM patients was identified at an academic institution. Preoperative radiographs were analyzed for sagittal vertical axis (C2SVA), C7 slope (C7S), C2-C7 angle in neutral (C27N), flexion (C27F), and extension (C27E), and range of motion (C27ROM). Neutral alignment was categorized as lordotic, kyphotic or sigmoid/straight. Outcomes collected were SF-12, neck disability index, arm pain, neck pain, and modified JOA (mJOA). Pearson coefficients determined correlations between radiographic and outcome parameters. Multivariate regression evaluated predictive factors of mJOA. Results: Radiographic parameters did not correlate with pain. Increasing age, smaller C27ROM, and smaller flexion angles correlated to lower (more severe) baseline mJOA scores. ROM (and not static alignment) was the only significant predictor of mJOA in the multivariate regression. Despite significant radiographic differences between lordotic, kyphotic, and sigmoid/straight alignment groups, myelopathy severity did not differ between these groups. Conclusions: Static, neutral alignment, including SVA and lordosis, did not correlate with myelopathy or pain symptoms. Greater C27ROM and increased maximal flexion corresponded to milder myelopathy symptoms, suggesting that patients with myelopathy may compensate for cervical stenosis with hyperflexion, similar to that which is observed in the lumbar spine. In a CSM patient population, dynamic motion and compensatory deformities may play a more significant role in myelopathy symptom severity than what can be discerned from standard, neutral position radiographs. Level of evidence: 3.

Decreased choline acetyltransferase activity in the murine spinal cord motoneurons under chronic mechanical compression

Article

Full-text available

Dec 1997
SPINAL CORD

The tiptoe-walking Yoshimura (twy) mouse is a model of chronic spinal cord compression caused by ossification of intraspinal ligaments. Choline acetyltransferase (CAT), which is known to be a specific marker of cholinergic neurons, best reflects spinal motoneuron function. Changes in CAT immunoreactivity following chronic spinal cord compression in twy mice were investigated quantitatively in order to elucidate spinal motoneuron functional changes according to the degree and direction of compression. Thirty 24-week-old twy mice were used in this study. They were divided into three groups according to the direction of spinal cord compression (anterior, posterior, and lateral) and the CAT immunoreactivities in whole sections of their upper cervical spinal cords were investigated quantitatively using a fluorescence microphotometry system. The lateral compression group showed histological spinal motoneuron atrophy and loss on the compressed, but not the non-compressed, side. Spinal motoneuron atrophy and loss were observed when the severity of spinal canal stenosis due to the ossified lesion, expressed as the occupation rate, was 30% or more, but the spinal motoneurons appeared normal when it was below 30%. The CAT immunofluorescence intensity of the anterior horn showed a linear negative correlation with the degree of canal stenosis. When the occupation rate was below 20%, the CAT immunofluorescence intensities in the anterior horns of the compression and control groups did not differ significantly. The CAT immunofluorescence intensity of twy mice with occupation rates of 20% or more were significantly lower than that of those with occupation rates below 20%. Furthermore, the CAT immunofluorescence intensity was significantly lower on the compressed than the non-compressed side of the lateral compression group. Thus, our findings indicate that an occupation rate of about 20% may be the critical level for functional changes in the spinal motoneurons.

Experimental cervical myelopathy: Effects of ischemia and compression of the canine cervical spinal cord

Article

Aug 1975
J NEUROSURG

The authors report experiments designed to test the effect of regional ischemia induced by selective vascular ligations and anterior compression of the cervical cord at two adjacent segments (C-4, C-5) in the same dog. They conclude that local ischemia of the cervical cord, caused by local deformation, when superimposed on a regional reduction in spinal cord blood flow, accounts for the myelopathy of cervical spondylosis whether produced experimentally in animals or occurring naturally in man.

Neurofibromatosis of the cervical spine. A report of eight cases

Article

Aug 1992
J BONE JOINT SURG BR

Eight patients with neurofibromatosis presented with symptoms of cervical spine involvement over a period of 17 years, five of them within the second decade of life. The symptoms included neurological deficit in five, a neck mass in four, and deformity in three; only two complained of pain. Osteolysis of vertebral bodies with kyphosis of more than 90 degrees was the most common radiological feature. Posterior fusion failed in the one patient in whom it was performed. Good results were achieved by anterior fusion, alone, or combined with posterior fusion. Surgical complications included one death in a patient with a malignant neurofibroma, and one case of transient neurological deterioration.

Congenital kyphosis: Its natural history and treatment as observed in a study of one hundred and thirty patients

Article

Apr 1973

The three types, Type I (absence of vertebral bodies), Type II (failure of segmentation), and Type III (both), were seen in all sites in the spine, but paraplegia only occurred in unstable Type I lesions (six of twenty-four untreated), some with only moderate kyphosis, and without rapid progression. Without treatment, progression of the kyphos was the rule, averaging 7 degrees per year (thirty patients) and reaching a maximum during the adolescent growth spurt. Brace treatment was ineffective and forty-four patients had surgery. Pseudarthrosis in posterior fusions occurred in half the patients (fifteen of twenty-eight) and in only two of sixteen with combined anteroposterior fusions. Correction with or without Harrington apparatus with posterior fusions before the age of three is the recommended treatment. Where an angulation of over 50 degrees was present, anterior fusion was preferred.

Congenital kyphoscoliosis

Article

Jul 1973
Isr J Med Sci

J.I.P. James

The blood supply of the spinal cord. A critical vascular zone in spinal surgery

Article

Jun 1974
J BONE JOINT SURG BR

G F Dommisse

1. A high incidence of paraplegia following operations for the correction of severe scoliosis in adults led to an investigation of the normal blood supply of the human spinal cord. 2. This entailed three methods of study: micro-dissection of the vessels of the spinal cord in thirty-five cadavers; radiological measurements of the spinal canal in fifty healthy subjects; and a study of the macerated spinal column in six adult cadavers. 3. The blood supply of the spinal cord is shown to be least rich, and the spinal canal narrowest, from the T.4 to approximately the T.9 vertebral level. This is named the critical vascular zone of the spinal cord, the zone in which interference with the circulation is most likely to result in paraplegia.

