bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemotherapy-Related Hospitalization Among Community Cancer Center Patients
Authors: Hassett Michael J. , Rao Sowmya R. , Brozovic Suzana , Stahl James E. , Schwartz Joel H. , Maloney Betty , Jacobson Joseph O.
Published: February 2011

Learning Objectives

After completing this course, the reader will be able to: Define the potential risks of chemotherapy and evaluate the relationship between multiple comorbid conditions and the likelihood of experiencing these risks.Describe a process for tracking severe chemotherapy toxicity in a patient population, enumerate the barriers to implementation, and describe ways to overcome the barriers.

This article is available for continuing medical education credit at CME.TheOncologist.com

Purpose.

To describe the frequency, nature, trends, predictors, and outcomes of chemotherapy-related hospitalizations (CRHs) among a nonselected population of cancer patients treated at a community cancer center, and to explore the feasibility of implementing continuous quality improvement methodologies in routine oncology practice.

Methods.

We conducted a prospective cohort study of consecutive adult cancer patients who received chemotherapy at a community cancer center January 2003 to December 2006. Demographic, comorbidity, diagnosis, treatment, and laboratory data were collected via medical record abstraction. Hospitalizations were classified as chemotherapy related or unrelated by a multidisciplinary panel. Patients who experienced CRHs were compared with those who did not. Using a randomly sampled subset of cases and controls, we built a logistic regression model to identify independent predictors of CRH.

Results.

Of 2,068 chemotherapy recipients, 179 (8.7%) experienced 262 CRHs. Most hospitalizations were not chemotherapy related (73.7%). The mean monthly rate of CRH was 1.5%, the median length of stay was 5 days, the most common type of CRH was gastrointestinal (46.1%) followed by infectious (31.4%), and 0.9% of chemotherapy recipients had a fatal CRH. Significant predictors of CRH included having a comorbidity score of 3–4 versus 0 and having a higher creatinine level.

Conclusions.

Although the vast majority of chemotherapy recipients did not experience a CRH, these events were, unfortunately, not without serious consequences. Care should be taken when offering chemotherapy to patients with multiple comorbid conditions. Systematic efforts to monitor toxicity can lead directly to improvements in quality of care.
Modeling formation and control of disinfection byproducts in chlorinated drinking waters
Authors: McBean Edward , Zhu Zoe , Zeng Wen
Published: February 2011

While disinfection of drinking water reduces the risks of pathogenic infection, threats to human health due to the formation of disinfection byproducts (DBPs) may arise due to natural organic precursors. Regression-based models characterizing the formation of DBPs are derived from data for 28 conventional water treatment plants in Ontario. DBPs are shown to be correlated statistically with dissolved organic carbon, pre-and post-chlorination dosages, pH and temperature. Using backward elimination nonlinear regression, a set of mathematical functions are obtained (R2=0.62 to 0.79) for an array of DBPs. The models are used to guide decision-markers in the selection and operation of drinking water treatment processes to decrease DBP formation, indicating that a shift from emphasis on pre-chlorination to post-chlorination has the most effect on DBP formation.
Labor Attributes and Strategies: The Case of Tomato Workers in San Luis Potosi, México
Authors: Ledesma Maria Isabel Mora
Published: February 2011

In the context of the economic crisis in the 1980s that affected Mexico and the rest of Latin America, official policies encouraged commercial agriculture, especially the cultivation of export crops. During that period, women's entry into the paid labor market accelerated. For many women in rural areas, this meant widening opportunities for participation and a chance not only to help their families, but also to look for a partner, earn their own money, and “see the world.” This article analyzes the incorporation of women into the tomato agro-industry in the Altiplano region of el Valle de Arista, San Luis Potosí, Mexico. It discusses the strategies that women workers use—physical appearance, experience, and efficiency—as characteristics that are “required” in order to stay in this highly competitive, segmented, and precarious labor market.
Double Presence, Paid Work, and Domestic-Family Work
Authors: Moreno Neus , Moncada Salvador , Llorens Clara , Carrasquer Pilar
Published: February 2011

Double presence, which is understood as the need to respond simultaneously to the demands of paid and domestic-family work, mostly affects women and may negatively affect their health. Our hypothesis is that double presence increases as a function of the demands of domestic-family work, but is also associated with management practices related to the availability of time for paid work, prolonged and atypical work schedules, and heightened demands. A cross-sectional study was conducted with a representative sample of the salaried population in Spain. Information was gathered through a standardized questionnaire administered through home visits. Statistical analysis shows a relationship between double presence and the demands of increased work schedules, rotating schedules, irregular schedules, and exposure to psychosocial risks (high quantitative and emotional psychological demands). Double presence should be considered as a variable in the evaluation of psychosocial risks, and collective bargaining should consider negotiating clauses that can impact it positively.
Aliskiren in Combination with Losartan Reduces Albuminuria Independent of Baseline Blood Pressure in Patients with Type 2 Diabetes and Nephropathy
Authors: Persson Frederik , Lewis Julia B. , Lewis Edmund J. , Rossing Peter , Hollenberg Norman K. , Parving Hans-Henrik
Published: February 2011

Background and objectives

Elevated BP contributes to development and progression of proteinuria and decline in renal function in patients with type 2 diabetes. Our post hoc analysis assessed the baseline BP influence on the antiproteinuric effect in the Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) study.

