Cervical Spine Deformity Research Articles

Impact of Cervical Spine Deformity on Preoperative Disease Severity and Postoperative Outcomes Following Fusion Surgery for Degenerative Cervical Myelopathy: Sub-analysis of AOSpine North America and International Studies.

Sub-analysis of the prospective AOSpine CSM North America and International studies. The aim of this study was to investigate the impact of cervical spine deformity on pre- and postoperative outcomes in fusion surgeries for degenerative cervical myelopathy. The associations between cervical alignment and patient outcomes have been reported but are not well established in a myelopathy cohort. The impact of deformity correction in this population also needs to be elucidated. A total of 757 patients were enrolled in two prospective international multicenter AOSpine studies. Among those who underwent anterior or posterior fusion surgeries, pre- and 1-year postoperative upright neutral lateral radiographs of cervical spine were investigated to measure C2-7 Cobb angle and C2-7 sagittal vertical axis (SVA). Patient outcome measures included the modified Japanese Orthopedic Association score for myelopathy severity, Neck Disability Index (NDI), and Short-form 36 (SF-36). These scores were compared between patients with and without cervical deformity, which was defined as C2-7 Cobb >10° kyphosis and/or SVA >40 mm. A total of 178 patients were included with complete pre- and postoperative radiographs. SVA significantly increased postoperatively (27.4 vs. 30.7 mm, P = 0.004). All outcome measurement showed significant improvements above minimal clinically important differences. 23.6% of the patients had cervical deformity preoperatively; preoperative deformity was associated with worse preoperative NDI scores (45.7 vs. 38.9, P = 0.04). Postoperatively, those with deformity exhibited significantly lower SF-36 physical component scores (37.2 vs. 41.4, P = 0.048). However, when focusing on the preoperatively deformed cohort, we did not find any significant differences in the postoperative outcome scores between those with and without residual deformity. There was a significant association between cervical deformity and both preoperative disease severity and postoperative outcomes; however, no impact of deformity correction was shown. 2.

Cervical Spine Deformity-Part 3: Posterior Techniques, Clinical Outcome, and Complications.

Cervical Spine Deformity-Part 3: Posterior Techniques, Clinical Outcome, and Complications.

Osteotomies in ankylosing spondylitis: where, how many, and how much?

This article presents the current concepts of correction of spinal deformity in ankylosing spondylitis (AS) patients. Untreated AS can be a debilitating disease. In a few patients, disease progression results in severe spinal deformity affecting not only the thoracolumbar, but also the cervical spine. Surgery for correction in AS patients has a long history. With the advent of modern instrumentation, standardization of surgical and anesthesiologic techniques, surgical safety and corrective results could be improved and experiences from lumbar osteotomies could be transferred to the cervical spine. This article presents the current concepts of correction of spinal deformity in AS patients. In particular, questions regarding the localization and number of osteotomies, the optimal surgical target angle as well as planning and prediction of postoperative alignment are discussed. Insight into recent technical developments, current challenges with correction and geometric analysis of center of rotation (COR) in cervical 3-column osteotomies (3CO) will be presented. The article should encourage readers to improve surgical correction efficacy and provide a better understanding of correction geometry in 3CO for thoracolumbar and cervical spinal deformities.

Cervical Spine Deformity-Part 3: Posterior Techniques, Clinical Outcome, and Complications.

The goals of cervical deformity surgery include deformity correction, restoration of horizontal gaze, decompression of neural elements, spinal stabilization with a biomechanically sound construct, and meticulous arthrodesis technique to prevent pseudoarthrosis and minimizing surgical complications. Many different surgical options exist, but selecting the correct approach that ensures the optimal clinical outcome can be challenging and often controversial. In this last part of the cervical deformity review series, various posterior deformity correction techniques are discussed in detail, along with an overview of surgical outcome and postoperative complications.

Assessment of a Novel Adult Cervical Deformity Frailty Index as a Component of Preoperative Risk Stratification.

