Effective lordosis: analysis of sagittal spinal canal alignment in cervical spondylotic myelopathy

Object Analysis of cervical sagittal deformity in patients with cervical spondylotic myelopathy (CSM) requires a thorough clinical and radiographic evaluation to select the most appropriate surgical approach. Angular radiographic measurements, which are commonly used to define sagittal deformity, may not be the most appropriate to use for surgical planning. The authors present a simple straight-line method to measure effective spinal canal lordosis and analyze its reliability. Furthermore, comparisons of this measurement to traditional angular measurements of sagittal cervical alignment are made in regards to surgical planning in patients with CSM. Methods Twenty preoperative lateral cervical digital radiographs of patients with CSM were analyzed by 3 independent observers on 3 separate occasions using a software measurement program. Sagittal measurements included C2–7 angles utilizing the Cobb and posterior tangent methods, as well as a straight-line method to measure effective spinal canal lordosis from the dorsal-caudal aspect of the C2–7 vertebral bodies. Analysis of variance for repeated measures or Cohen 3-way (kappa) correlation coefficient analysis was performed as appropriate to calculate the intra- and interobserver reliability for each parameter. Discrepancies in angular and effective lordosis measurements were analyzed. Results Intra- and interobserver reliability was excellent (intraclass coefficient > 0.75, kappa > 0.90) utilizing all 3 techniques. Four discrepancies between angular and effective lordotic measurements occurred in which images with a lordotic angular measurement did not have lordosis within the ventral spinal canal. These discrepancies were caused by either spondylolisthesis or dorsally projecting osteophytes in all cases. Conclusions Although they are reliable, traditional methods used to make angular measurements of sagittal cervical spine alignment do not take into account ventral obstructions to the spinal cord. The effective lordosis measurement method provides a simple and reliable means of determining clinically significant lordosis because it accounts for both overall alignment of the cervical spine as well as impinging structures ventral to the spinal cord. This method should be considered for use in the treatment of patients with CSM.

Download Full-text

Biomechanical Effects of Laminoplasty and Laminectomy on the Stability of Cervical Spine

ASME 2011 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2011-53252 ◽

2011 ◽

Cited By ~ 1

Author(s):

Swathi Kode ◽

Nicole A. Kallemeyn ◽

Joseph D. Smucker ◽

Douglas C. Fredericks ◽

Nicole M. Grosland

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

North America ◽

Spinal Canal ◽

Cervical Spondylotic Myelopathy ◽

Nerve Roots ◽

Canal Diameter ◽

The World ◽

The Stability

Cervical spondylotic myelopathy is the most common spinal cord disorder in persons more than 55 years of age in North America and perhaps in the world [7]. It is a chronic degenerative condition of the cervical spine that results in the reduction of spinal canal diameter and thereby compresses the spinal cord and the associated nerve roots [1].

Download Full-text

I traumi cervicali

Rivista di Neuroradiologia ◽

10.1177/197140099701000107 ◽

1997 ◽

Vol 10 (1) ◽

pp. 63-102 ◽

Cited By ~ 1

Author(s):

