bluuebunny/crossref_metadata_2025 huggingface dataset:
fMRI May Help Resolve Incompatibility between Clinical and Conventional MRI Findings
Authors: Mak Kin Cheung , Li Xiang , Hu Yong , Luk Keith
Published: May 2015

Introduction

When assessing patients with cervical myelopathy, it is not uncommon to find patients with localizing signs that may not be entirely compatible with the 2D images seen on conventional MRI. Dynamic MRI films may add information, but with fMRI, specifically diffusion tensor imaging (DTI), more information regarding the microstructure of the tracts may be gleaned. Thus, this helps ensure that the diagnosis of cervical myelopathy is accurate and that the operation will be over the correct level(s).

Materials and Methods

A prospective case series in consecutive patients with cervical myelopathy was reviewed. The parameters looked at included multilevel compression, sidedness of compression, and detailed neurological assessment. T2-weighted (T2W) magnetic resonance imaging (MRI) and DTI were used to compare against a reference, the neurological findings. “Level diagnosis” and sidedness compatibility were then assessed.

Results

Weighted orientation entropy-based DTI analysis provided a closer match to the “level diagnosis.” Detailed DTI analysis also enabled reconciliation of neurological findings compared with conventional MRI. This was compared using simple anterior–posterior compression and high signal intensity (when available) as a means to identify level and determine clinical compatibility.

Conclusion

DTI has the potential of becoming a new standard for examining patients with cervical myelopathy, both in identifying diagnostic compatibility and the level most contributory to the neurological deficit. Further studies are required to further establish actual clinical usefulness of this modality.
Management of Acute Lumbar Back Pain: An Algorithm
Authors: Melcher Carolin , Wegener Bernd , Kanz Karl Georg , Jansson Volkmar , Birkenmaier Christof
Published: May 2015

Introduction

Low back pain imposes a considerable social and economic burden as one of the most serious public health issues in the developed nations and is one of the most common reasons for presentation to primary health-care providers, outpatient, or A&E departments. Currently, point prevalence of acute low back pain adds up to 40%, 1-year prevalence exceeds 70%, and life time prevalence equates 80%. Despite these certainties, the complex set of problems generating low back pain is still not satisfactorily understood. In addition, the complexity of diagnoses and treatment of lumbar pain syndrome provokes insecurity and restraint, especially in younger clinicians when faced with a patient suffering from acute back pain. To counter these problems—alleviating the operational sequences in A&Es, outpatient departments, and health-care centers and minimizing the risk of mis- or underdiagnosis of life-threatening internistic disease patterns, respectively, spinal emergencies—this algorithm has been originated.

Material and Methods

The algorithm is based upon the clinical guidelines of the national and international scientific associations in Europe, North America, and overseas as well as on experienced data in the daily work of the spine specialists at Ludwig-Maximilians-University Munich Campus Großhadern und Innenstadt. Hereby, consistency with the guidelines and recommendations of the literature, on one hand, and feasibility in the course of action in daily life with as much practical relevance as possible, on the other hand, were the main goals.

Results

In synopsis, an algorithm was formed which evaluates the crucial differential diagnosis of lumbar back pain according to their clinical relevance and targets a plot of action in reasonable diagnostic and therapeutic steps. By distinct yes–no decisions within the scope of history taken together with instructions according to clinical, laboratory, and radiological investigational steps, even clinicians without long-time experience in spine surgery should be able to handle patients with acute low back pain in any situation according to the guidelines and treatment needed.

Conclusion

The designated aim in developing this algorithm was to render assistance to colleagues of primary health-care providers, outpatient clinics, and A&E departments by reducing the complexity of diagnosis and treatment of lumbar pain. The aim was also to prevent mis- or underdiagnosis of life-threatening internistic disease patterns or possible spinal emergencies on one side and unnecessary diagnostic and therapeutical actions on the other side. An evaluation of practical application in daily routine will follow over time.
Study of Spine Rotator Muscles in Adolescent Idiopathic Scoliosis Patients
Authors: Wajchenberg Marcelo , Eulalio Martins Delio , Paiva Luciano Rafael , Del Curto David , Barros Puertas Eduardo , Schmidt Beny , Souza Bulle Oliveira Acary
Published: May 2015

Introduction

Several studies have presented morphological, biochemical, and histopathological changes in the paraspinal skeletal muscle of patients with adolescent idiopathic scoliosis (AIS). Some abnormalities, such as an increased amount of type I fibers in the concavity and the decreased number of type II in the convexity, an increase in the intracellular concentration of glycogen and lipids, structural changes in the sarcolemma and myotendinous junction, changes in the activity muscle enzyme, and an increase in intracellular calcium concentration, have been demonstrated. The aim of this article is to evaluate the rotator muscle fibers at the apical vertebra of curves of patients with AIS by histological and immunohistochemical analysis.

Materials and Methods

Twenty-one patients with AIS submitted to surgical correction between 2010 and 2013 had the spinal rotator muscles biopsied in the concavity and convexity of the apical vertebra of the thoracic curve during the surgery. Serial cryosections were stained with hematoxylin and eosin (HE), Sudan Red, NADH, ATPase, and Cytochrome oxidase. We evaluated muscle atrophy and hypertrophy, fatty proliferation, presence of endomysial and perimysial fibrosis, presence of hyaline fibers, mitochondrial proliferation, muscle necrosis, nuclear centralization, and inflammation. Two independent observers evaluated the sections.

