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Study design: Retrospective review of multicentric data. Objectives: The modified 5-item frailty index is a relatively new tool to assess the post-operative complication risks. It has been recently shown a good predictive value after posterior lumbar fusion. We aimed to compare the predictive value of the modified 5-item frailty index in cervical, thoracic and lumbar surgery. Methods: The American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) Database 2015-2020 was used to identify patients who underwent elective posterior cervical, thoracic, or lumbar fusion surgeries for degenerative conditions. The mFI-5 score was calculated based on the presence of 5 co-morbidities: congestive heart failure within 30 days prior to surgery, insulin-dependent or noninsulin-dependent diabetes mellitus, chronic obstructive pulmonary disease or pneumonia, partially dependent or totally dependent functional health status at time of surgery, and hypertension requiring medication. Multivariate analysis was used to assess the independent impact of increasing mFI-5 score on the postoperative morbidity while controlling for baseline clinical characteristics. Results: 53 252 patients were included with the mean age of 64.2 ± 7.2. 7946 suffered medical complications (14.9%), 1565 had surgical complications (2.9%), and 3385 were readmitted (6.3%), 363 died (.68%) within 30 days postoperative (6.3%). The mFI-5 items score was significantly associated with higher rates of complications, readmission, and mortality in cervical, thoracic, and lumbar posterior fusion surgery. Conclusion: The modified 5-item frailty score is a reliable tool to predict complications, readmission, and mortality in patients planned for elective posterior spinal fusion surgery. [ABSTRACT FROM AUTHOR]

Lateral lumbar interbody fusion (LLIF) is a popular technique as it allows for the placement of a large interbody implant through a retroperitoneal, transpsoas working corridor. Historically, the interbody is placed with the patient in lateral decubitus and then repositioned to prone for the posterior instrumentation. While this has been an effective and successful technique, removing the interoperative flip would improve the efficiency of these cases. This has led to modified LLIF approaches including single-position prone LLIF (pLLIF). This modification has shown to be an efficient and powerful technique; however, learning to navigate the LLIF approach in the prone position has its own challenges. The purpose of this article is to provide a detailed description of our pLLIF technique while simultaneously introducing surgical tips to overcome the challenges of the approach and optimize the implantation of the interbody device. Novel Techniques & Technology. [ABSTRACT FROM AUTHOR]

Study Design: Questionnaire-based survey. Objectives: Surgical site infection (SSI) is a common complication in spine surgery but universal guidelines for SSI prevention are lacking. The objectives of this study are to depict a global status quo on implemented prevention strategies in spine surgery, common themes of practice and determine key areas for future research. Methods: An 80-item survey was distributed among spine surgeons worldwide via email. The questionnaire was designed and approved by an International Consensus Group on spine SSI. Consensus was defined as more than 60% of participants agreeing to a specific prevention strategy. Results: Four hundred seventy-two surgeons participated in the survey. Screening for Staphylococcus aureus (SA) is not common, whereas preoperative decolonization is performed in almost half of all hospitals. Body mass index (BMI) was not important for surgery planning. In contrast, elevated HbA1c level and hypoalbuminemia were often considered as reasons to postpone surgery. Cefazoline is the common drug for antimicrobial prophylaxis. Alcohol-based chlorhexidine is mainly used for skin disinfection. Double-gloving, wound irrigation, and tissue-conserving surgical techniques are routine in the operating room (OR). Local antibiotic administration is not common. Wound closure techniques and postoperative wound dressing routines vary greatly between the participating institutions. Conclusions: With this study we provide an international overview on the heterogeneity of SSI prevention strategies in spine surgery. We demonstrated a large heterogeneity for pre-, peri- and postoperative measures to prevent SSI. Our data illustrated the need for developing universal guidelines and for testing areas of controversy in prospective clinical trials. Graphical Abstract [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional survey. Objectives: Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture. Methods: A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures. Results: There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%. Conclusions: Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures. [ABSTRACT FROM AUTHOR]