To determine the value of a novel adult cervical deformity frailty index (CD-FI) in preoperative risk stratification. We reviewed a prospective, multicenter database of adults with cervical spine deformity. We selected 40 variables to construct the CD-FI using a validated method. Patients were categorized as not frail (NF) (<0.2), frail (0.2-0.4), or severely frail (SF) (>0.4) according to CD-FI score. We performed multivariate logistic regression to determine the relationships between CD-FI score and incidence of complications, length of hospital stay, and discharge disposition. Of 61 patients enrolled from 2009 to 2015 with at least 1 year of follow-up, the mean CD-FI score was 0.26 (range 0.25-0.59). Seventeen patients were categorized as NF, 34 as frail, and 10 as SF. The incidence of major complications increased with greater frailty, with a gamma correlation coefficient of 0.25 (asymptotic standard error, 0.22). The odds of having a major complication were greater for frail patients (odds ratio 4.4; 95% confidence interval 0.6-32) and SF patients (odds ratio 43; 95% confidence interval 2.7-684) compared with NF patients. Greater frailty was associated with a greater incidence of medical complications and had a gamma correlation coefficient of 0.30 (asymptotic standard error, 0.26). Surgical complications, discharge disposition, and length of hospital stay did not correlate significantly with frailty. Greater frailty was associated with greater risk of major complications for patients undergoing cervical spine deformity surgery. The CD-FI may be used to improve the accuracy of preoperative risk stratification and allow for adequate patient counseling.

P57 - Visualization of the Cervicothoracic Junction with EOS Imaging is Superior to Conventional Lateral Cervical Radiographs

BACKGROUND CONTEXT: The cervicothoracic junction plays an important role in the biomechanics of cervical spinal deformity but is typically a difficult area to visualize using traditional radiographs. Whole-body stereoradiography (EOS) allows for imaging of the entire axial skeleton in a weight-bearing position without parallax error and with lower radiation doses. EOS image quality has been shown to be superior to conventional radiographs (XR) for lateral spine imaging but can vary depending on the region of the body being imaged. To our knowledge, no prior study has evaluated the visibility of the cervicothoracic junction on EOS.

Cervical Spine Deformity-Part 2: Management Algorithm and Anterior Techniques.

A sound operative plan based on solid understanding of the pathology and biomechanics is the most important part of cervical deformity correction. Many different surgical options exist for operative management of cervical spine deformities. However, selecting the correct approach that ensures the optimal clinical outcome can be challenging and often controversial. In Part 2 of this three-part review series, we discuss the pre-operative planning, management algorithm, and anterior surgical techniques for cervical deformity correction.

POSTERIOR INSTRUMENTATION OF THE CERVICAL SPINE IN CHILDREN: LITERATURE REVIEW

The paper presents a review of the current literature on instrumental fixation of the pediatric cervical spine and technical features of the application of described techniques in children. The posterior instrumental fixation of the cervical spine provides stability and increases fusion rates in children with cervical spine deformities or instability, and allows intraoperative reduction of vertebral displacements. A number of morphological and clinical studies proved the possibility of implantation of modern metal constructs in children. Given the small size of bone structures in children, each case requires careful preoperative planning, proper intraoperative positioning and strict adherence to surgical techniques.

Principal Radiographic Characteristics for Cervical Spinal Deformity: A Health-related Quality-of-life Analysis.

Retrospective study. The aim of this study was to propose radiographic characteristics of patients with cervical disability and to investigate the relevant parameters when assessing cervical alignment. Although cervical kyphosis is traditionally recognized as presentation of cervical deformity, an increasing number of studies demonstrated that cervical kyphosis may not equal cervical deformity. Therefore, several other differentiating criteria for cervical deformity should be investigated and supported with quality of life scores. A database of full-body radiographs was retrospectively reviewed. Patients without previous cervical surgery, with a well-aligned thoracolumbar profile (defined as T1 pelvis angle <15°), and with an available Neck Disability Index (NDI) score were reviewed in this study. Subjects were stratified into an asymptomatic (64 subjects with NDI ≤15, Visual Analogue Scale [VAS] neck ≤3, and VAS arm ≤3) and a symptomatic group (107 subjects with NDI >15, VAS neck >3, or VAS arm >3). Independent t tests were performed to investigate differences between two groups. Logistic regressions and principal component analyses were then performed. NDI averaged 5.43 in asymptomatic group, significantly smaller than symptomatic group (5.43 vs. 41.25). t Test revealed that C2-C7 sagittal vertical axis (SVA), McGregor slope, and the slope of line of sight (SLS) were significantly different while C2-C7 angle (cervical curvature, CC) did not show statistical difference (P = 0.09). Logistic regressions were performed using the significantly different parameters as well as CC. Results identified C2-C7 SVA and SLS as independent risk factors for low health-related quality of life. The principal component analysis leads to a new factor (0.55 × C2C7SVA + 0.34 × COC2 + 0.77 × CC) with strong correlations with NDI, VAS, and EQ5D measurements. The traditional concept of cervical kyphosis should not be regarded as a standalone criterion of cervical deformity. The most clinically relevant components of cervical analysis are the C2-C7 SVA, C0C2 angle, and C2C7 angle. In addition, the three components should be assessed together in harmony and not individually. 4.