Results

The average value of the angle of the main thoracic curve was 68 degrees Cobb. For analysis of nonparametric paired variables between the concave and convex sides, McNemar test was used with a significance level of 5%. The results of relative frequency and “ p” values showed significant differences in both endomysial and perimysial fibrosis and fatty involution when compared with both sides of the apical vertebra.

Conclusion

The paraspinal muscles at the apex of the deformity had a higher involvement in the concavity when analyzing the fatty involution and fibrosis. However, both sides showed signs of myopathy, muscle atrophy through areas of necrosis, presence of hyaline fibers, and mitochondrial proliferation.
Comparison of Shoulder Balance between Rod Derotation and Rod Derotation with Direct Vertebral Rotation in Double Thoracic Adolescent Idiopathic Scoliosis
Authors: Chang Dong-Gune , Kim Jin-Hyok , Ha Kee-Yong , Lim Dong-Ju , Suk Se-Il
Published: May 2015

Introduction

There is no report on the effect of DVR on the shoulder balance using segmental pedicle screw instrumentation in the treatment of double thoracic adolescent idiopathic scoliosis (AIS) with minimum 5-year follow-up. This study is to evaluate the shoulder balance resulting from the correction of double thoracic AIS comparing rod derotation (RD) with direct vertebral rotation (DVR) and RD only following pedicle screw instrumentations.

Materials and Methods

Double thoracic AIS patients ( n = 57) were treated by fusing both thoracic curves with RD and DVR ( n = 35), or RD ( n = 22) methods and retrospectively studied with a minimum 5 years follow-up.

Results

In the RD with DVR group, the preoperative PT curve of 40.2 degrees improved to 17.9 degrees postoperatively and 19.9 degrees at last follow-up. In the RD group, the preoperative PT curve of 37.5 degrees improved to 22.4 degrees postoperatively and 23.2 degrees at last follow-up. In the RD with DVR group, the preoperative DT curve of 56.6 degrees improved to 16.1 degrees postoperatively and 16.7 degrees at last follow-up. In the RD group, the preoperative DT curve of 50.6 degrees improved to 17.8 degrees postoperatively and 18.2 degrees at last follow-up. In the RD with DVR group, the average preoperative SHD of 16.3 mm was improved to 7.2 mm postoperatively and was 7.0 mm at last follow-up. In the RD group, the average preoperative SHD of 15.1 mm was changed to 7.5 mm postoperatively and was 7.3 mm at last follow-up.

Conclusion

Shoulder balance was not significantly improved even with additional correction method of DVR using segmental pedicle screw instrumentation in double thoracic AIS. The PT curve was rigid and corrected less in both groups. Therefore, less correction of the DT curve effectively achieves better shoulder balance.
Impact of Pedicle Screw Instrumentation with Addition of Crosslink on Growth of Spinal Canal in Young Children
Authors: Chen Zhong-Hui , Sun Xu , Wang Bin , Qian Bang-Ping , Yu Yang , Zhu Zezhang , Liu Zhen , Zhu Feng , Qiu Yong
Published: May 2015

Introduction

The use of pedicle screws has been popularized in the treatment of pediatric spinal deformity. Despite many studies regarding the effect of pedicle screws on the immature spine, there is a paucity of data concerning the impact of the screw-rod-crosslink complex on the development of spinal canal in young children. The objective of this study is to determine the influence of the screw-rod-crosslink complex on the development of spinal canal.

Materials and Methods

This study reviewed 34 patients with congenital scoliosis (14 boys and 20 girls) who were treated with posterior-only hemivertebrectomy and pedicle-screw-based short-segment instrumentation before the age of 5 years. They were followed-up for at least 24 months. Of these patients, 10 underwent only pedicle screw instrumentation without crosslink, and 24 with additional crosslink placement. The vertebrae were divided into three regions as follows: (1) S-CL (screw-crosslink) region, in which the vertebrae were inserted with bilateral pedicle screws and two rods connected with the crosslink; (2) S (screw) region, in which the vertebrae were inserted with bilateral pedicle screws but without crosslink; (3) NS (no screws) region, which comprised vertebrae cephalad or caudal to the instrumented region. The area, anteroposterior and transverse diameters of the spinal canal were measured at all vertebrae on the postoperative and last follow-up computed tomography axial images. The instrumentation-related parameters were also measured, including the distance between the bilateral screws and the screw base angle. The changes in the above measurements were compared between each region to evaluate the instrumentation's effect on the spinal canal growth.

Results

The mean age at surgery was 37 ± 11 months (range, 21–57 months) and the mean follow-up was 37 ± 13 months (range, 24–68 months). In each region, the spinal canal dimensions significantly increased during the follow-up period. There was no significant difference in the spinal canal growth rate between the S and NS regions or between the S-CL and NS regions. In addition, a comparison of the S-CL and S regions regarding the changes in measurements of the instrumentation construct revealed no significant differences.