Study design: Systematic Review and Meta-analysis. Objective: Surgical alternatives to treat lumbar spinal stenosis and instability include indirect (ALIF, OLIF, and LLIF) and direct (TLIF or posterior lumbar interbody fusion) decompression and fusion interventions. Although both approaches have proven to be effective in reducing symptoms, it is unknown if there is any difference in effectiveness between them. In this systematic review and meta-analysis, we aimed to evaluate postoperative pain and disability in patients treated whit indirect vs direct decompression and fusion approaches. Methods: We conducted a systematic review of the literature consulting several databases and identified studies that enrolled patients diagnosed with degenerative lumbar spinal stenosis and instability treated with indirect or direct decompression and fusion techniques. Our primary endpoints were the visual analogue scale, Oswestry Disability Index, and the Japanese Orthopedics Association Back Pain Evaluation Questionnaire 1 year after the procedure. Secondary outcomes included complication rate, blood loss, and surgical time. Results: Nine retrospective and comparative studies were included enrolling a total of 1004 participants. Both surgical strategies had satisfactory clinical outcomes with no significant difference at 1 year. Although the complication rate was similar for both groups, the profile of the adverse events was different. In addition, patients treated with indirect decompression and fusion had significantly less blood loss and operative times. Conclusions: Indirect and direct decompression and fusion techniques are similarly effective in treating patients with lumbar spinal stenosis and instability. The ID group had significantly lower intraoperative blood loss and surgical time values. [ABSTRACT FROM AUTHOR]

Study Design: Multicentric retrospective study, Level of evidence III. Objective: The objective of this multicentric study was to analyze the prevalence and risk factors of early postoperative complications in adult spinal deformity patients treated with fusion. Additionally, we studied the impact of complications on unplanned readmission and hospital length of stay. Methods: Eight spine centers from 6 countries in Latin America were involved in this study. Patients with adult spinal deformity treated with fusion surgery from 2017 to 2019 were included. Baseline and surgical characteristics such as age, sex, comorbidities, smoking, number of levels fused, number of surgical approaches were analyzed. Postoperative complications at 30 days were recorded according to Clavien-Dindo and Glassman classifications. Results: 172 patients (120 females/52 males, mean age 59.4 ± 17.6) were included in our study. 78 patients suffered complications (45%) at 30 days, 43% of these complications were considered major. Unplanned readmission was observed in 35 patients (20,3%). Risk factors for complications were: Smoking, previous comorbidities, number of levels fused, two or more surgical approaches and excessive bleeding. Hospital length of stay in patients without and with complications was of 7.8 ± 13.7 and 17 ± 31.1 days, respectively (P 0.0001). Conclusion: The prevalence of early postoperative complications in adult spinal deformity patients treated with fusion was of 45% in our study with 20% of unplanned readmissions at 30 days. Presence of complications significantly increased hospital length of stay. [ABSTRACT FROM AUTHOR]

Background: Disseminated histoplasmosis involving the central nervous system occurs in 5-10% of cases. However, intramedullary spinal cord lesions are extremely rare. Here, 45-year-old female with a T8-9 intramedullary lesion did well following surgical extirpation. Case Description: For 2 weeks, a 45-year-old female experienced progressive lower back pain, paresthesias, and paraparesis. The magnetic resonance imaging showed an intramedullary expansive lesion at the T8-T9 level that markedly enhanced with contrast. Surgery, consisting of T8-T10 laminectomies performed using neuronavigation, an operating microscope, and intraoperative monitoring, revealed a well-demarcated lesion that proved to be a focus of histoplasmosis; it was readily completely excised. Conclusion: Surgery is the gold standard for treating spinal cord compression attributed to intramedullary histoplasmosis unresponsive to medical management. [ABSTRACT FROM AUTHOR]

There is a complicated relationship between land degradation, water efficiency, and crop yield in arid and semiarid regions. In the Semiarid Pampa region, Argentina, land use changes that affected fragile lands (high content of fine sands plus silt and low organic carbon) have decreased soil quality, thus endangering agricultural activities. The use of polyacrylamide (PAM) is an option for increasing productivity and protecting soil resources. However, there is scarce information about superabsorbent PAM on water storage linked to aggregate stability mechanisms in this fragile land. Hydrophysical variables and plant biomass were evaluated in a greenhouse pot experiment. Three factors were analyzed: 1) PAM rates (doses): D0 = 0%, D1 = 0.04%, and D2 = 0.08%; 2) vegetation presence (Festuca arundinacea ssp.): vegetation (+) and vegetation (–) and; 3) water regime: field capacity (FC) and half field capacity (FC/2). After 5 months, the incorporation of superabsorbent PAM had a strong effect on most hydrophysical variables. Storage variables (available water content and easily available water content) were improved mainly by increasing water retention at lower suctions (i.e. large pores). Dose increments regardless of the water regime led to higher plant biomass (P <.05). PAM incorporation enhanced abiotic mechanisms (swelling–shrinkage, cracks formation) and biotic mechanisms (root activity – direct, increment water retention – indirect) acting synergically to increase aggregate stability and water storage. Aggregate stability tests (fast wetting test – FW, slow wetting test – SW, and stirring aggregates after ethanol submersion – Stir) proved to be useful in discriminating stabilization mechanisms of soils, highlighting the effect of PAM incorporation on soil cohesion (Stir). Finally, superabsorbent PAM may contribute to maintain crop yields, leading to soil quality amelioration. [ABSTRACT FROM AUTHOR]