Design, setting, participants, & measurements

In the AVOID study, 599 hypertensive type 2 diabetic patients with nephropathy received 6 months of aliskiren (150 mg force titrated to 300 mg daily after 3 months) or placebo added to losartan (100 mg) daily and optimal antihypertensive therapy. Changes in early morning urinary albumin:creatinine ratio and eGFR at week 24 were assessed by subgroups of baseline BP: Group A (prespecified target), <130/80 mmHg (n = 159); Group B, <140/90 mmHg but ≥130/80 mmHg (n = 189); and Group C (insufficient BP control), ≥140/90 mmHg (n = 251).

Results

Mean baseline BP (mmHg) levels for Groups A, B, and C were 120/71, 133/78, and 145/81, respectively. BP during the trial was nearly identical to baseline levels in all groups. The antiproteinuric effects of aliskiren were consistent across subgroups of baseline BP (19 to 22% reduction versus placebo). In Group C, the decline in eGFR was significantly lower with aliskiren than with placebo (P = 0.013).

Conclusions

Aliskiren (300 mg) added to losartan (100 mg) plus optimal antihypertensive therapy provides antiproteinuric effects independent of BP in patients with type 2 diabetes and nephropathy. Renal function was better preserved with aliskiren in patients with insufficient BP control.
On the spectral radius of cactuses with perfect matchings
Authors: Huang Ziwen , Deng Hanyuan , Simic Slobodan
Published: February 2011

Let C(2m, k) be the set of all cactuses on 2m vertices, k cycles, and with
perfect matchings. In this paper, we identify in C(2m, k) the unique graph
with the largest spectral radius.
Development of pediatric oncology
Authors: Dobanovacki Dusanka , Jokic Radoica , Vujosevic Bozica , Slavkovic Andjelka
Published: February 2011

The first publication about surgical treatment of tumors in children in medical literature dates from the beginning of the 19th century. Operations were a method of choice to treat. New development in science such as microscopy research, anesthesia, antisepsis, X-ray, and radium therapy has changed the approach to malignant diseases. The remarkable achievements in survival of oncology patients today are the results of a multimodal, multi-institutional, and multidisciplinary collaboration. Pediatric oncology differs from the oncology for adult patients in the type, generic considerations, diagnostics, and treatment approach. Many pediatric subspecialties are required to evaluate, treat, and manage children with malignant diseases, including provision of primary modalities and multiple supportive care services.
Waste reduction algorithm used as the case study of simulated bitumen production process
Authors: Savic Marina , Jovanovic Mica , Tanasijevic Jelena , Ocic Ozren , Spasic Aleksandar , Jovanic Predrag , Nikolic Ivan
Published: February 2011

Waste reduction algorithm - WAR is a tool helping process engineers for
environmental impact assessment. WAR algorithm is a methodology for
determining the potential environmental impact (PEI) of a chemical process.
In particular, the bitumen production process was analyzed following three
stages: a) atmospheric distillation unit, b) vacuum distillation unit, and c)
bitumen production unit. Study was developed for the middle sized oil
refinery with capacity of 5000000 tones of crude oil per year. Results
highlight the most vulnerable aspects of the environmental pollution that
arise during the manufacturing process of bitumen. The overall rates of PEI
leaving the system (PEI/h) - Iout PEI/h are: a) 2.14105, b) 7.17104 and c)
2.36103, respectively. The overall rates of PEI generated within the system -
Igen PEI/h are: a) 7.75104, b) -4.31104 and c) -4.32102, respectively.
Atmospheric distillation unit have the highest overall rate of PEI while the
bitumen production unit have the lowest overall rate of PEI. Comparison of
Iout PEI/h and Igen PEI/h values for the atmospheric distillation unit, shows
that the overall rate of PEI generated in the system is 36.21% of the overall
rate of PEI leaving the system. In the cases of vacuum distillation and
bitumen production units, the overall rate of PEI generated in system have
negative values, i.e. the overall rate of PEI leaving the system is reduced
at 60.11% (in the vacuum distillation unit) and at 18.30% (in the bitumen
production unit). Analysis of the obtained results for the overall rate of
PEI, expressed by weight of the product, confirms conclusions.
Influence of twisted tape turbulence promoter on fouling reduction in microfiltration of milk proteins
Authors: Popovic Svetlana , Jovicevic Dragica , Djuric Mirjana , Milanovic Spasenija , Tekic Miodrag
Published: February 2011