Conclusion

Pedicle-screw-based instrumentation does not cause retardation of the development of spinal canal in young children. Moreover, use of the crosslink added to the screw-rod instrumentation also demonstrates no negative effect on the growth of the spinal canal. Thus, the addition of the crosslink to screw-based instrumentation is recommended to increase fixation stability in growing patients, even in very young pediatric population.
Natural Evolution of Syrinx in Patients Undergoing Posterior Correction for Scoliosis Secondary to Syringomyelia
Authors: Zhu Zezhang , Sha Shifu , Liu Zhen , Xie Dingding , Wang Bin , Sun Xu , Qian Bang-Ping , Zhu Feng , Yu Yang , Qiu Yong
Published: May 2015

Introduction

While correction surgery for syringomyelia-associated scoliosis frequently results in an elongation of the spine and may potentially influence the natural history of syringomyelia, a paucity of data exists regarding the syrinx behavior in the postoperative course. This study aims to investigate the natural evolution of syrinx in patients undergoing one-stage posterior instrumented spinal fusion for treatment of scoliosis secondary to idiopathic syringomyelia (IS).

Materials and Methods

Twenty-two patients with IS-associated scoliosis treated with one-stage posterior correction and fusion were evaluated at a minimum of 12-month follow-up (mean, 28.5 months; range, 12–57 months). Standing anteroposterior and lateral radiographs were examined for curve pattern, primary curve magnitude, thoracic kyphosis, and postoperative correction. Preoperatively and at follow-up, T2-weighted MR images, location, configuration, and size of the syrinx cavity were systematically assessed, and significant syrinx resolution was defined as more than 20% decrease in length or maximal syrinx/cord ratio.

Results

The series consisted of 15 male and 7 female patients with a mean age of 19.0 years (range, 12–35 years). Postoperative percent correction of the primary curve averaged to 64.0 ± 15.7% and was well maintained (58.5 ± 11.5%) at latest evaluation. Regarding syrinx size, the maximal syrinx/cord ratio improved from 0.44 to 0.41, with an average change rate of 3.5%. Overall, 10 (45.5%) and 11 (50.0%) patients met the criteria for syrinx improvement and stabilization, and syrinx deterioration was observed only in 1 case (4.5%). Age, gender, preoperative syrinx length, and number of fused vertebra were not associated with the prognosis of syringomyelia ( p > 0.05), whereas a significantly greater coronal correction was found in patients harboring a collapsed syrinx than in those with syrinx deterioration or stabilization (73.9 vs. 54.6%, p = 0.001). Using Spearman correlation test, improvement rate of the maximal syrinx/cord ratio was found to be strongly related to the coronal percent correction of the primary curve (r =  − 0.547, p = 0.008). There were no neurological or other major complications related to the surgery.

Conclusion

For treatment of scoliosis secondary to IS in the setting of minimal neurological deficits, one-stage spinal fusion with lengthening of the vertebral column provides an effective coronal and sagittal correction without neurological complications. Following surgery, the vast majority (95.5%) of syringes shrank or remained stable, indicating that deformity correction did not exert a deleterious effect on the natural evolution of syringomyelia.
Roentgenographic Evaluation of the Spine in Patients with Osteogenesis Imperfecta
Authors: Vaz de Lima Marcos , Santili Claudio , Akari Miguel
Published: May 2015

Background Context

Osteogenesis imperfecta (OI) is a hereditary connective tissue disorder that leads to bone weakness and deformities, especially in the spine, which can lead to poor outcomes.

Purpose

The aim of this study was to find patterns and risk factors in spinal deformities in patients with OI.

Study Design/Setting

Retrospective study at Irmandade da Santa Casa de Misericórdia de São Paulo.

Methods

Radiographs of the spine were evaluated.

Patient Sample

Seventy patients with OI were selected.

Outcome Measures

We observed the presence or absence of the following changes: biconcave vertebrae, chest and vertebral deformities, unilateral rib, and thoracolumbar kyphosis. The greater curve was considered to be the primary one and the secondary curve was considered compensatory.

Results

In the study sample, we observed that the patients' ages ranged between 7 and 50 years, with the mean age as 13 years, and 76% had scoliosis. In 68% of the cases, the main curve in the thoracic region was observed with the convexity to the right.

Conclusion

The following are associated with the presence of scoliosis in patients with OI: biconcave vertebrae, vertebral and chest deformity, unilateral rib, and thoracolumbar kyphosis. The thoracolumbar kyphosis is associated with thoracic hypokyphosis in patients with OI.
Classification of Degenerative Segment Disease in Adults with Deformity of the Lumbar or Thoracolumbar Spine
Authors: Berjano Pedro , Damilano Marco , Ismael Maryem , Cecchinato Riccardo , Lamartina Claudio
Published: May 2015

Introduction

Lumbar and thoracolumbar deformity in the adult is a condition with impairment of health status that can need surgical treatment. In contrast with adolescent deformity, where magnitude of the curve plays a significant role in surgical indication, the aspects relevant in adult deformity are pain and dysfunction that correlate with segment degeneration and imbalance. Previous classifications of adult deformity have been of little use for surgical planning.

Materials and Methods

Chart review and classification of radiographic and clinical findings. A classification of degenerative disc disease based on distribution of diseased segments and balance status of the spine is presented.

Results

Four main categories are presented: Type I (limited nonapical segment disease), Type II (limited apical segment disease), Type III (extended segment disease: apical and nonapical), and Type IV (imbalanced spine: IVa, sagittally imbalanced; IVb, sagittally and coronally imbalanced).