Background and Purpose: Anterior lumbar approaches are recommended for clinical conditions that require interbody stability, spinal deformity corrections or a large fusion area. Anterior lumbar interbody fusion in lateral decubitus position (LatALIF) has gained progressive interest in the last years. The study aims to describe the current habit, the perception of safety and the perceptions of need of vascular surgeons according to experienced spine surgeons by comparing LatALIF to the standard L5-S1 supine ALIF (SupALIF).Methods: A two-round Delphi method study was conducted to assess the consensus, within expert spine surgeons, regarding the perception of safety, the preoperative planning, the complications management and the need for vascular surgeons by performing anterior approaches (SupALIF vs LatALIF).Results: A total of 14 experts voluntary were involved in the survey. From 82 sentences voted in the first round, a consensus was reached for 38 items. This included the feasibility of safe LatALIF without systematic involvement of vascular surgeon for routine cases (while for revision cases the involvement of the vascular surgeon is an appropriate option) and the appropriateness of standard MRI to evaluate the accessibility of the vascular window. Thirteen sentences reached the final consensus in the second round, whereas no consensus was reached for the remaining 20 statements.Conclusions: The Delphi study collected the consensus on several points, such as the consolidated required experience on anterior approaches, the accurate study of vascular anatomy with MRI, the management of complications and the significant reduction of the surgical times of the LatALIF if compared to SupALIF in combined procedures. Furthermore, the study group agrees that LatALIF can be performed without the need for a vascular surgeon in routine cases. [ABSTRACT FROM AUTHOR]

Purpose: To describe a comprehensive setting of the different alternatives for performing a single position fusion surgery based on the opinion of leading surgeons in the field. Methods: Between April and May of 2021, a specifically designed two round survey was distributed by mail to a group of leaders in the field of Single Position Surgery (SPS). The questionnaire included a variety of domains which were focused on highlighting tips and recommendations regarding improving the efficiency of the performance of SPS. This includes operation room setting, positioning, use of technology, approach, retractors specific details, intraoperative neuromonitoring and tips for inserting percutaneous pedicle screws in the lateral position. It asked questions focused on Lateral Single Position Surgery (LSPS), Lateral ALIF (LA) and Prone Lateral Surgery (PLS). Strong agreement was defined as an agreement of more than 80% of surgeons for each specific question. The number of surgeries performed in SPS by each surgeon was used as an indirect element to aid in exhibiting the expertise of the surgeons being surveyed. Results: Twenty-four surgeons completed both rounds of the questionnaire. Moderate or strong agreement was found for more than 50% of the items. A definition for Single Position Surgery and a step-by-step recommendation workflow was built to create a better understanding of surgeons who are starting the learning curve in this technique. Conclusion: A recommendation of the setting for performing single position fusion surgery procedure (LSPS, LA and PLS) was developed based on a survey of leaders in the field. [ABSTRACT FROM AUTHOR]