N. Colombo ◽

C. Maccagnano ◽

C. Corona ◽

A. Beltramello ◽

G. Scialfa

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Head Trauma ◽

Acute Phase ◽

Spinal Canal ◽

Cervical Spinal Cord ◽

Spinal Trauma ◽

Diagnostic Modality ◽

Neurologic Deficits ◽

Cervical Injuries

Injury to the cervical spinal cord is a major health problem owing to its frequency and to the often devastating sequelae of serious trauma with respect to long-term disability for the patient. Cervical injuries are often reported in association with head trauma and cervical spinal cord injury appears to be a major contributing factor in acute death secondary to traffic accidents producing severe head injuries. A high incidence of neurological deficits is reported in cervical spinal trauma, but cervical injuries can escape detection in the acute phase if clinically silent or in patients unconscious from to head trauma. The most important predisposing factor in the concomitant occurrence of head and neck trauma is transmission of forces through the cranial vault to the cervical spine. Other underlying cervical spine diseases, either congenital or developmental, may also predispose to the development of cervical injuries. The spine includes bony-ligamentous structures and nervous structures. The bony-ligamentous involucre is anatomically predisposed to perform three major tasks: 1) maintenance of spinal statics; 2) mobilization in the three anatomic planes and 3) protection of nervous and vascular structures inside the spinal canal. The cervical spine is subjected to varying forces of flexion, flexion-rotation, extension and vertical compression which result in damage to the different components of the spine when they are applied beyond physiological limits. Biomechanical considerations of the different motion patterns that occur in the cervical spine are essential to understand the contribution of mechanical stresses to the development of specific spinal injuries. This chapter tackles the problem of a logical management of cervical spinal trauma based on clinical presentation to: a) identify the preferential diagnostic modality to investigate that type of injury (conventional X-Ray, Computed Tomography, Magnetic Resonance); b) interpret images, indipendently from the diagnostic modality utilized, considering the cause-effect relation between the traumatic force and the anatomic-functional structures involved by the trauma. The clinical picture may include pain, movement limitations and/or radiculo-myelopathy. Cerebral neurologic deficits can be the consequence of traumatic damage to the carotid and vertebral artery system in the neck. Evaluation of injury instability is one of the main goals of radiographic investigation. One classifies bony instability which is temporary, as opposed to disco-ligamentous instability which is permanent and usually requires surgical stabilization, and mixed instability. Conventional lateral and antero-posterior radiographs should be initially performed in patients with cervical trauma and in polytrauma and comatous patients who are difficult to assess clinically. They effectively screen vertebral fractures, vertebral body and facet dislocations and pre-vertebral soft tissue swelling. However, ligament disruption and instability can be underestimated by a normal disco-vertebral alignment. Dynamic flexion-extension views, useful to reveal such an instability, should never be performed in the acute phase particularly if fractures and neurologic deficits are present. CT scan, in addition, has several advantages: the axial plane provides an optimal view of the size and shape of the spinal canal, bony fragments and foreign bodies within the canal are very well depicted, posterior element fractures are better visualized. A preexsisting spondylotic narrow canal is well evaluated by CT as are post-traumatic disc herniations. Widening of the apophyseal joints, suggesting disruption of facet capsules and spinal instability, is best demonstrated by CT. However, CT has some limitations in evaluating ligament instability since it is performed in the neutral position and, in addition, it cannot visualize the medulla and its potential traumatic lesions. After the introduction of MRI, myelography and CT-myelography are no longer used to investigate cervical spine lesions involving cord and nerve roots. MRI should be performed in every patient presenting with neurologic deficits. The usefulness of MR is in detecting extradural compressive lesions like disc herniation and haematomas that need to be decompressed surgically. MRI can also evaluate ligamentous integrity and disk rupture. Bony fractures are revealed by MRI either by signal or morphologic alterations of vertebral bodies, but thin, linear fractures are less well identified than with CT. One of the main advantages of MRI is the direct identification of intrinsic cord pathology such as cord contusion and haemorrhage. Cord haemorrhage seems to be predictive of a complete lesion and of poor outcome. Therefore MRI is proposed to assess the prognosis of traumatic cord lesions, the best time for imaging ranging between 24 and 72 hours after injury.

Download Full-text

Anatomical features of the cervical spinal canal in Chiari I deformity with presyrinx: A case-control study

The Neuroradiology Journal ◽

10.1177/1971400917718842 ◽

2017 ◽

Vol 30 (5) ◽

pp. 405-409 ◽

Cited By ~ 2

Author(s):

Judith A Gadde ◽

Vinil Shah ◽

Greta B Liebo ◽

Geir A Ringstad ◽

I Jonathan Pomeraniec ◽

...

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Spinal Canal ◽

Statistical Significance ◽

Upper Cervical Spine ◽

Tonsillar Herniation ◽

Cerebrospinal Fluid Flow ◽

Chiari I ◽

The Difference ◽

Normal Controls

Purpose The relationship between syringomyelia and presyrinx, characterized by edema in the spinal cord, has not been firmly established. Patients with syringomyelia have abnormal spinal canal tapering that alters cerebrospinal fluid flow dynamics, but taper ratios in presyrinx have never been reported. We tested the hypothesis that presyrinx patients have abnormal spinal canal tapering. Materials and methods At six medical institutions, investigators searched the PACS system for patients with Chiari I and spinal cord edema unassociated with tumor, trauma, or other evident cause. In each case taper ratios were calculated for C1 to C4 and C4 to C7. In two age- and gender-matched control groups, Chiari I patients with no syringomyelia and patients with normal MR scans, the same measurements were made. Differences between groups were tested for statistical significance with t tests. Results The study enrolled 21 presyrinx patients and equal numbers of matched Chiari I and normal controls. C4 to C7 taper ratios were positive and steeper in presyrinx patients than in the normal controls ( p = 0.04). The upper cervical spine, C1 to C4, tapered negatively in cases and controls without significant differences between the groups. The difference in degree of tonsillar herniation was statistically significant between presyrinx patients and Chiari I controls ( p = 0.01). Conclusions Presyrinx patients have greater than normal positive tapering in the lower cervical spine and greater degree of tonsillar herniation than the controls.