Conclusion

Types I and II can be treated by fusion of a selective area of the curve. Type III needs fusion of all the extension of the coronal curve. Type IV usually needs aggressive corrective procedures, frequently including posterior tricolumnar osteotomies. This classification permits interpreting the extension and magnitude of the disease and can help establish a surgical plan regarding selective fusion and methods of sagittal correction. Future research is needed to validate the classification.
New Implant Anchored Cage for Anterior Cervical Interbody Fusion
Authors: Lecaros Javier , Lecaros Miguel , Martínez Daniel , Fleiderman José , Urzúa Alejandro , Munjin Milán , Ilabaca Francisco , Ballesteros Vicente
Published: May 2015

Introduction

Currently, the anterior cervical discectomy and fusion (ACDF) is the “gold standard” treatment after anterior cervical decompression, in elderly patients or those who have contraindications for disc prosthesis. In this context, a new anchored implant with zero profile has been introduced for ACDF, which seeks to solve the problems that entail to add an anterior cervical plate and to obtain a higher level of stability to the segment, in comparison with cage only. The objective of this study is to describe the operative and postsurgical results, associated to the new zero-profile implant COALITION (Globus Medical, Inc, Audubon, Pennsylvania, United States), in patients who had surgery after cervical spine degenerative disease.

Materials and Methods

The data of 32 patients were reviewed by the Spine surgeons of Hospital del Trabajador (Santiago de Chile), between 2011 and 2014 under the ACDF technique using COALITION, in the context of cervical degenerative disease. The operative time, ambulation start, hospital stay, and dysphagia and dysphonia were measured.

Results

The patients had an average age of 51.64 ± 9.78 DE, on a male/female ratio of 16/15. A total of 53 levels were obtained (C3–C4: 3, C4–C5: 12, C5–C6: 20, and C6–C7: 18). The operative time was an average of 167.64 ± 50.28 minutes, using autologous iliac crest graft. The ambulation start time was 1 day (range, 1–2 days), with a hospital stay of 4 days (range, 2–7 days). The immediate dysphagia in postoperative was 56.25%, from this 77.77% was mild according to Bazaz score. Only 22.2% of the patients with immediate dysphagia persisted with a mild level, according to Bazaz score after 1 week of discharge from hospital. None of the patients presented chronicle dysphagia. Only four patients presented dysphonia symptoms that remitted spontaneously.

Conclusion

The new zero-profile implant demonstrated good postoperative results, with a low dysphagia and dysphonia prevalence, and these were completely resolved in all the cases.
Comparison of Allograft and Polyetheretherketone Cage in Anterior Cervical Discectomy and Fusion
Authors: Santos Edward Rainier , Yson Sharon , Sembrano Jonathan
Published: May 2015

Introduction

Structural allografts and PEEK cages are commonly used as interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome.

Methods

We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. All surgeries were performed by a fellowship-trained spine surgeon from November 2005 to September 2012. Immediate postoperative and 6-month lateral cervical radiographs were evaluated for subsidence by measuring the anterior disc height and posterior disc height at each operative level. Subsidence was defined as a decrease in anterior or posterior disc heights > 1 mm. The subsidence rate between the two groups was compared using the chi-square to test for significance (α = 0.05). NDI was recorded to evaluate the clinical outcome of the subsidence (SG) and nonsubsidence groups (NSG). t-test was used to test for difference between the two groups (α = 0.05).

Results

There was no statistically significant difference between subsidence rate of the PEEK group (54%; 46/685) and the allograft group (59%; 19/32) ( p = 0.69). Overall mean subsidence was 1.0 ± 1.3 mm anteriorly and 1.2 ± 1.2 mm posteriorly. The mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12 months) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13 months) for the NSG ( p = 0.74).

Conclusion

The subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF.
Comparison of Subsidence Rates of Large and Small Footprint Cages in Anterior Cervical Interbody Fusion
Authors: Sembrano Jonathan , Yson Sharon , Santos Edward Rainier
Published: May 2015

Introduction

Subsidence rates after ACDF have been reported widely in literature and range from 0 to 57%. Polyetheretherketone (PEEK) cages are one of the most commonly used interbody spacers. Although subsidence rates of different types of cages have been described, there are still no data on the effect of cage footprint size on subsidence. The primary aim of this study was to compare the subsidence rate between small and large footprint polyetheretherketone (PEEK) cages. The secondary aim was to determine if a correlation exists between subsidence and health outcome scores.

Methods

We performed a retrospective medical chart and radiographic review. Two fellowship-trained spine surgeons performed the surgeries from November 2008 to January 2013. Immediate postoperative and 6-month lateral cervical radiographs were evaluated for subsidence. Anterior and posterior disc heights at each operative level were measured. Subsidence was defined as a decrease in anterior or posterior disc height of > 1 mm. Cases were then designated to either the subsidence group (SG) or nonsubsidence group (NSG). Small footprint cage group (SF) consisted of PEEK cages measuring 14 × 11, 14 × 12, or 12.5 × 11.5 mm. Large footprint cage group (LF) consisted of cages measuring 15 × 13, 16 × 14, or 18 × 16 mm. Subsidence rates of the SF and LF groups were compared using chi-square test (α = 0.05). Preoperative and final (minimum 6 months) postoperative Neck Disability Index (NDI) scores of the SG and NSG were compared using t-test (α = 0.05).