Osteoporotic vertebral compression fractures of the thoracolumbar spine can progress to Kümmell's disease, an avascular vertebral osteonecrosis. Vertebral augmentation (VA)—vertebroplasty and/or kyphoplasty—is the main treatment modality, but additional short-segment fixation (SSF) has been recommended concomitant to VA. The aim is to compare clinical and radiological outcomes of VA + SSF versus VA alone. Systematic review, including comparative articles in Kümmell's disease, was performed. This study assessed the following outcome measurements: visual analog scale (VAS), Oswestry Disability Index (ODI), anterior vertebral height (AVH), local kyphotic angle (LKA), operative time, blood loss, length of stay, and cement leakage. Six retrospective studies were included, with 126 patients in the VA + SSF group and 152 in VA alone. Pooled analysis showed the following: VAS, non-significant difference favoring VA + SSF: MD –0.61, 95% CI (–1.44, 0.23), I2 91%, p = 0.15; ODI, non-significant difference favoring VA + SSF: MD –9.85, 95% CI (–19.63, –0.07), I2 96%, p = 0.05; AVH, VA + SSF had a non-significant difference over VA alone: MD –3.21 mm, 95% CI (–7.55, 1.14), I2 92%, p = 0.15; LKA, non-significant difference favoring VA + SSF: MD –0.85°, 95% CI (–5.10, 3.40), I2 95%, p = 0.70. There were higher operative time, blood loss, and hospital length of stay for VA + SSF (p < 0.05), but with lower cement leakage (p < 0.05). VA + SFF and VA alone are effective treatment modalities in Kümmell's disease. VA + SSF may provide superior long-term results in clinical and radiological outcomes but required a longer length of stay. [ABSTRACT FROM AUTHOR]

Purpose: Pola et al. described a clinical-radiological classification of pyogenic spinal infections (PSI) based on magnetic resonance imaging (MRI) features including vertebral destruction, soft tissue involvement, and epidural abscess, along with the neurological status. We performed an inter- and intra-observer agreement evaluation of this classification. Methods: Complete MRI studies of 80 patients with PSI were selected and classified using the scheme described by Pola et al. by seven evaluators. After a four-week interval, all cases were presented to the same assessors in a random sequence for repeat assessment. We used the weighted kappa statistics (wκ) to establish the inter- and intra-observer agreement. Results: The inter-observer agreement was substantial considering the main categories (wκ = 0.77; 0.71–0.82), but moderate considering the subtypes (wκ = 0.51; 0.45–0.58). The intra-observer agreement was substantial considering the main types (wκ = 0.65; 0.59–0.71), and moderate considering the subtypes (wκ = 0.58; 0.54–0.63). Conclusion: The agreement at the main type level indicates that this classification allows adequate communication and may be used in clinical practice; at the subtypes level, the agreement is only moderate. [ABSTRACT FROM AUTHOR]

Background: Preoperative optimization in patients undergoing posterior spinal fusion is essential to limit the number and severity of postoperative complications. Here, we, additionally, evaluated the impact of hypoalbuminemia on morbidity and mortality after posterior spinal fusion surgery. Methods: This retrospective analysis was performed using data from a prospective multicentric database (ACSNSQIP: 2015-2020) regarding patients undergoing posterior spinal fusions. Factors studied included; baseline demographics and 30-day postoperative complications (i.e., reoperations, readmissions, and mortality rates). Results: There were 6805 patients who met the inclusion criteria. They averaged 62 years of age and had an average BMI of 30.2. Within the 30-day postoperative period, 634 (9.3%) sustained complications; 467 (6.9%) were readmitted, 263 (3.9%) required reoperations, and 37 (0.5%) expired. Although multiple preoperative risk factors were analyzed, hypoalbuminemia, severe hypoalbuminemia, and dialysis were the strongest independent risk factors associated with complications (i.e., reoperations, readmissions, and mortality). Conclusion: Hypoalbuminemia, severe hypoalbuminemia, and dialysis were significant predictors for morbidity and mortality after posterior spinal fusion surgery. [ABSTRACT FROM AUTHOR]

Purpose: A classification system was recently developed by the international association AO Spine for assessing subaxial cervical spine fractures. Significant variability exists between users of the facet component, which consists of four morphological types (F1–F4). The primary aims of this study were to assess the diagnostic accuracy and reliability of this new system's facet injury morphological classifications. Methods: A survey consisting of 16 computed tomography (CT) scans of patients with cervical facet fractures was distributed to spine surgeon members of AO Spine Latin America. To provide a gold standard diagnosis for comparison, all 16 injuries had been classified previously by six co-authors and only were included after total consensus was achieved. Demographic and surgical practice characteristics of all respondents were analyzed, and diagnostic accuracy calculated. Inter- and intra-observer agreement rates were calculated across two survey rounds, conducted one month apart. Results: A total of 135 surgeons completed both surveys, among whom the mean age was 41.6 years (range 26–71), 130 (96.3%) were men, and 83 (61.5%) were orthopedic surgeons. The mean time in practice as a spine surgeon was 9.7 years (1–30). The overall diagnostic accuracy of all responses was 65.4%. Inter-observer and intra-observer agreement rates for F1/F2/F3/F4 were 55.4%/47.6%/64.0%/94.7% and 60.0%/49.1%/58.0%/93.0%, respectively. Conclusion: This study evaluates the AO Spine Classification System specifically for facet injuries involving the subaxial cervical spine in a large sample of spine surgeons. There was significant variability in diagnostic accuracy for F1 through F3-type fractures, whereas almost universal agreement was achieved for F4-type injuries. [ABSTRACT FROM AUTHOR]