Download Full-text

Congenital Cervical Spine Stenosis in a Multicenter Global Cohort of Patients With Degenerative Cervical Myelopathy: An Ambispective Report Based on a Magnetic Resonance Imaging Diagnostic Criterion

Neurosurgery ◽

10.1093/neuros/nyx521 ◽

2018 ◽

Vol 83 (3) ◽

pp. 521-528 ◽

Cited By ~ 5

Author(s):

Aria Nouri ◽

Lindsay Tetreault ◽

Satoshi Nori ◽

Allan R Martin ◽

Anick Nater ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Spinal Cord ◽

Cervical Spine ◽

Magnetic Resonance ◽

Surgical Outcomes ◽

Cervical Myelopathy ◽

Spinal Canal ◽

Resonance Imaging ◽

Baseline Severity ◽

Degenerative Cervical Myelopathy

Abstract BACKGROUND Congenital spinal stenosis (CSS) of the cervical spine is a risk factor for acute spinal cord injury and development of degenerative cervical myelopathy (DCM). OBJECTIVE To develop magnetic resonance imaging (MRI)-based criteria to diagnose preexisting CSS and evaluate differences between patients with and without CSS. METHODS A secondary analysis of international prospectively collected data between 2005 and 2011 was conducted. We examined the data of 349 surgical DCM patients and 27 controls. Spinal canal and cord anteroposterior diameters were measured at noncompressed sites to calculate spinal cord occupation ratio (SCOR). Torg–Pavlov ratios and spinal canal diameters from radiographs were correlated with SCOR. Clinical and MRI factors were compared between patients with and without CSS. Surgical outcomes were also assessed. RESULTS Calculation of SCOR was feasible in 311/349 patients. Twenty-six patients with CSS were identified (8.4%). Patients with CSS were younger than patients without CSS (P = .03) and had worse baseline severity as measured by the modified Japanese Orthopedic Association score (P = .04), Nurick scale (P = .05), and Neck Disability Index (P < .01). CSS patients more commonly had T2 cord hyperintensity changes (P = .09, ns) and worse SF-36 Physical Component scores (P = .06, ns). SCOR correlated better with Torg–Pavlov ratio and spinal canal diameter at C3 than C5. Patients with SCOR ≥ 65% were also younger but did not differ in baseline severity. CONCLUSION SCOR ≥ 70% is an effective criterion to diagnose CSS. CSS patients develop myelopathy at a younger age and have greater impairment and disability than other patients with DCM. Despite this, CSS patients have comparable duration of symptoms, MRI presentations, and surgical outcomes to DCM patients without CSS.

Download Full-text

ANTERIOR CERVICAL APPROACH FOR THE TREATMENT OF CERVICAL MYELOPATHY

Neurosurgery ◽

10.1227/01.neu.0000215399.67006.05 ◽

2007 ◽

Vol 60 (suppl_1) ◽

pp. S1-64-S1-70 ◽

Cited By ~ 19

Author(s):

Paul G. Matz ◽

Patrick R. Pritchard ◽

Mark N. Hadley

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Surgical Technique ◽

Cervical Myelopathy ◽

Cervical Spondylotic Myelopathy ◽

Clinical Symptoms ◽

Recovery Of Function ◽

Surgical Decompression ◽

Cervical Approach ◽

Anterior Cervical Approach

Abstract COMPRESSION OF THE spinal cord by the degenerating cervical spine tends to lead to progressive clinical symptoms over a variable period of time. Surgical decompression can stop this process and lead to recovery of function. The choice of surgical technique depends on what is causing the compression of the spinal cord. This article reviews the symptoms and assessment for cervical spondylotic myelopathy (clinically evident compression of the spinal cord) and discusses the indications for decompression of the spinal cord anteriorly.