Membrane filtration has become one of the major technologies in the food
industry. It is widely applied in the dairy industry, and it is mostly used
for the concentration and fractionation of milk proteins and for the whey
processing. Of all pressure driven membrane processes, ultrafiltration is the
most widely used. The major disadvantage of pressure driven membrane
processes is severe fouling of membrane during filtration particularly when
the fluids containing proteins are processed. Fouling with proteins is
complex phenomenon because it occurs at the membrane surface as well as in
the pores of membrane, and depends on the operating conditions and on the
interactions of proteins and membrane material. In order to reduce fouling of
the membrane different techniques have been developed, and one of them relies
on the changing of the hydrodynamic conditions in the membrane or module. In
this study, influence of twisted tape turbulence promoters on the fouling
reduction in cross-flow microfiltration of skim milk was investigated.
Twisted tapes with tree characteristic ratios of helix element length to the
tape diameter (aspect ratio) were studied. It was shown that twisted tapes
with different aspect ratios reduce fouling of membrane by a factor of three
or more. The presence of twisted tape induces changes in the flow patterns
from straight to helicoidally thus producing turbulence flow at the lower
cross-flow rates. Turbulence intensification prevents accumulation of
proteins at membrane surface enabling reduction in reversible fouling what
results in the reduction of overall membrane fouling. The best performance
was achieved using a twisted tape with the lowest aspect ratio of 1.0. This
promoter reduces fouling seven times at low transmembrane pressure and low
cross-flow velocity. The twisted tape with aspect ratio 1.0 induces the most
intensive turbulence, the longest helicoidal flow path, and appearance of
vortices near the membrane surfaces, so the scouring of proteins from the
membrane surface is the most intensive in that case.
Surgical treatment of varicose vein using the tumescent technique of local anesthesia
Authors: Bjelanovic Zoran , Lekovic Ivan , Draskovic Miroljub , Misovic Sidor , Veljovic Milic
Published: February 2011

Background/Aim. Tumescent local anesthesia (TLA) is a technique for local and regional anesthesia of the skin and the subcutaneous tissue, using infiltration of large amounts of a diluted solution of local anesthetic. This technique is applied in plastic surgery, liposuction as well as in dermatology for the entire series of dermatocosmetic procedures. The purpose of this study was to determine efficiency of surgical treatment of varicose vein using TLA as an alternative method to a conventional treatment for varicose vein. Methods. Seventy-two patients with varicose vein were enrolled in the study. All of them were operated on applying TLA, from April 2008 to November 2009. TLA solution consisted of local anesthetics was used. TLA solutions used were: 1% prilocaine-chloride with adrenaline supplement, and 2% lidocaine-chloride and adrenaline in concentration of 0.1%-0.4%. Results. Out of 72 patients, we stripped great saphenous vein from 60 patient and did varicectomy as well as ligation of insufficiently perforating veins. In 12 patients we did partial varicectomy and ligation of perforating veins. There were not any patients with the need for continued surgery, as well as bringing patient to the general anesthesia due to pain during the surgery. One patient came for postoperative opening wound in the groin, one for infection of the wound and one for the formation of seroma in the groin. There were not any allergic reactions or systemic complications in the operations as well as postoperative period. Postoperatively, all the patients were treated with compressive elastic bandage during the period of 6 weeks as well as anticoagulation prophylaxis in the duration of 5 days. Conclusion. Surgery of varicose veins with implementation of TLA is easy and safe method with very low percentage of complications and unwanted effects. It is a good alternative method to classic surgery of varicose veins. The economic aspect is a very important component because the cost of this method is significantly lower than that of a classical surgical treatment of varicose veins.
Ovarian endometroid adenocarcinoma in pregnancy
Authors: Zivanovic Aleksandar , Dimitrijevic Aleksandra , Kastratovic Tatjana , Djuric Janko , Stankovic Vesna , Tanaskovic Irena
Published: February 2011

Background. Ovarian cancer is very rare in pregnancy. It is mainly of epithelial origin, low grade and low malignant potential. Case report. We presented a patient in which ultrasound confirmed the presence of clearly limited tumor in the left ovary when she was eight weeks pregnant. The results of 4D Color Doppler showed a central type of tumor vascularisation with resistance index (IR) less than 0.5. The Consultancy Board in Gynecology of the Institute for Oncology and Radiology of Serbia decided to remove the patient's left adnexa and intensively monitor the pregnancy period. The operation (Adnexectomia lateralis sinistra) was performed at 18th week of gestation. Histopathological analysis showed adenocarcinoma invasivum, endometroid well-differentiated type (histological grade I, nuclear grade 2). In 37th week of gestation, the patient gave birth to a male child by cesarean section. In the next 3 years the patient had no subjective interference, laboratory tests and ultrasonographic findings were normal. Conclusion. Ovarian cancer in pregnancy is usually asymptomatic and diagnosed during routine clinical and ultrasound examination. The color Doppler technique have particular importance in the diagnosis of pathological blood supply in tumors and in indication of malignant ovarian mass.
Depression in the Perinatal Period: Awareness, Attitudes and Knowledge in the Australian Population
Authors: Highet Nicole J. , Gemmill Alan W. , Milgrom Jeannette
Published: February 2011

Objective: To establish a benchmark of awareness, knowledge and attitudes in Australia in relation to depression and its treatment in the perinatal period, and to identify demographic factors associated with perinatal mental health literacy.