Background: Our aim was to evaluate differences in neurosurgeons versus orthopedists access to technologies needed to perform minimally invasive spine surgeries (MISS) in Latin America. Methods: We sent a survey to members of AO Spine Latin America (January 2020), and assessed the following variables; nationality, level of hospital (primary, secondary, and tertiary), number of spinal operations performed per year, spinal pathologies addressed, the number of minimally invasive spine operations performed/year, and differences in access to MISS spinal technology between neurosurgeons and orthopedists. Results: Responses were returned from 306 (25.6) members of AO Spine Latin America representing 20 different countries; 57.8% of respondents were orthopedic surgeons and 42.4% had over 10 years of experience. Although both specialties reported a lack of access to most of the technologies, the main difference between the two was greater utilization/access of neurosurgeons to operating microscope (e.g., 84% of the neurosurgeons vs. 39% of orthopedic spine surgeons). Conclusion: Although both specialties have limited access to MISS spinal technologies, orthopedic spine surgeons reported significantly lower access to operating microscopes versus neurosurgeons (P < 0.01). [ABSTRACT FROM AUTHOR]

Background: Intraoperative neurophysiological monitoring (IOM) has become valuable in spine surgery. Unfortunately, it is not always available in many spine centers, especially in developing countries. Our aim was to evaluate the accessibility and barriers to IOM in spine surgery in Latin America. Methods: We designed a questionnaire to evaluate the characteristics of surgeons and their opinions on the usefulness of IOM for different spine operations. The survey was sent to 9616 members and registered users of AO Spine Latin America (AOSLA) from August 1, 2019, to August 21, 2019. Major variables studied included nationality, years of experience, specialty (orthopedics or neurosurgery), level of complexity of the hospital, number of spine surgeries performed per year by the spine surgeon, the types of spinal pathologies commonly managed, and how important IOM was to the individual surgeon. General questions to evaluate use included accessibility, limitations of IOM usage, management of IOM changes, and the legal value of IOM. The results were analyzed and compared between neurosurgeon and orthopedics, level of surgeon experience, and country of origin. Results: Questionnaires were answered by 200 members of AOSLA from 16 different countries. The most common responses were obtained from orthopedic surgeons (62%), those with more than 10 years of practice (54%); majority of surgeons performed more than 50 spine surgeries per year (69%) and treated mainly spine degenerative diseases (76%). Most surgeons think that IOM has a real importance during surgeries (92%) and not just a legal value. Although surgeons mostly considered IOM essential to scoliosis surgery in adolescents (70%), thoracolumbar kyphosis correction (68%), and intramedullary tumors (68%), access to IOM was limited to 57% for economic reasons. Of interest, in 64% of cases, where IOM was available and significant change occurred, the actual operative procedures were significantly altered. Conclusion: Despite the fact that 68% of spine surgeons believe IOM to be indispensable for complex spine surgery, cost remains the main barrier to its use/availability in Latin America. [ABSTRACT FROM AUTHOR]