Results

We reviewed 140 levels (71 cases*) of ACDF using small and large footprint PEEK cages. The small footprint group had 45 cases* (79 levels) and the small footprint group had 27 cases* (61 levels) with large footprint cages (* one case had both large and small footprint cages implanted on different levels) . There was a statistically significant difference between the subsidence rates of SF (54%; 43/79) and LF (30%; 18/61) ( p = 0.003). Fig. 1 breaks down the subsidence rate by cage size. Overall mean subsidence (SG) was 1.6 ± 1.1 mm anteriorly and 1.9 ± 1.1 mm posteriorly. Mean NDI improvement was 8.8 ± 23.2 mm (average follow-up: 13 months) for the SG and 22.9 ± 18.8 (average follow-up: 13 months) for the NSG ( p = 0.01).

Conclusion

Use of large footprint cages seems to have a protective effect against subsidence. Furthermore, cage subsidence > 1 mm results in less clinical improvement. [Figure: see text]
Management of Anterior Column Defects in Pyogenic Spondylodiscitis: A Systematic Review
Authors: Abdelrazek Mohamed , Robinson Yohan
Published: May 2015

Introduction

Study design: systematic review. Study Rationale: The surgical treatment of the anterior column defect in spondylodiscitis has been controversial for a long time and continues to remain so. Many techniques are described to manage the anterior column defect either through a posterior only method, anterior only method, or a combination of both. Many of the systematic reviews trying to investigate the best evidence for management involve tubercular and pyogenic, also all spinal column levels including cervical spine in their inclusion criteria regarding the differences in pathology, biomechanics, and natural history.

Objectives

The objective of the article is to present the difference in effectiveness and long-term reliability of all techniques which focus only on pyogenic infections in thoracolumbar segments.

Material and Methods

A systematic review of literature was performed using PubMed, ISI Web of Science, and Ovid Medline databases using the same search phrase: (anterior OR vertebral body OR defect) AND (spondylodiscitis OR discitis), further search was applied through reviewing references of the included search results. Articles were reviewed by the authors based on predetermined inclusion and exclusion criteria.

Results

PubMed search yielded 303 results, Ovid Medline yielded 451 results, and ISI Web of Science yielded 279 results. After title review and exclusion of duplication and non-English or German language articles, 32 articles were included and after final full text review 12 articles were included and presented. Three groups were formulated: anterior, posterior, and combined. Comparison included VAS, ODI, healing percentage, kyphosis correction and its maintenance, CRP, neurology, and complications.

Conclusion

There is a significant superiority of the combined anterior and posterior techniques in maintenance of kyphosis correction on the long-term follow-up, otherwise, due to the diversity of the criteria of evaluation of results in different articles, more clinical research should be directed to investigate the results of surgical management of anterior column defects in pyogenic thoracolumbar levels in particular.
Comparative Mechanical Properties of Commonly Used Spinal Rods
Authors: Melcher Carolin , Schröder Christian , Wegener Bernd , Jansson Volkmar , Birkenmaier Christof
Published: May 2015

Introduction

Pedicle-screw-rod constructs are used for a wide range of applications with strongly varying demands on construct stiffness. Rod stiffness is an important factor determining construct performance. A wide range of rod diameters and materials is available from manufacturers. No catalog has so far been published that would permit surgeons to objectively compare rods based on their specific properties. The goal of our study was to independently and objectively compare the biomechanical properties of spinal rods.

Material and Methods

Testing was according to ASTM norm F2193. We measured the bending stiffness, bending ultimate moment, bending yield moment, and elastic recoil. Over 200 tests were performed on 63 rods.

Results

We found decreasing material stiffness from cobalt–chrome (CoCr) and stainless steel (SS) via titanium (Ti) to PEEK. Surprising differences of up to 10% were found between Ti rods from different manufacturers. Differences between materials were most pronounced with small diameters: a 4.5 mm CoCr rod has about twice the stiffness of a 4.5 mm Ti rod, but the difference is only 15% with 6.0 mm rods. CoCr rods provided the highest elastic modulus with 4.5 mm diameter CoCr rods being as stiff as 5.5 mm diameter Ti rods and 5.5 mm CoCr rods being stiffer than 6.35 mm Ti rods. The stiffness of PEEK rods was only 4% that of Ti rods of the same diameter with the exception of carbon fiber-reinforced PEEK, which was close to titanium.

Conclusion

Our results show surprising variability between the popular 5.5 mm Ti rods from different manufacturers. With smaller diameters, the choice of material is increasingly important and may sometimes allow for using smaller implants while maintaining construct stiffness. Ultimate moment and yield moment determine the load at which a construct can be expected to plastically deform in vivo and what amount of force is required to contour the rod before implantation. The elastic recoil after plastic deformation makes exact contouring more difficult, which makes certain rods less comfortable to use in certain applications. We found considerable differences in the diameters/materials tested for all these parameters.
Biomechanical Effects of Cement Distribution in the Fractured Area on Symptomatic Osteoporotic Vertebral Compression Fractures: A Three-Dimensional Finite Element Analysis
Authors: Jiang Xiaobing , Ye Linqiang , Liang De , Zhang Shuncong
Published: May 2015

Introduction

According to some clinical studies, insufficient cement distribution in fractured area and asymmetrical cement distribution around fractured area were thought to be the reasons for unrelieved pain and recollapse after percutaneous vertebral augmentation (PVA) in the treatment of symptomatic osteoporotic vertebral compression fractures (OVCFs).

Materials and Methods

Finite element methods were utilized to investigate the biomechanical variance among three patterns of cement distributions (insufficient [ID] and sufficient [SD] cement distribution in the fractured area, asymmetrical cement distribution around the fractured area including upward [BU] and downward [BD] cement distribution).