Method: A cross-sectional telephone survey (n = 1201) of a randomly selected sample of adults in each State and Territory of Australia, conducted in late 2009.

Results: Depression was the most frequently cited general health problem for women after childbirth (43.6% of spontaneous responses), in contrast to previous findings of low awareness of depression generally. A total of 94% of adults believed that postnatal depression requires specialized treatment. Older Australians (55 + years) identified postnatal depression less readily than younger Australians. Although well recognized as a specific mental health issue, as a general health issue antenatal depression had low recognition and was viewed by 52% of respondents as ‘normal’. Community beliefs about perinatal rates of depression appeared realistic. Men and women differed in their knowledge and beliefs about the symptoms and causes of postnatal depression. Difficulty in mother-infant bonding was seen as a common sign of postnatal depression, particularly by women. Most commonly, postnatal depression was perceived as having a biological rather than psychosocial etiology (30% of men, 41% of women). Recognition of anxiety in the postnatal period was relatively low, although higher among those with mental health training. Over 80% of Australians believed that all new mothers should be routinely assessed for depression.

Conclusions: Awareness of postnatal depression appeared to be at a high level in the community, but both anxiety and antenatal depression were comparatively under-recognized, suggesting there is considerable scope for awareness-raising. Established risk factors for postnatal depression were not coherently recognized. Ongoing tracking of perinatal mental health literacy in Australia is likely to be valuable in assessing the impact of future public awareness efforts.
Benchmarking Child and Adolescent Mental Health Organizations
Authors: Brann Peter , Walter Garry , Coombs Tim
Published: February 2011

Objective: This paper describes aspects of the child and adolescent benchmarking forums that were part of the National Mental Health Benchmarking Project (NMHBP). These forums enabled participating child and adolescent mental health organizations to benchmark themselves against each other, with a view to understanding variability in performance against a range of key performance indicators (KPIs).

Method: Six child and adolescent mental health organizations took part in the NMHBP. Representatives from these organizations attended eight benchmarking forums at which they documented their performance against relevant KPIs. They also undertook two special projects designed to help them understand the variation in performance on given KPIs.

Results: There was considerable inter-organization variability on many of the KPIs. Even within organizations, there was often substantial variability over time. The variability in indicator data raised many questions for participants. This challenged participants to better understand and describe their local processes, prompted them to collect additional data, and stimulated them to make organizational comparisons. These activities fed into a process of reflection about their performance.

Conclusions: Benchmarking has the potential to illuminate intra- and inter-organizational performance in the child and adolescent context.
Posterior transpedicular corpectomy and reconstruction of the axial vertebra for metastatic tumor
Authors: Ames Christopher P. , Wang Vincent Y. , Deviren Vedat , Vrionis Frank D.
Published: February 2011

Management of metastatic disease is a significant challenge in modern spinal surgery. Previously, radiation therapy alone was the most commonly employed treatment. Recent data, however, suggest that surgical decompression in addition to radiation therapy improves functional recovery compared with radiation therapy alone.

Metastatic disease most commonly affects the thoracic spine. Over the past decade surgical treatment has changed significantly for thoracic disease, shifting from transthoracic resection and reconstruction to single-stage posterolateral approaches that allow transpedicular resection and reconstruction. In posterolateral approaches, patients are spared the morbidity associated with transcavitary approaches while receiving the benefit of radical resection and circumferential reconstruction in a single-stage procedure.

The authors report 3 cases in which a similar posterior transpedicular technique, adapted for the cervical spine, was used for intralesional resection of metastatic tumors of the axis.
Shoulder balance after surgery in patients with Lenke Type 2 scoliosis corrected with the segmental pedicle screw technique
Authors: Li Ming , Gu Suxi , Ni Jianqiang , Fang Xiutong , Zhu Xiaodong , Zhang Zhiyu
Published: February 2011

Object

The authors evaluated the effectiveness of Lenke Type 2 criteria in scoliosis correction with the segmental pedicle screw (PS) technique, with emphasis on shoulder balance.

Methods

Twenty-five consecutive patients with Lenke Type 2 scoliosis (structural double thoracic curves, sidebending Cobb angle > 25°, or T2–5 kyphosis > 20°) who underwent segmental PS instrumentation were included in this study. At surgery, the patients were an average of 14.1 years of age, and the average duration of follow-up was 2.9 years. For radiological evaluation of the patients, preoperative, postoperative, and the latest available follow-up radiographs were used. The difference between right and left shoulder heights was determined to assess shoulder balance. All patients were treated with fusion of both the proximal and distal curves.

Results

The mean preoperative proximal thoracic curve of 43° was corrected to 21° postoperatively, a 51.2% correction. The preoperative lower thoracic curve of 61° was corrected to 23°, for a 62.3% correction. The preoperative shoulder height difference of −5.92 ± 12.52 mm (range: −31 to +14 mm, negative designating a lower left shoulder) was improved to 1.52 ± 8.12 mm. Postoperatively, no patient had significant or moderate shoulder imbalance, 4 patients had minimal shoulder imbalance, and 21 patients had balanced shoulders.