Background: Intraoperative neurophysiological monitoring (IOM) has become valuable in spine surgery. Unfortunately, it is not always available in many spine centers, especially in developing countries. Our aim was to evaluate the accessibility and barriers to IOM in spine surgery in Latin America. Methods: We designed a questionnaire to evaluate the characteristics of surgeons and their opinions on the usefulness of IOM for different spine operations. The survey was sent to 9616 members and registered users of AO Spine Latin America (AOSLA) from August 1, 2019, to August 21, 2019. Major variables studied included nationality, years of experience, specialty (orthopedics or neurosurgery), level of complexity of the hospital, number of spine surgeries performed per year by the spine surgeon, the types of spinal pathologies commonly managed, and how important IOM was to the individual surgeon. General questions to evaluate use included accessibility, limitations of IOM usage, management of IOM changes, and the legal value of IOM. The results were analyzed and compared between neurosurgeon and orthopedics, level of surgeon experience, and country of origin. Results: Questionnaires were answered by 200 members of AOSLA from 16 different countries. The most common responses were obtained from orthopedic surgeons (62%), those with more than 10 years of practice (54%); majority of surgeons performed more than 50 spine surgeries per year (69%) and treated mainly spine degenerative diseases (76%). Most surgeons think that IOM has a real importance during surgeries (92%) and not just a legal value. Although surgeons mostly considered IOM essential to scoliosis surgery in adolescents (70%), thoracolumbar kyphosis correction (68%), and intramedullary tumors (68%), access to IOM was limited to 57% for economic reasons. Of interest, in 64% of cases, where IOM was available and significant change occurred, the actual operative procedures were significantly altered. Conclusion: Despite the fact that 68% of spine surgeons believe IOM to be indispensable for complex spine surgery, cost remains the main barrier to its use/availability in Latin America. [ABSTRACT FROM AUTHOR]

Background: The perception of major versus minor complications may vary according to surgeons, institutions, and different specialties. Here, we analyzed the geographic distribution of the different types/severities of the most frequent complications in spinal surgery, and assessed how the perception of spine surgeons about postoperative complications differed. Methods: We performed a cross-sectional study using a questionnaire, we developed to encompass different clinical scenarios of surgeons' perceptions of spine surgery complications. The survey involved the members of AOSpine Latin America (LA) (January 28, 2017-March 15, 2017). The main variables studied included: specialty, age, years of experience, country, individual surgeon's perception of different clinical scenarios, and the surgeon's classification of complications for each scenario (e.g., major, minor, or none). Our results from LA were then analyzed and compared to North American (NA) responses. Results: Orthopedic surgeons represented about 58.2% (n = 412) of the 708 questionnaires answered. Of interest, 45.6% (n = 323) of those responding had >10 years of experience. The countries analyzed included Brazil (31.5%), Mexico (17.5%), Argentina (14.4%), Colombia (8.0%), and Venezuela (7.6%). Four of the 11 scenarios showed consensus in the results (e.g., average being over 82.5%). A tendency toward consensus was present in 45.4% of the clinical cases, while two out of 11 clinical cases did not present a consensus among surgeons. Of interest, the perception of complications was similar between cohorts (LA 85% vs. NA 80%). Conclusion: Significant consensus in the perception of complications was observed in most of the analyzed scenarios for both LA and NA. However, within the LA data, responses to different clinical scenarios varied. [ABSTRACT FROM AUTHOR]

Background: The perception of major versus minor complications may vary according to surgeons, institutions, and different specialties. Here, we analyzed the geographic distribution of the different types/severities of the most frequent complications in spinal surgery, and assessed how the perception of spine surgeons about postoperative complications differed. Methods: We performed a cross-sectional study using a questionnaire, we developed to encompass different clinical scenarios of surgeons' perceptions of spine surgery complications. The survey involved the members of AOSpine Latin America (LA) (January 28, 2017-March 15, 2017). The main variables studied included: specialty, age, years of experience, country, individual surgeon's perception of different clinical scenarios, and the surgeon's classification of complications for each scenario (e.g., major, minor, or none). Our results from LA were then analyzed and compared to North American (NA) responses. Results: Orthopedic surgeons represented about 58.2% (n = 412) of the 708 questionnaires answered. Of interest, 45.6% (n = 323) of those responding had >10 years of experience. The countries analyzed included Brazil (31.5%), Mexico (17.5%), Argentina (14.4%), Colombia (8.0%), and Venezuela (7.6%). Four of the 11 scenarios showed consensus in the results (e.g., average being over 82.5%). A tendency toward consensus was present in 45.4% of the clinical cases, while two out of 11 clinical cases did not present a consensus among surgeons. Of interest, the perception of complications was similar between cohorts (LA 85% vs. NA 80%). Conclusion: Significant consensus in the perception of complications was observed in most of the analyzed scenarios for both LA and NA. However, within the LA data, responses to different clinical scenarios varied. [ABSTRACT FROM AUTHOR]