Download Full-text

Cervical Spondylotic Myelopathy: Treatment with Posterior Decompression and Luque Rectangle Bone Fusion

Neurosurgery ◽

10.1227/00006123-199105000-00007 ◽

1991 ◽

Vol 28 (5) ◽

pp. 680-684 ◽

Cited By ~ 37

Author(s):

Paul Kurt Maurer ◽

Richard G. Ellenbogen ◽

James Ecklund ◽

Gary R. Simonds ◽

Bruce van Dam ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Canal ◽

Cervical Spondylotic Myelopathy ◽

Substantial Evidence ◽

Posterior Decompression ◽

Neurological Improvement ◽

Bone Fusion ◽

Dynamic Factors ◽

Dynamic Forces ◽

Repetitive Trauma

Abstract Cervical spondylotic myelopathy appears to result from a combination of factors. The two major components are 1) compressive forces resulting from narrowing of the spinal canal, and 2) dynamic forces owing to mobility of the cervical spine. There is substantial evidence to suggest that the repetitive trauma to the spinal cord that is sustained with movement in a spondylotic canal may be a major cause of progressive myelopathy. Utilization of extensive anterior procedures that remove the diseased ventral features as well as eliminate the dynamic forces owing to the accompanying fusion have grown in popularity. Cervical laminectomy enlarges the spinal canal, but does not reduce the dynamic forces affecting the spinal cord, and may actually increase cervical mobility, leading to a perpetuation of the myelopathy. The authors propose the combination of posterior decompression and Luque rectangle bone fusion to deal with both the compressive and the dynamic factors that lead to cervical spondylotic myelopathy. Ten patients who had advanced myelopathy underwent the combined procedures. Nine of the 10 experienced significant neurological improvement, and the 10th has had no progression. The combination of posterior decompression and Luque rectangle bone fusion may offer a simple, safe, and effective alternative treatment for cervical spondylotic myelopathy.

Download Full-text

Laminectomy and Posterior Cervical Plating for Multilevel Cervical Spondylotic Myelopathy and Ossification of the Posterior Longitudinal Ligament: Effects on Cervical Alignment, Spinal Cord Compression, and Neurological Outcome

Neurosurgery ◽

10.1093/neurosurgery/52.5.1081 ◽

2003 ◽

Vol 52 (5) ◽

pp. 1081-1088 ◽

Cited By ~ 1

Author(s):

John K. Houten ◽

Paul R. Cooper

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Neurological Outcome ◽

Cervical Spondylotic Myelopathy ◽

Posterior Longitudinal Ligament ◽

X Rays ◽

Lateral Mass ◽

Japanese Orthopedic Association ◽

Curvature Index ◽

Muscle Groups

Abstract OBJECTIVE Multilevel anterior decompressive procedures for cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament may be associated with a high incidence of neurological morbidity, construct failure, and pseudoarthrosis. We theorized that laminectomy and stabilization of the cervical spine with lateral mass plates would obviate the disadvantages of anterior decompression, prevent the development of kyphotic deformity frequently seen after uninstrumented laminectomy, decompress the spinal cord, and produce neurological results equal or superior to those achieved by multilevel anterior procedures. METHODS We retrospectively reviewed the records of 38 patients who underwent laminectomy and lateral mass plating for cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament between January 1994 and November 2001. Seventy-six percent of patients had spondylosis, 18% had ossification of the posterior longitudinal ligament, and 5% had both. Clinical presentation included upper extremity sensory complaints (89%), gait difficulty (70%), and hand use deterioration (67%). Spasticity was present in 83%, and weakness of one or more muscle groups was seen in 79%. Spinal cord signal abnormality on sagittal T2-weighted magnetic resonance imaging (MRI) was seen in 68%. Neurological evaluation was performed using a modification of the Japanese Orthopedic Association Scale for functional assessment of myelopathy, the Cooper Scale for separate evaluation of upper and lower extremity motor function, and a five-point scale for evaluation of strength in individual muscle groups. Lateral cervical spine x-rays were analyzed using a curvature index to determine maintenance of alignment. Each surgically decompressed level was graded on a four-point scale using axial MRI to assess the adequacy of decompression. Late follow-up was conducted by telephone interview. RESULTS Laminectomy was performed at a mean 4.6 levels. Follow-up was obtained at a mean of 30.2 months after the procedure. The score on the modified Japanese Orthopedic Association scale improved in 97% of patients from a mean of 12.9 preoperatively to 15.58 postoperatively (P< 0.0001). In the upper extremities, function measured by the Cooper Scale improved from 1.8 to 0.7 (P< 0.0001), and in the lower extremities, function improved from 1.0 to 0.4 (P< 0.0002). There was a statistically significant improvement in strength in the triceps (P< 0.0001), iliopsoas (P< 0.0002), and hand intrinsic muscles (P< 0.0001). X-rays obtained at a mean of 5.9 months after surgery revealed no change in spinal alignment as measured by the curvature index. There was a decrease in the mean preoperative compression grade from 2.46 preoperatively to 0.16 postoperatively (P< 0.0001). There was no correlation between neurological outcome and the presence of spinal cord signal change on T2-weighted MRI scans, patient age, duration of symptoms, or preoperative medical comorbidity. CONCLUSION Multilevel laminectomy and instrumentation with lateral mass plates is associated with minimal morbidity, provides excellent decompression of the spinal cord (as visualized on MRI), produces immediate stability of the cervical spine, prevents kyphotic deformity, and precludes further development of spondylosis at fused levels. Neurological outcome is equal or superior to multilevel anterior procedures and prevents spinal deformity associated with laminoplasty or noninstrumented laminectomy.