Conclusions

Although Lenke Type 2 criteria were developed wth Cotrel-Dubousset instrumentation, they are successfully applied to determining thoracic fusion when segmental PS instrumentation is used.
Spontaneous occlusion of a spinal arteriovenous malformation: is treatment always necessary?
Authors: Panciani Pier Paolo , Fontanella Marco , Crobeddu Emanuela , Schatlo Bawarjan , Bergui Mauro , Ducati Alessandro
Published: February 2011

Knowledge of spinal cord arteriovenous malformations (AVMs) has recently been improved by studies on pathophysiology, neuroimaging, and genetic data. Nevertheless, the natural history of these lesions remains poorly understood.

The authors present the case of an angiographic regression of a nidal-type spinal AVM at T-12 to L-1 in a 46-year-old woman with no risk factors. The natural course of untreated lesions is reviewed and discussed. To the best of the authors' knowledge, this is the first study that reports an angiographically proven complete spontaneous occlusion of a spinal AVM.
Application of a new hydrogel dural sealant that reduces epidural adhesion formation: evaluation in a large animal laminectomy model
Authors: Preul Mark C. , Campbell Patrick K. , Garlick David S. , Spetzler Robert F.
Published: February 2011

Object

The aim of this study was to evaluate the application and effects of a novel, nonswelling, polyethylene glycol-based hydrogel adhesion barrier and sealant in a canine laminectomy model of CSF leakage and adhesion formation.

Methods

After full-width L-2 and L-5 laminectomies, 1-cm midline durotomies were created and sutured closed, except for the last 1–2 mm on the cranial end to create spontaneous CSF leakage. All 5 control animals received no further treatment. Experimental animals received hydrogel at both durotomy sites via either the Dual Liquid applicator (5 animals) or MicroMyst gas-assisted sprayer (5 animals). Sealing of the CSF leak was confirmed by Valsalva maneuver. At 2 months, 2 animals from each group were killed to evaluate dural healing and epidural adhesion formation. The remaining animals were similarly evaluated 4 months after surgery. One animal died at 66 days due to a cause unrelated to hydrogel treatment.

Results

In hydrogel-treated animals, all leaking durotomies were sealed intraoperatively. All animals recovered uneventfully. There were no treatment-related health effects. MicroMyst hydrogel application was more controlled, slower, and significantly less thick (p = 0.0094) than Dual Liquid application. All 5 control animals developed subcutaneous CSF accumulations under the incision within days of surgery, compared with only 1 of 10 hydrogel-treated animals (p = 0.002). At 2 and 4 months, control laminectomy sites showed extensive, dense epidural adhesions blending with neodura, compared with hydrogel-treated sites (p < 0.0001 and p = 0.0234, respectively). At 2 months in hydrogel-treated animals, gel filled the epidural space and no epidural adhesions were noted (p < 0.0001 relative to controls). At 4 months, the hydrogel was absorbed. The hydrogel space was filled with scant, loosely organized connective tissue.

Conclusions

Hydrogel prevented CSF leakage and mitigated epidural scarring without affecting healing of the dura or laminectomy site. The safety profile of the hydrogel appears favorable due to its synthetic composition, polyethylene glycol chemistry, minimal local tissue response, and lack of neurological deficits. Controlled application of such hydrogel materials may reduce the incidence of postoperative leaks, prevent adhesion formation and thus improve recovery from spinal surgery, and improve identification of tissue planes for reoperations.
Comparison of thoracolumbosacral orthosis and no orthosis for the treatment of thoracolumbar burst fractures: interim analysis of a multicenter randomized clinical equivalence trial
Authors: Bailey Christopher S. , Dvorak Marcel F. , Thomas Kenneth C. , Boyd Michael C. , Paquett Scott , Kwon Brian K. , France John , Gurr Kevin R. , Bailey Stewart I. , Fisher Charles G.
Published: February 2011

Object

The authors compared the outcome of patients with thoracolumbar burst fractures treated with and without a thoracolumbosacral orthosis (TLSO).

Methods

As of June 2002, all consecutive patients satisfying the following inclusion criteria were considered eligible for this study: 1) the presence of an AO Classification Type A3 burst fractures between T-11 and L-3, 2) skeletal maturity and age < 60 years, 3) admission within 72 hours of injury, 4) initial kyphotic deformity < 35°, and 5) no neurological deficit. The study was designed as a multicenter prospective randomized clinical equivalence trial. The primary outcome measure was the score based on the Roland-Morris Disability Questionnaire assessed at 3 months postinjury. Secondary outcomes are assessed until 2 years of follow-up have been reached, and these domains included pain, functional outcome and generic health-related quality of life, sagittal alignment, length of hospital stay, and complications. Patients in whom no orthotic was used were encouraged to ambulate immediately following randomization, maintaining “neutral spinal alignment” for 8 weeks. The patients in the TLSO group began being weaned from the brace at 8 weeks over a 2-week period.