Neurofibromatosis with paraplegia. Report of eight cases

Article

Aug 1969

Microvasculature of the human spinal cord

Article

Sep 1971
J NEUROSURG

Ian M. Turnbull

The regional differences in spinal microvasculature are outlined from microangiographic examination of the human spinal cord. Five to eight central arteries arise from each centimeter length of the anterior spinal artery in the cervical region, two to five in the thoracic region, and five to twelve in the lumbosacral region. The central arteries in the cervical and lumbar cord in addition to being more numerous are of larger caliber than those in the thoracic cord. Terminal arterioles do not interconnect within the spinal cord but give rise to interlocking capillary networks, which are more numerous in the gray than in the white matter. Arteries in the lateral columns are elongated with flattening of the spinal cord due to a space-occupying lesion. Correlation of the distortion of the small vessels with various types of spinal cord displacement is described.

Effects of Mechanical Stresses on the Spinal Cord in Cervical Spondylosis

Article

Aug 1966
J NEUROSURG

Neurologic Deficits Secondary to Spinal Deformity: A Review of the Literature and Report of 43 Cases

Article

Jul 1980

Forty-three cases of neurologic complications of untreated spinal deformities are reviewed. Kyphosis, averaging 95 degrees, was present in all but one patient. The most common deformity was a congenital kyphosis, present in 17 patients. The complication was more common in males, in the presence of thoracic deformities, and in the second decade. Treatment consisted of anterior spinal cord decompression in 25 patients, laminectomy in ten, Capener decompression in six, correction and fusion in five, and Hyndman-Schneider decompression in three. Laminectomy gave the worst results; six of ten patients who received this treatment showed deterioration. Anterior cord decompression gave the best results, with 16 of 25 showing improvement. A treatment plan for this complication is proposed. A plea for prevention is made, as it is far preferable to avoid this dreaded complication by early fusion of kyphotic problems.

A new breed of mouse showing multiple osteochondral lesions - twy mouse

Article

Feb 1981
Ryumachi Ryumachi

In Japan, a new breed of mouse showing multiple osteochondral lesions was discovered and was named the twy mouse (tiptoe walking-Yoshimura). This mouse line is characterized by tiptoe walking, stiffness of the vertebral column and limb joints, and later motor paresis. Calcification and ossification bridging adjacent vertebral bodies are seen in association with degeneration and destruction of the intervertebral discs. In limb joints, destruction of articular cartilage and synovial cell proliferation with or without inflammatory cell infiltration are observed. Calcification in and around the joint capsule is also noticed. Serum calcium level is within normal limits. These characteristics are inherited through an autosomal recessive single gene. This may be a useful model simulating various human diseases including ankylosing spondylitis, osteoarthritis and others.

Experimental chronic compressive cervical myelopathy

Article

Nov 1993
J NEUROSURG

A canine model simulating both cervical spondylosis and its results in delayed progressive myelopathy is presented. This model allowed control of compression, an ongoing assessment of neurological deficits, and evaluation using diagnostic images, frequent electrophysiological tests, local blood flow measurements, and postmortem histological examinations. Subclinical cervical cord compression was achieved in 14 dogs by placing a Teflon washer posteriorly and a Teflon screw anteriorly, producing an average of 29% stenosis of the spinal canal. Four dogs undergoing sham operations were designated as controls. Twelve of the animals undergoing compression developed delayed and progressive clinical signs of myelopathy, with a mean latent period to onset of myelopathy of 7 months. Spinal cord blood flow studies using the hydrogen clearance method showed a significant transient increase in blood flow immediately after compression and a decrease before sacrifice. Somatosensory evoked potential studies indicated progressive deterioration during the period of compression. Magnetic resonance images revealed intramedullary changes. Histological studies showed abnormalities overwhelmingly within the gray matter, including changes in vascular morphology, loss of large motor neurons, necrosis, and cavitation. Axonal degeneration and obvious demyelination were rarely seen. The most profound morphological changes occurred at the site of greatest compression. It is proposed that a momentary arrest of microcirculation occurs during extension of the neck because of loss of the reserve space in the compromised spinal canal. This microcirculatory disturbance is predominant in the watershed area of the cord and mainly affects the highly vulnerable anterior horn cells, leading to neuronal death, necrosis, and eventual cavitation at the junction of the dorsal and anterior horns. Additional supportive evidence of this hypothesis was derived from the literature.

Spinal cord compression studies: I. Experimental Techniques to Produce Acute and Gradual Compression

Article

Jan 1954
Arch Neurol Psychiatr

THERE IS much controversy over the proper treatment of acute and chronic spinal cord compression. Not everyone agrees, for instance, on the best time to operate in cases of acute compression of the spinal cord or cauda equina, or whether to operate at all. Some of the signs and symptoms accompanying these lesions, moreover, are perplexing, and even misleading. Kahn¹ has called attention to the primary lateral sclerosis syndrome resulting from anterior spinal cord compression. Only recently, indeed, several well-known neurologists made a diagnosis of primary lateral sclerosis in a quadriplegic woman. At operation, however, one of us (I. M. T.) removed a ventrally placed meningioma from the cervical portion of her spinal cord. On occasion, also, "neoplasms may simulate subacute combined degeneration of the spinal cord."² In an effort to throw light on these problems, we have submitted them to experimental analysis in laboratory animals. The project