161 Direct Cost Analysis of 38 Cervical Spinal Deformity Operations Across Two Major Spinal Deformity Centers with Implications for Catastrophic Costs and 90-Day Cost Bundles

Abstract INTRODUCTION CMS has recently implemented 90-day cost bundles for joint replacement surgery, and taken steps to expand bundled payment programs. Our goal is to determine the 90-day costs associated with cervical spinal deformity cases across two major spinal deformity centers in order to guide the development of reasonable bundled payment plans. METHODS Retrospective evaluation of adults who underwent cervical deformity surgery 2013–2016 at two major spinal deformity centers (UCSF, Baylor). Inclusion criteria included adult patients with cervical kyphosis (C2-7 Cobb angle &gt;10°°) or cervical scoliosis (coronal Cobb able &gt;10°). Direct hospital costs for the index surgery and all visits within the first 90 days after surgery were determined from hospital billing data. Direct costs include surgical supplies/implants, room/care, pharmacy; they exclude indirect costs like overhead, administration, and utilities. RESULTS &gt;38 patients (25F, 13M; mean age = 60.4 ± 9.8 years) underwent fusions for cervical deformity. 29 procedures were posterior, 1 anterior, 7 anterior-posterior, and 1 posterior-anterior-posterior. Average number of levels fused was 9.3 ± 3.3. Average direct hospital cost for the 90-day period including surgery was $64,480 ± 23,816, and was similar between institutions ($62,569 versus $70,638). 4 of 38 patients (10.5%) were re-admitted within 90-days: re-admission costs constitute the majority of these patients' post-index surgery costs. 2 of 38 (5.3%) patients had catastrophic 90-day costs, greater than two standard deviations above the mean (&gt;$112,112). CONCLUSION The average 90-day direct hospital costs for patients undergoing cervical deformity surgery are $64,480. Readmissions and a greater number of operated levels contribute to higher costs; reasonable 90-day cost bundle plans must account for both of these issues. A limitation is that our analysis includes costs at our main hospital only; it does not include post-operative outpatient medications, physical therapy, rehabilitation, or admissions to outside hospitals. It is therefore imperative that further studies utilizing national databases are performed to understand the full scope of 90-day costs.

Surgical management of cervical spine deformity in chondrodysplasia punctata.