Results

Sixty-nine patients were followed to the primary outcome time point, and 47 were followed for up to 1 year. No significant difference was found between treatment groups for any outcome measure at any stage in the follow-up period. There were 4 failures requiring surgical intervention, 3 in the TLSO group and 1 in the non-TLSO group.

Conclusions

This interim analysis found equivalence between treatment with a TLSO and no orthosis for thoracolumbar AO Type A3 burst fractures. The influence of a brace on early pain control and function and on long-term 1- and 2-year outcomes remains to be determined. However, the authors contend that a thoracolumbar burst fracture, in exclusion of an associated posterior ligamentous complex injury, is inherently a very stable injury and may not require a brace.
Functional and clinical evaluation for the surgical treatment of degenerative stenosis of the lumbar spinal canal
Authors: Yaşar Bariş , Şimşek Serkan , Er Uygur , Yiğitkanli Kazim , Ekşioğlu Emel , Altuğ Tibet , Belen Deniz , Kars Zafer H. , Bavbek Murad
Published: February 2011

Object

This study was designed to evaluate the efficacy of decompressive surgery for degenerative lumbar spinal stenosis (LSS) on a functional and clinical basis.

Methods

A prospective analysis and follow-up of 125 consecutive patients with degenerative LSS between 2000 and 2006 were performed. All patients underwent surgery for lumbar stenosis. Functional evaluations of the patients were performed using a treadmill, the visual analog scale, and the Oswestry Disability Questionnaire (ODQ). These parameters were recorded before surgery and the 3rd month and 1st and 2nd years after treatment. The first symptom time (FST), maximal walking duration (MWD), and thecal sac cross-sectional area (CSA) before and after surgery were also recorded. Statistical relations between variables were calculated.

Results

As patient ages increased, the CSA of the thecal sac decreased. Decompressive surgery reached the target according to the difference between the preoperative and postoperative thecal sac CSA. A correlation between the CSA of the thecal sac and FST, and between the CSA of the thecal sac and MWD could not be established. There was a significant correlation between the FST and MWD, and a negative correlation could be established between the MWD and the ODQ score. Surgery led to significant decreases in the ODQ score. Maximal improvement was observed in the 3rd month after decompressive surgery.

Conclusions

The treatment for LSS should be decided using functional criteria; radiological criteria may not correlate with the severity of the disease. Improvements following lumbar decompression surgery continued within 1 year of treatment according to the ODQ and did not change significantly thereafter.
Electromyography in the detection of mechanically induced spinal motor tract injury: observations in diverse porcine models
Authors: Skinner Stanley A. , Transfeldt Ensor E.
Published: February 2011

Object

Porcine spinal cords were mechanically injured at the thoracic level while recording muscle-derived electrically stimulated transcranial motor evoked potentials (TcMEPs) and electromyography (EMG) readings from the same electrode derivations. The authors postulated that midthoracic spinal cord injury caused by diverse methods can trigger hindlimb EMG activity. Early detection of hindlimb EMG activity may permit avoidance of motor conduction block (TcMEP loss).

Methods

Twelve pigs underwent midthoracic spinal cord exposure. Spinal cord sectioning was performed to define dorsal column versus lateral spinal cord contribution to muscle-derived electrically stimulated spinal cord motor evoked potentials (SC MEPs) and TcMEPs (in 2 pigs). A bipolar needle stimulator was placed within intramedullary sites to 1) acquire electrically stimulated motor evoked potentials in the hindlimbs, and 2) induce mechanically stimulated hindlimb EMG activity at sites responsive to electrical stimulation (in 2 pigs). Transcranial MEPs and EMG recordings were observed during spinal cord distraction (in 3 pigs), slow and rapid extradural spinal cord compression with a metal caliper (in 3 pigs), and rapid extradural spinal cord compression with a spring-loaded clip (in 2 pigs).

Results

Lateral cord (but not dorsal column) sectioning abolished both SC MEPs and TcMEPs. Intramedullary electrical and mechanical stimulation within the lateral (but not dorsal) cord elicited ipsilateral hindlimb MEPs and EMG activity (“EMG injury discharge”), respectively. Distraction inconsistently produced EMG injury discharges concomitant with TcMEP loss. Rapid extradural spinal cord compression with a metal caliper or spring-loaded clip consistently induced EMG injury discharges (in 4 of 4 pigs); slow compression did not elicit EMG activity. Brief extradural spring-loaded clip compressions (1–2 seconds) elicited EMG injury discharges without TcMEP loss; 14-second clip compression effected EMG injury discharges and TcMEP loss, which recovered after clip removal.