Download Full-text

Case report of ervical myelopathy due to ossification of the posterior longitudinal ligament in association with flavum ligament ossification: MRI and CT appearance

Acta medica Lituanica ◽

10.6001/actamedica.v20i2.2696 ◽

2013 ◽

Vol 20 (2) ◽

pp. 79-83

Author(s):

Monique Boukobza ◽

Jurgita Ušinskienė ◽

Simona Letautienė

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Double Layer ◽

Spinal Canal ◽

Mixed Type ◽

Cervical Spinal Cord ◽

Asian Population ◽

Posterior Longitudinal Ligament ◽

Cord Compression ◽

Cord Injury

Background. Our objective is to analyze the cervical spinal cord damage and spinal canal stenosis due to OPLL which usually affects the cervical spine and leads to progressive myelopathy in 50–60s in Asian population; to demonstrate the mixed type OPLL and to show OPLL specific dural penetration signs: “double- layer” and “C-sign” on imaging. Materials and methods. Subacute cord compression developed over a 3-month period in a 43-year-old Japanese patient. Severe spinal canal narrowing was related to the mixed type OPLL at C3–C4 through C6–C7 associated to flavum ligament ossification at T3–T4. Lateral radiograph of the cervical spine showed intraspinal ossification, CT demonstrated specific dural penetration signs, and MRI disclosed spinal cord compression. Laminectomy at C3–C7 was performed and decompression of the spinal cord was confirmed by postoperative MRI. Conclusions. Absolute cervical stenosis and association with other diseases (like calcification of flavum ligament) predispose the patient to develop more severe deficit earlier in the clinical course. Specific CT signs, “double-layer” and “C-sign”, show dural involvement. MRI is a very useful modality to identify the precise level and extent of the spinal cord injury. OPLL must be included in the differential diagnosis of subacute cervical myelopathy.

Download Full-text

Proton magnetic resonance spectroscopy to evaluate spinal cord axonal injury in cervical spondylotic myelopathy

Journal of Neurosurgery Spine ◽

10.3171/2008.12.spine08367 ◽

2009 ◽

Vol 10 (3) ◽

pp. 194-200 ◽

Cited By ~ 51

Author(s):

Langston T. Holly ◽

Bonnie Freitas ◽

David L. McArthur ◽

Noriko Salamon

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Mr Spectroscopy ◽

Cervical Spondylotic Myelopathy ◽

Neuronal Loss ◽

Control Group ◽

Resonance Spectroscopy ◽

Cellular Biochemistry

Object Magnetic resonance spectroscopy is commonly used to provide cellular and metabolic information in the management of a variety of pathological processes that affect the brain, and its application recently has been expanded to the cervical spine. The majority of radiographic investigations into the pathophysiology of cervical spondylotic myelopathy (CSM) have been focused on the spinal cord macrostructure. The authors sought to determine the feasibility of using MR spectroscopy to analyze spinal cord biochemical function in patients with CSM. Methods Twenty-one patients with clinical and radiographic evidence of CSM were prospectively enrolled in this study. The patients underwent preoperative neurological examination, functional assessment, and cervical spine MR spectroscopy. Voxels were placed at the C-2 level, and the MR spectroscopy spectra peaks for N-acetylaspartate (NAA), choline, lactate (Lac), and creatine (Cr) were measured. Thirteen age-matched healthy volunteers served as controls. Results The NAA/Cr ratio was significantly lower in patients with CSM than in controls (1.27 vs 1.83, respectively, p < 0.0001). The choline/Cr ratio was not significantly different between the 2 groups. Seven of the patients with CSM had a Lac peak, whereas no peaks were noted in the control group (p < 0.05). There was no correlation between the severity of myelopathy and the NAA/Cr ratio in the CSM cohort. Conclusions Data in this study demonstrated the feasibility of using MR spectroscopy to evaluate the cellular biochemistry of the spinal cord in patients with CSM. Patients with CSM had a significantly lower NAA/Cr ratio than healthy controls, likely because of axonal and neuronal loss. The presence of Lac peaks in one-third of the patients in the CSM cohort further supports the role of ischemia in the pathophysiology of CSM.

Download Full-text