OBJECTIVE Chondrodysplasia punctata (CDP), a rare skeletal dysplasia, can lead to cervical spine instability and deformity. However, an optimal neurosurgical intervention has yet to be established. Thus, a retrospective study was conducted to assess the efficacy of various surgical interventions for children with CDP. METHODS The authors retrospectively reviewed 9 cases of CDP in which cervical decompression with or without posterior fusion was performed between April 2007 and May 2016. Patient demographics, preoperative clinical conditions, radiographic findings, surgical procedures, and the postoperative course were analyzed in detail. RESULTS A total of 12 operations were carried out in 9 patients (8 male, 1 female) during the study period. The patients' ages at the initial surgery ranged from 2 months to 2 years. Seven of the children had CDPX1, 1 had CDPX2, and 1 had tibia-metacarpal type CDP (CDP-TM). The lesion occurred at the craniovertebral junction (CVJ) in 7 cases and involved a subaxial deformity in 2 cases. The initial surgery was C-1 laminectomy with occipitocervical fusion (OCF) followed by halo external fixation in 5 cases, OCF alone in 1 case, and C-1 laminectomy alone in 3 cases. Three children required additional surgery. In one of these cases, a staged operation was required because the patient's head was too small to attach a halo ring at the time of the initial procedure (C-1 laminectomy). In another case, OCF was performed 11 months after C-1 laminectomy because of intramedullary signal change on serial MRI, although the child remained asymptomatic. In the third case, additional posterior fusion was performed 17 months after an initial laminectomy and OCF due to newly developed cervical dislocation caudal to the original fusion. This last patient required a third operation 9 months after the second because of deep wound infection. Surgery improved the motor function of all 7 children with CDPX1, but 3 children who had already suffered respiratory failure preoperatively required continued respiratory support. At the time of this report, 7 of the 9 children were alive and in stable condition. One child died due to restrictive respiratory insufficiency, and another died in an accident unrelated to CDP. CONCLUSIONS Surgical decompression with or without fusion for CVJ and subaxial cervical lesions in infants and toddlers with CDP generally saves lives and increases the likelihood of motor function recovery. However, in this case series the patients' preoperative condition had a strong effect on postoperative respiratory function. The surgery was not straightforward, and a second operation was required in some cases. Nevertheless, the findings indicate that early surgical intervention for CDP with cervical involvement is feasible, suggesting that the role of neurosurgery should be reevaluated.

Review of surgical correction of cervical kyphosis

Kyphotic deformity of the subaxial cervical spine can be debilitating to the patient, as well as challenging to the spine surgeon. Cervical kyphotic deformity is frequently progressive and can result in neurologic decline that mirrors the increase in deformity thus requiring surgical correction to alter the natural progression of the deformity. We review common etiologies, clinical and diagnostic workup, as well as pearls and pitfalls of each of the approaches to the cervical spine. Indications and contraindications for anterior, posterior, and combined approach are addressed.

Cervical Spine Deformity-Part 1: Biomechanics, Radiographic Parameters, and Classification.

Cervical spine deformities can have a significant negative impact on the quality of life by causing pain, myelopathy, radiculopathy, sensorimotor deficits, as well as inability to maintain horizontal gaze in severe cases. Many different surgical options exist for operative management of cervical spine deformities. However, selecting the correct approach that ensures the optimal clinical outcome can be challenging and is often controversial. We aim to provide an overview of cervical spine deformity in a 3-part series covering topics including the biomechanics, radiographic parameters, classification, treatment algorithms, surgical techniques, clinical outcome, and complication avoidance with a review of pertinent literature.

Cervical Spine Deformities in Children With Rhizomelic Chondrodysplasia Punctata.

Cervical spine deformity in rhizomelic chondrodysplasia punctata (RCDP) has been described with different findings reported in the literature. However, available literature provides limited data from a few cases with magnetic resonance imaging (MRI) of the cervical spine. Our report describes the MRI findings in a group of children with RCDP, aiming to reach a better understanding of this pathology. An Institutional Review Board-approved RCDP Registry was created at our institution with the goal of identifying pertinent medical issues over the lifespan of individuals with RCDP. Records of children within the registry were evaluated, and magnetic resonance images obtained between 2004 and 2015, were available for review. The levels of spinal canal stenosis were recorded and the severity of the stenosis was decided based on adults' parameters. Cord compression and myelomalacia were confirmed on the axial images. Sagittal lumbar spine magnetic resonance images were also evaluated when available, and the presence of tethered cord and fatty filum was recorded. Twenty-six children (15 boys and 11 girls) were identified in the RCDP Registry. Eleven children (6 boys and 5 girls) had sagittal MRI of the cervical spine available for review. Age at the time of MRI study was variable (1 wk to 32 mo). All patients except 1 had stenosis of the cervical spinal canal. Myelomalacia of the cord was noted only in this patient. This study suggests that, in children with RCDP, cervical spinal stenosis and cord compression are a real risk, and children with this diagnosis should have monitoring for these issues. Tethered cord is also a possible finding that needs to be evaluated. Full sagittal spine MRI is necessary to detect the possible deformities at the cervical and lumbar levels.