Conclusions

Electromyographic activity (referred to as “EMG injury discharges” in the present study) can be elicited both by intramedullary manipulation and rapidly applied transaxial spinal cord compression. Preliminary observations suggest that these EMG injury discharges precede and may anticipate TcMEP loss. Presumably, rapid deformation of spinal motor tracts (which appear to lie within the lateral porcine spinal cord) generates descending volleys which can bring to firing threshold lumbar motor neurons (and recording of EMG injury discharges). Intraoperative neuromonitoring of high-risk spinal surgeries at the spinal cord level may benefit from the addition of EMG recording to tests of spinal cord motor conduction such as TcMEP. Further clinical trials are required to examine EMG efficacy in this context.
Epidural steroid injection resulting in epidural hematoma in a patient despite strict adherence to anticoagulation guidelines
Authors: Xu Risheng , Bydon Mohamad , Gokaslan Ziya L. , Wolinsky Jean-Paul , Witham Timothy F. , Bydon Ali
Published: February 2011

Epidural steroid injections are relatively safe procedures, although the risk of hemorrhagic complications in patients undergoing long-term anticoagulation therapy is higher. The American Society for Regional Anesthesia and Pain Medicine has specific guidelines for treatment of these patients when they undergo neuraxial anesthetic procedures. In this paper, the authors present a case in which the current American Society for Regional Anesthesia and Pain Medicine guidelines were strictly followed with respect to withholding and reintroducing warfarin and enoxaparin after an epidural steroid injection, but the patient nevertheless developed a spinal epidural hematoma requiring emergency surgical evacuation. The authors compare the case with the 8 other published cases of postinjection epidural hematomas in patients with coagulopathy, and the specific risk factors that may have contributed to the hemorrhagic complication in this patient is analyzed.
A remotely controlled model of spinal cord compression injury in mice: toward real-time analysis
Authors: Kouyoumdjian Pascal , Lonjon Nicolas , Prieto Monica , Haton Henri , Privat Alain , Asencio Gérard , Perrin Florence E. , Gaviria Manuel
Published: February 2011

Object

To date, there has been no efficient therapeutic approach to spinal cord injuries (SCIs). This may be attributable, at least in part, to difficulties in forming predictive and accurate experimental animal models. The authors' previous studies have identified 2 relevant conditions of such a model. The first condition is the ability to compare data derived from rat models of SCI by developing mouse models of SCI that permit access to a large range of transgenic models. The second condition is that the exploration of the consequences of each mechanism of spinal trauma requires modeling the different etiologic aspects of the injury.

Methods

To fulfill these 2 conditions a new model of mouse spinal cord compression injury was devised using a thread-driven olive-shaped compressive device. The authors characterized early motor, sensory, and histological outcomes using 3 olive diameters and different compression durations.

Results

A gradual and reproducible functional severity that correlated with lesion extension was demonstrated in 76 mice. To further substantiate the characterization of this model, a noncompetitive N-methyl-d-aspartate antagonist was administered in 30 mice, which demonstrated the involvement of excitotoxicity in this model.

Conclusions

The study demonstrated that spinal olive-compression injury in the mouse is a reproducible, well-characterized, and predictable model for analyzing early events after SCI. The nonmagnetic and remotely controlled design of this model will allow completion of the lesion while the animal is in the MR imaging apparatus, thus permitting further real-time MR imaging studies that will provide insights into the characterization of early events in the spatial and temporal evolution of SCI. Moreover, this model lays the foundation for future in vivo studies of functional and histological outcomes following SCI in genetically engineered animals.
Perforation of the right cardiac ventricular wall by polymethylmethacrylate after lumbar kyphoplasty
Authors: Farahvar Arash , Dubensky Deborah , Bakos Robert
Published: February 2011

The authors report the case of a 74-year-old woman who underwent an L-2 vertebral kyphoplasty. The patient experienced delayed postoperative hemodynamic deterioration that may have been caused by embolization of polymethylmethacrylate (PMMA) cement through the right cardiac ventricular wall. Cardiac and pulmonary embolization of bone cement can develop as a complication of vertebral kyphoplasty. Surgeons should be alert to this potentially life-threatening condition when performing this increasingly popular form of spine procedure.
Osteoinductive bone graft substitutes for lumbar fusion: a systematic review
Authors: Agarwal Rajender , Williams Kendal , Umscheid Craig A. , Welch William C.
Published: February 2011

Object

Autograft and allograft, the standard approaches for lumbar fusion procedures, have important disadvantages. Bone graft substitutes such as recombinant human bone morphogenetic proteins (rhBMP-2 and rhBMP-7) have emerged as viable alternatives. The authors conducted a systematic review to compare the efficacy and safety of osteoinductive bone graft substitutes using autografts and allografts in lumbar fusion.

Methods

A search for prospective controlled trials was conducted on MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases. Data were extracted for key outcomes including radiographically demonstrated nonunion, Oswestry Disability Index, operating time, blood loss, and length of hospital stay. The quality of randomized controlled trials was assessed using the Jadad scale. Meta-analyses were performed when feasible, and heterogeneity was assessed using the Q statistic and the I2 statistic.