Copyright of Surgical Neurology International is the property of Scientific Scholar LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The paraspinal, posterolateral, or Wiltse approach is an old technique that observes the principles of an MIS procedure. The aim of this study was to provide a step-by-step description from the literature of the Wiltse paraspinal approach and analyze its main advantages and limitations. Methods: Here, we provide a step-by-step description of the Wiltse approach. Utilizing PubMed and Lilacs and the Mesh terms "Wiltse approach," "paraspinal approach," "muscle sparing approach," and "lumbar spine," we identified 10 papers. We then put together, based on these publications, a step-by-step analysis of the preparation, patient positioning, skin incision, fascial opening, dissection, bone identification, retractors, deperiostization, decompression, discectomy, instrumentation, arthrodesis, and closure for the Wiltse technique. Results: Most papers underscored the minimally invasive aspects of the typical Wiltse approach. Advantages included minimal intraoperative bleeding, a shorter hospital length of stay, and a low infection rate. Conclusion: The classical approach described by Wiltse is essentially minimally invasive, sparing both the muscle planes and soft tissues, allowing for ample far lateral lumbar decompression, including discectomy and fusion, with a low complication rate. [ABSTRACT FROM AUTHOR]

The increased use of by-products in finishing diets for cattle leads to diets that contain greater concentrations of crude protein (CP) and metabolizable protein (MP) than required. The hypothesis was that excess dietary CP and MP would increase maintenance energy requirements because of the energy costs of removing excess N as urea in urine. To evaluate the potential efficiency lost, two experiments were performed to determine the effects of feeding excess CP and MP to calves fed a finishing diet at 1 × maintenance energy intake (Exp. 1) and at 2 × maintenance intake (Exp. 2). In each experiment, eight crossbred Angus-based steers were assigned to two dietary treatments in a switchback design with three periods. Treatments were steam-flaked corn-based finishing diets with two dietary protein concentrations, 13.8% CP/9.63% MP (CON) or 19.5% CP/14.14% MP (dry matter basis; ECP), containing corn gluten meal to reflect a diet with excess CP and MP from corn by-products. Each period was 27 d in length with a 19-d dietary adaptation period in outdoor individual pens followed by a 4-d sample collection in one of four open circuit respiration chambers, 2-d fast in outdoor pen, and 2-d fast in one of four respiration chambers. Energy metabolism, diet digestibility, carbon (C) and nitrogen (N) balance, oxygen consumption, and carbon dioxide and methane production were measured. At both levels of intake, digestible energy as a proportion of gross energy (GE) tended to be greater (P < 0.06) in ECP than in CON steers. Metabolizable energy (ME) as a proportion of GE tended to be greater (P = 0.08) in the ECP steers than in the CON steers at 2 × maintenance intake. At 1 × and 2 × maintenance intake, urinary N excretion (g/d) was greater (P < 0.01) in the ECP steers than the CON steers. Heat production as a proportion of ME intake at 1 × maintenance tended (P = 0.06) to be greater for CON than for ECP (90.9% vs. 87.0% for CON and ECP, respectively); however, at 2 × maintenance energy intake, it was not different (63.9% vs. 63.8%, respectively). At 1 × maintenance intake, fasting heat production (FHP) was similar (P = 0.45) for both treatments, whereas at 2 × maintenance intake, FHP tended to be greater (P = 0.09) by 6% in ECP than in CON steers. Maintenance energy requirements estimated from linear and quadratic regression of energy retention on ME intake were 4% to 6% greater for ECP than for CON. Results of these studies suggest that feeding excess CP and MP from a protein source that is high in ruminally undegradable protein and low in protein quality will increase maintenance energy requirements of finishing steers. [ABSTRACT FROM AUTHOR]