Cervical Spine Deformity in Long-Standing, Untreated Congenital Muscular Torticollis.

Congenital muscular torticollis (CMT) is a benign condition. With early diagnosis and appropriate management, it can be cured completely, leaving no residual deformity. However, long-standing, untreated CMT can lead to permanent craniofacial deformities and asymmetry. Four adult patients presented to the author with long-standing, untreated CMT. Initial clinical assessment demonstrated tightness of the sternocleidomastoid muscle on the affected side. Investigation of cervical spine using 3-dimensional computed tomography scans with cervical segmentation allowed a 3-dimensional module to be separately created for each vertebra to detect any anatomical changes. A change in the axis of the vertebral column was noted when compared to that of the skull. Also, there were apparent anatomical changes affecting the vertebrae, which were most noticeable at the level of the atlas and axis vertebrae. These changes decreased gradually till reaching the seventh cervical vertebra, which appeared to be normal in all patients. The changes in the atlas vertebra were mostly due to its intimate relation with the skull base. The changes of the axis were the most significant, affecting mainly the superior articular facet, the lamina, and the body. There were seemingly permanent changes along the cervical spine region in the adult patients with long-standing, untreated CMT in the form of bending and rotation deformities that might result in residual torticollis postoperatively.

Differential Activation of the Dorsal Neck Muscles During a Light Arm-Elevation Task in Patients With Chronic Nonspecific Neck Pain and Asymptomatic Controls: An Ultrasonographic Study

BackgroundDisturbance in neck muscle function is a well-known complication of chronic nonspecific neck pain (CNNP). It is, however, unclear which muscles are more susceptible to functional impairment in patients with CNNP during upper limb tasks. ObjectivesTo compare ultrasonographic changes in dorsal neck muscles thickness in patients with CNNP and asymptomatic controls while they performed a light load upper-limb movement. DesignCase control. SettingUniversity research laboratory. ParticipantsTwenty individuals with CNNP with a mean age of 23.35 ± 2.94 and 20 asymptomatic controls with a mean age of 22.30 ± 2.86, without any history of cervical diskopathy, fracture, trauma, inflammation, and spinal deformity were recruited for this study. MethodsUltrasonographic measurement of dorsal neck muscles thickness was performed during a light load 3-second arm-elevation task (shoulder scaption to 120°) in the 2 groups. Associations between pain intensity and patients’ perceived disability and between pain intensity and muscle thickness also were evaluated at the state of rest. Main Outcome MeasurementsThe thickness changes of the dorsal neck muscles throughout the arm elevation were calculated. The pain intensity and the patient’s perceived disability also were measured. ResultsA significant main effect of muscle activity status was revealed for the multifidus and semispinalis cervicis and the splenius capitis, indicating an increase in their thickness throughout the arm elevation (P < .001). The only muscle that showed a difference between groups was the multifidus (P = .007). Direct associations between pain and disability (r = .48, P = .03) and between pain and multifidus thickness (r = −.49, P = .03) also were observed. ConclusionThe deteriorating effect of CNNP on the neck muscles targets the deep layer of the dorsal neck muscles (ie, the multifidus) more than the superficial muscles during light upper-limb tasks. Level of EvidenceIII

204 - Characterizing Cervical Spine Deformity Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and following Treatment

BACKGROUND CONTEXT: Classification schemes for spine deformity provide a common language for communicating pathology and alignment. Cervical spine deformity (CSD) classifications are proposed but have not been implemented in a prospective CSD population, and in conjunction with adult spinal deformity (ASD) classifications.

P73 - Principal Radiographic Characteristics for Cervical Spinal Deformity: A Health-Related Quality of Life Analysis

P73 - Principal Radiographic Characteristics for Cervical Spinal Deformity: A Health-Related Quality of Life Analysis

202 - Predictive Model for Patient-Reported Outcomes Scores following Cervical Spine Deformity Surgical Correction

202 - Predictive Model for Patient-Reported Outcomes Scores following Cervical Spine Deformity Surgical Correction

Evolution of Cervical Spine Deformity Surgery and Ongoing Challenges

Evolution of Cervical Spine Deformity Surgery and Ongoing Challenges