Results

Seventeen of 732 potential studies met the inclusion criteria, with 9 examining rhBMP-2, 3 examining rhBMP-7, 3 examining demineralized bone matrix, and 2 examining autologous growth factor. Recombinant human BMP-2 significantly decreased radiographic nonunion when compared with autologous iliac crest bone graft (AIBG) in a meta-analysis (relative risk 0.27, 95% CI 0.16–0.46). Stratification of meta-analyses by the type of surgical procedure performed yielded similar results. Funnel plots suggested publication bias. Trials of rhBMP-2 suggested reductions in the operating time and surgical blood loss, with less effect on the length of hospital stay. There was no difference in radiographic nonunion with the use of rhBMP-7 when compared with AIBG (relative risk 1.02, 95% CI 0.52–1.98). Neither rhBMP-2 nor rhBMP-7 demonstrated a significant improvement on the Oswestry Disability Index when compared with AIBG. The limited data on demineralized bone matrix and autologous growth factor showed no significant improvement in radiographic outcomes.

Conclusions

Recombinant human BMP-2 may be an effective alternative to AIBG in lumbar fusion. Data are limited for other bone graft substitutes.
In vitro evaluation of a ball-and-socket cervical disc prosthesis with cranial geometric center
Authors: Barrey Cédric , Mosnier Thomas , Jund Jérôme , Perrin Gilles , Skalli Wafa
Published: February 2011

Object

Few biomechanical in vitro studies have reported the effects of disc replacement on motion and kinematics of the cervical spine. The purpose of this study was to analyze motion through 3D load-displacement curves before and after implantation of a ball-and-socket cervical disc prosthesis with cranial geometric center; special focus was placed on coupled motion, which is a well-known aspect of normal cervical spine kinematics.

Methods

Six human cervical spines were studied. There were 3 male and 3 female cadaveric specimens (mean age at death 68.5 ± 5 years [range 54–74 years]). The specimens were evaluated sequentially in 2 different conditions: first they were tested intact; then the spinal specimens were tested after implantation of a ball-and-socket cervical disc prosthesis, the Discocerv, at the C5–6 level. Pure moment loading was applied in flexion/extension, left and right axial rotation, and left and right lateral bending. All tests were performed under load control with a 3D measurement system.

Results

No differences were found to be statistically significant after comparison of range of motion between intact and instrumented spines for all loading conditions. The mean range of motion for intact spines was 10.3° in flexion/extension, 5.6° in lateral bending, and 5.4° in axial rotation; that for instrumented spines was 10.4, 5.2, and 4.8°, respectively. No statistical difference was observed for the neutral zone nor stiffness between intact and instrumented spines. Finally, the coupled motions were also preserved during axial rotation and lateral bending, with no significant difference before and after implantation.

Conclusions

This study demonstrated that, under specific testing conditions, a ball-and-socket joint with cranial geometrical center can restore motion in the 3 planes after discectomy in the cervical spine while maintaining physiological coupled motions during axial rotation and lateral bending.
Operative versus nonoperative management of acute odontoid Type II fractures: a meta-analysis
Authors: Nourbakhsh Ali , Shi Runhua , Vannemreddy Prasad , Nanda Anil
Published: February 2011

Object

The purpose of this study was to evaluate the feasibility of the criteria described in the literature as the indications for surgery for acute Type II odontoid fractures.

Methods

The authors searched the PubMed database for studies in which the fusion rate of acute Type II odontoid fractures following external immobilization (halo vest or collar) or surgery (posterior C1–2 fusion or anterior screw fixation) was reported. The only studies included reported the fusion rate for either 1) groups of patients whose age was either more or less than a certain age range (45–55 years); or 2) groups of patients with a fracture displacement of either more or less than a certain odontoid fracture displacement (4–6 mm) or the direction of displacement (see Methods section of text for more details). A meta-analysis in which the random effect model was used was conducted to analyze the data.

Results

There was a statistically significantly higher fusion rate for operative management compared with external immobilization (85 vs 60%, p = 0.01) for the patients > 45–55 years. However, the overall fusion rate was > 80% for the patients whose age was < 45–55 years, regardless of treatment modality, and no significant differences were observed between surgically and nonsurgically treated patients (89 and 81%, respectively; p = 0.29). The result of operation (overall fusion rate 89%) was superior to external immobilization (44%) when the fracture was posteriorly displaced (p < 0.001), but for anteriorly displaced fractures, the results of operative and nonoperative management were identical (p = 0.15). The overall fusion rate of operative management of both anteriorly and posteriorly displaced fractures proved to be > 85%, and no statistically significant difference was observed (p = 0.50). For all degrees of displacement (either > or < 4–6 mm) the operation proved to provide significantly better results than conservative treatment. The fusion rate of conservatively treated fractures with < 4–6 mm displacement was significantly better than in fractures with > 4–6 mm displacement (76 vs 41%, p = 0.002).

Conclusions

Operative treatment (posterior C1–2 fixation or anterior screw fixation) provides a better fusion rate than external immobilization for acute odontoid Type II fractures, although in certain situations, such as anterior displacement of the fracture and for younger (< 45–55 years of age) patients, conservative management (halo vest or collar immobilization) can be as effective as surgery. Operative management is recommended in older patients, in cases of posterior displacement of the fracture, and when there is displacement of > 4–6 mm.