Results

Compared with fractured vertebrae before PVA, distribution of von Mises stress in cancellous bone was transferred to be concentrated at cancellous bone surrounding cement after PVA, while it was not changed in cortical bone. Compared with SD group, maximum von Mises stress in cancellous bone and cortical bone and maximum displacement of augmented vertebrae increased significantly in ID group, while asymmetrical cement distribution around the fractured area in BU and BD groups mainly increased maximum von Mises stress in cancellous bone significantly. Similar results could be seen in all loading conditions.

Conclusion

Insufficient cement distribution in the fractured area may lead to unrelieved pain after PVA in the treatment of symptomatic OVCFs as maximum displacement of augmented vertebral body increased significantly. Both insufficient cement distribution in the fractured area and asymmetrical cement distribution around the fractured area are more likely to induce recollapse of augmented vertebrae because they increased maximum von Mises stress in cancellous bone and cortical bone of augmented vertebrae significantly.
A Systematic Review of Clinical Outcomes and Prognostic Factors for Patients Undergoing Surgery for Spinal Metastases Secondary to Breast Cancer
Authors: Sciubba Daniel , Yurter Alp , Ju Derek , Gokaslan Ziya , Fisher Charles , Rhines Laurence , Fehlings Michael , Fourney Daryl , Mendel Ehud , Laufer Ilya , Bettegowda Chetan , Goodwin C. Rory , Patel Shreyaskumar , Rampersaud Raja , Reynolds Jeremy , Chou Dean , Weber Michael , Clarke Michelle
Published: May 2015

Introduction

Surgical treatment and cement augmentation procedures are effective palliative techniques for the treatment of symptomatic spinal metastases. However, clinical results specific to a breast cancer cohort are generally lacking. We aim to systematically review the literature for clinical outcomes following operative interventions and prognostic factors for the treatment of breast metastases to the spine. Specifically, we describe the survival and clinical outcomes of surgery and cement augmentation procedures for breast metastases to the spine and to determine prognostic variables that may help recognize which patients will perform better or worse following surgery.

Methods

We performed a literature review using PubMed to identify articles that reported outcomes and/or prognostic factors of the breast cancer patient population with spinal metastases treated with any surgical technique since 1990.

Results

A total of 19 surgical studies, 4 cement augmentation studies, and 6 nonsurgical prognostic variable studies met the preset inclusion criteria. All but three studies (two surgical and one cement augmentation) were retrospective in nature, and all studies were of level of evidence IV. Median postoperative survival for metastatic breast cancer was 21.7 months (8.2–36 months), mean rate of pain improvement was 92.9% (76–100%), mean rate of neurological improvement was 63.8% (53–100%), mean rate neurological decline was 4.1% (0–8%), and mean rate LTC was 92.6% (89–100%). Kyphoplasty studies reported a high rate of pain control in selected patients. Negative prognostic variables included: hormonal (estrogen and progesterone) and HER2 receptor refractory tumor status, high degree of axillary lymph node involvement, and short disease-free interval (DFI). All other clinical or prognostic parameters were of low or insufficient strength.

Conclusion

With respect to clinical outcomes, studies consistently found that surgery resulted in neurological improvement for a majority of patients, with a minimal risk of worsening, and kyphoplasty studies reported a high rate of pain control. Increased postoperative survival 2002 onwards was likely due to FDA approval of new chemotherapies. However, specific factors associated with shorter survival following surgery involve hormone and HER2 receptor status and disease-free interval.
Evaluation of the Scoring System in Patients with Spinal Metastases from Nasopharyngeal Carcinoma
Authors: Kumar Naresh , Tan Jonathan , Zaw Aye Sandar
Published: May 2015

Background

The decision of operative treatment of patients with spinal metastases is dependent on the patient's predicted survival. The Tokuhashi, Tomita, Bauer, and Oswestry scores have been devised for survival prediction; however, none of these systems have been evaluated in nasopharyngeal carcinoma (NPC). We aimed to identify prognostic factors for survival, and investigate the predictive value of these scoring systems in predicting survival of the patients with spinal metastases from NPC.

Methods

We retrospectively evaluated the patients treated at our institution for spinal metastases from NPC. The predicted survival according to the four scoring systems (Tokuhashi, Tomita, Bauer, and Oswestry) was calculated and labeled as A scores. These patients were then rescored by assigning NPC as a good prognostic tumor and labeled as B scores. The predicted survival of scores A and B was compared with actual survival. Potential prognostic factors of survival were investigated using univariate and stepwise multivariate Cox regression analyses. Kaplan–Meier survival estimates, log-rank tests, and Cox regression analyses were done for all scoring systems A and B. The predictive values of each scoring system were calculated using post estimation after Cox regression analyses.

Results

Eighty-seven patients with spinal metastases from NPC were included in the study. The median overall survival for the whole cohort was 13 months (range: 1–120 months). In multivariate analysis, general condition ( p < 0.01), visceral metastases ( p < 0.01), and vertebral metastases ( p < 0.01) showed significant association with survival. The absolute score of all scoring systems was significantly associated with actual survival, which extended to the different prognostic subgroups of each scoring system. Log-rank test revealed that there were statistically significant differences in survival among the different prognostic groups of all scoring systems ( p < 0.01). Predictive value of survival by modified Tokuhashi score was the highest among all four scoring systems.

Conclusions

Patients with spinal metastases from NPC have good survival prognosis. All four scoring systems could be used to prognosticate these patients with a statistically significant association with actual survival. The modified Tokuhashi score is the best in doing so.
The Role of Intraoperative Neuromonitoring in Surgery of Lumbosacral Schwannomas: Five Years of Experience in a Single Center
Authors: Vukic Miroslav , Peterkovic Vjerislav , Nemir Jakob , Marasanov Sergej , Rozankovic Marjan , Tolic Tanja , Desnica Ana
Published: May 2015

Introduction

Lumbosacral schwannomas are predominantly benign tumors arising from nerves within the spinal canal. Being one of the most common intradural extramedullary tumors, spinal schwannomas comprise up to 30% of such lesions. Surgery is the primary treatment modality and after total resection recurrence is rare. We present our experiences and results with patients operated on lumbosacral schwannomas with the use of intraoperative neuromonitoring with evoked potentials (SSEP, MEP, muscle EMG, cauda mapping).

Materials and Methods

A retrospective review of prospectively collected data from patients with a diagnosis of lumbosacral schwannomas operated at University Hospital Centre Zagreb, Croatia, from January 2009 to May 2014 was performed. We analyzed preoperative and postoperative medical records, pathological findings, radiographic studies, and clinical outcome of patients treated surgically for lumbosacral schwannomas. Surgical outcome was compared with evoked potential changes during surgery for lumbosacral schwannoma that significantly differed from baseline values.

Results

In the analyzed period, 26 patients were operated on for lumbosacral schwannomas at our institution. Of these were 11 male and 15 female patients. Mean age was 49.8 years. There were 4 giant and 22 nongiant schwannomas. Giant spinal schwannoma was defined as a tumor that extends over two or more vertebral levels, erodes vertebral bodies, and/or extends into the extraspinal space disrupting myofascial planes. Low back pain and radiculopathy were the most common presenting symptoms, rarely associated with urinary incontinence. Nongiant schwannomas were treated using minimal invasive unilateral approach, while giant schwannomas were treated using laminoplasty technique. In all patients, intraoperative neuromonitoring with SSEP, MEP, and spontaneous EMG was performed. Postoperatively, 21 patients fully recovered from preoperative neurological symptoms at 6-month follow-up. In 12 patients, SSEP changes occurred during surgery that differ from baseline values but had no impact on outcome. Four patients had transient neurological worsening which was in concordance with intraoperative SSEP and EMG disturbance findings. Out of 26 tumors excised, 2 were malignant schwannomas. One of the patients with the diagnosis of malignant schwannoma had to be reoperated for recurrence and died 2 years later. One patient with giant schwannoma developed an intracranial epidural hematoma postoperatively.

Conclusion

Intraoperative multimodality (SSEP, EMG) monitoring properly used and understood is a useful tool in lumbosacral schwannoma surgery. It assists the surgeon through the procedure as a means of intraoperative guidance allowing for completeness and safety of tumor removal and as such can influence the surgical outcome.
Metastatic Spine Tumor: A 5-Year Review of Survival Rate with Tokuhashi Score
Authors: Kumar Renjit , Menon K. Sajesh , Ramachandara Krishnakumar , Abubakar Mohammed Kabir , Waheed Irshad Ahmed
Published: May 2015

Introduction

The ability to predict the outcome of surgical intervention in patients with metastatic spine tumor will help reduce unnecessary surgery in patients with advance disease, while encouraging surgery in patients who are likely to benefit. The Tokuhashi predictive score has provided a template that can be used to assess the suitability of treatment modality. The aim of the study is to compare outcomes of surgeries done with the Tokuhashi predictive score over a 5-year period at the Amrita Institute of Medical Sciences, Kochi, India, from January 1, 2007 to December 31, 2012.

Methods

Medical records of all patients who had diagnostic and/or therapeutic surgeries for metastatic spine tumor during the study period were retrieved and data were extracted and analyzed. Phone calls and letters were used to trace patients or their relations to ascertain whether the patients were alive or not on June 30, 2014.

Results

Data of 38 patients, 27 male and 11 female patients, were analyzed. Median age was 55 years. Unknown primary tumor accounts for the highest tumor (13), while carcinoma occurred in 24 patients (63.16%), making it the highest histological type. The Tokuhashi predictive scores are as follows: 0–8 (39.49%), 9–11 (52.63%), and 12–15 (7.89%). Nine patients (23.68%) were alive as on June 30, 2013.

Conclusions

Tokuhashi score is a reliable parameter for predicting outcome of life expectancies following surgery in patients with metastatic spine tumors. Tokuhashi score can be used to select the choice of treatment modalities in patients with metastatic spine tumors.
Surgery of Intradural Extramedullary Tumors
Authors: Donnarumma Pasquale , Nigro Lorenzo , Tarantino Roberto , Rullo Marika , Delfini Roberto
Published: May 2015

Introduction

Intradural extramedullary tumors (IDEMTs) are uncommon lesions causing pain and neurological deficits. The objective of this study is to evaluate the effects of surgery for IDEMTs analyzing a sample of 107 patients.

Materials and Methods

Cohort study recruiting all the patients operated for IDEMTs at the Department of Neurology and Psychiatry of “Sapienza” University, Rome, from January 2003 to January 2013. The analysis was conducted on the evaluation of clinical records over a 1-year follow-up. The graphic rating scale (GRS) was used for the assessment of pain. Neurological deficits were detected though neurological examination. The quality of life was evaluated with the EuroQol (EQ-5D). Statistical interpretation of the data was performed using SPSS v19 software (SPSS Inc, Chicago, Illinois, United States).

Results

A total of 107 patients were recruited. Three were lost to follow-up. Patients reported lower level of pain 1 year after surgery (presurgery = 6.05, postsurgery = 3.65). Mean comparison shows a significant decrease in Δ = −2.400 ( p < 0.001). A total of 92 patients (88.5%) were neurologically asymptomatic 1 year after surgery. Only 12 (11.5%) presented with a deficit, with a global decrease of 39% (chi-square 27.6, p < 0.005). The quality of life in patients operated for IDETMs was middle high (mean rating EQ-5D VAS 61.78%). The lowest levels of quality of life were found in patients with sphincter dysfunctions (mean = 33.4).

Conclusion

Surgery of IDEMTs has a good outcome. Patients reported lower levels of pain and a drastic reduction in neurological symptoms 1 year after surgery. The quality of life on an average is middle high. It is influenced mainly by the neurological outcome.
Anterior Extrapharyngeal Fixation of the Atlanto–Axial Joints
Authors: Patkar Sushil
Published: May 2015

Introduction

The atlanto–axial joints can be easily exposed from a unilateral submandibular extrapharyngeal approach. Decortication and intrajoint bone grafting can be easily accomplished. Rigid anterior fixation of the joint is possible without any risk to the vertebral arteries.

Materials and Methods

Between April 2008 and September 2014, 95 patients, 50 male and 45 female patients, in the age group of 12 to 82 years, were offered this procedure. 55 patients had anterior transarticular screws, 40 patients had anterior screw plate fixation (AAD 63 patients, tuberculosis 20, fixed AAD with Basilar invagination 12). All patients underwent preoperative dynamic X-rays of craniovertebral junction, computerized tomography (CT scan) of C1–C2 static and dynamic study with bone window settings and 3D reconstruction, magnetic resonance imaging (MRI), and MR angiography to study the course of vertebral artery. Stevenson technique (22 patients) for exposure to reach the prevertebral space at C1–C2. Technique 1: plate and screws (C1 lateral mass and C2 body); Technique 2: anterior transarticular screws across C1–C2 joint.

Results

Average procedure time was 3 hours, no case required blood transfusion, reoperation occurred in seven cases; three screw malposition both ipsilateral (right sided), reoperated within 48 hours and screw repositioned correctly. One overdistraction of C1–C2 joint due to screw not piercing the C1 lateral mass and pushing the lateral mass of C1 away from C2 (because of inadequate drilling of C1 lateral mass). Reoperated on the 3rd day and lateral mass of C1 drilled correctly and the screw passed successfully. Two inadequate excisions of odontoid process had to be removed transorally after 3 weeks because of excessive backward angulation of odontoid process. One case of screw loosening that was due to incorrect plate contouring, reoperation after 3 weeks when patient had come for first postoperative follow-up. Follow-up in 75% for 24 months. Rigid fixation in 100%, mortality 0%.

Conclusion

Anterior extrapharyngeal approach allows for reduction of the atlanto–axial dislocation, opportunity for bone grafting of the joint, and with anterior C1 lateral mass and C2 body screw plate fixation or anterior transarticular screws, provides rigid fixation without any risk to the vertebral artery, venous plexus, or spinal cord.
Treatment of Early-Onset Spinal Deformities, Complications
Authors: Legarreta Carlos , Rosito Gabriel , Maria Escalada , Reviriego Juan , Lutzky Lazaro , Krekun Walter , Medina Sebastian , Cirillo Juan , Tavolaro Trombetta Celeste
Published: May 2015

Introduction

Complications in the treatment of patients with early-onset deformities is a very common situation. When the surgeon assumes the treatment of this disease, he should try to gain control of the spinal deformity and obtain proper growth of thorax. The main goal of the treatment is to achieve these two aspects, with the lowest incidence of complications for the patient.

Patients and Methods

This is a retrospective study case series and the level of evidence is IV. We evaluated 13 patients treated with surgical techniques and growth distraction without fusion (MMC 5p, 2p idiopathic infantile scoliosis, spinal dysplasia 1p, 1p SCIWORA, Marfan syndrome 1p, 1p Escobar syndrome, Neurofibromatosis Type I 1p, 1p Thoracogenic scoliosis). The average age at the time of surgery was 4.10 years. The average preoperative angular value was 83.7 degrees (range, 50–135 degrees). We analyzed the following: (1) Risk factors preoperative; (2) Type of mounting; (3) Sequence of distractions; (4) Complications.

Results

Overall, 13 patients underwent 27 procedures of distraction. Analyzing each case, in particular, we have seen that the frequency of distractions averaged was a procedure each 11 months (range, 7–17 months), and 23% of these patients currently reached last surgery (spinal fusion) after 3.5 years of treatment with distractions (range, 2.10–3.10). In 13 patients, we observed complications in 69% during treatment. Our complications were as follows: (1) superficial infections 6.6%, (2) deep infections 10%, (3) rib fractures 10%, (4) spontaneous fusion 3.3%, and (5) prosthetic loosening.

Conclusions

In treatment of early onset deformities, the spinal surgeon should be prepared to deal different complications during treatment. On the basis of our experience, we consider it a high-risk pathology.