Copyright of Surgical Neurology International is the property of Scientific Scholar LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Spine fractures may involve the ligamentum flavum (LF). Here, we utilized the "ligamentum flavum gap," defined by the discontinuity of the LF at the level of a vertebral fracture, to document a vertebral fracture. Methods: Utilizing X-rays, computed tomography (CT), and magnetic resonance (MR) studies, 10 patients with type B vertebral fractures were diagnosed with the ligamentum flavum gap (LFG: discontinuity of the LF) at the fracture levels. The fractures were located in 2 patients in the cervical and 8 in the thoracolumbar spine. Results: All 10 patients with vertebral fractures had complained of axial pain. Four also showed progressive thoracic kyphosis. Notably, all demonstrated a loss of continuity in the LF at the level of fracture "ligamentum flavum gap." T2-weighted and short tau inversion recovery (STIR) MR sagittal studies were best at locating LFG at the level of a fracture. Results: All 10 patients with vertebral fractures had complained of axial pain. Four also showed progressive thoracic kyphosis. Notably, all demonstrated a loss of continuity in the LF at the level of fracture "ligamentum flavum gap." T2-weighted and short tau inversion recovery (STIR) MR sagittal studies were best at locating LFG at the level of a fracture. [ABSTRACT FROM AUTHOR]

Background: The Gorham-Stout syndrome (GSS), also known as phantom bone disease, is a rare bone condition of unknown etiology. Involvement of the spine is described in <50 cases in the literature. Here, we report a case of thoracic spine fracture dislocation in a young female who was known to have GSS. Case Description: A 23-year-old female developed a left spontaneous hemothorax 10 years previously along with left ribs lytic lessions. Pleural and rib biopsies diagnosed angiomatosis and the clinical diagnosis of GSS was established. Following a minor trauma, she presented with a Frankel B deficit attributed to a T3-T4 fracture dislocation with severe spinal cord compression. The patient underwent halo traction with CT. Following reduction, decompression and C5 to T8 with instrumented fusion (posterior only), she neurologically improved to Frankel D, 2 years postoperatively. Conclusion: Although GSS is a rare condition in the spine, it may lead to gross instability and catastrophic vertebral fracture/dislocation with paraparesis. Acute spinal cord decompression with stabilization may be warranted to achieve neurological improvement. [ABSTRACT FROM AUTHOR]

Bichat Hospital's free and anonymous Voluntary Counseling and Testing centre in Paris is widely visited, with a high rate of HIV-positive diagnosis. This study proposed, in this centre, to describe the HIV newly-diagnosed patients over an 8-year period and to determinate risk factors for failure to return for a positive result. Higher risk for failure to return was found among the heterosexual subjects regardless of their socio-economic background. [ABSTRACT FROM AUTHOR]

Detection of high-order nonlinear components issued from microbubbles has emerged as a sensitive method for contrast agent imaging. Nevertheless, the detection of these high-frequency components, including the third, fourth, and fifth harmonics, remains challenging because of the lack of transducer sensitivity and bandwidth. In this context, we propose a new design of imaging transducer based on a simple fabrication process for high-frequency nonlinear imaging. The transducer is composed of two elements: the outer low-frequency (LF) element was centered at 4 MHz and used in transmit mode, whereas the inner high-frequency (HF) element centered at 14 MHz was used in receive mode. The center element was pad-printed using a lead zirconate titanate (PZT) paste. The outer element was molded using a commercial PZT, and curved porous unpoled PZT was used as backing. Each piezoelectric element was characterized to determine the electromechanical performance with thickness coupling factor around 45%. After the assembly of the two transducer elements, hydrophone measurements (electroacoustic responses and radiation patterns) were carried out and demonstrated a large bandwidth (70% at -3 dB) of the HF transducer. Finally, the transducer was evaluated for contrast agent imaging using contrast agent microbubbles. The results showed that harmonic components (up to the sixth harmonic) of the microbubbles were successfully detected. Moreover, images from a flow phantom were acquired and demonstrated the potential of the transducer for high-frequency nonlinear contrast imaging. [ABSTRACT FROM AUTHOR]

Background: Laparoendoscopic single-site (LESS) surgery has been established for various procedures. Shortcomings of LESS surgery include loss of triangulation, instrument collisions, and poor ergonomics, making advanced laparoscopic tasks especially challenging. We compared a LESS system with a robotic single-site surgery platform in performance of a suturing and knot-tying task under clinically simulated conditions. Methods: Each of five volunteer minimally invasive surgeons was tasked with suturing a 5 cm longitudinal enterotomy in porcine small intestine with square knots at either end, using a laparoendoscopic or da Vinci robotic single-site surgery platform, within a 20 min time limit. A saline leak test was then performed. Each surgeon performed the task twice using each system. The time to completion of the task and presence of a leak were noted. Fisher's exact test was used to compare the overall completion rate within the defined time limit, and a Wilcoxon rank test was used to compare the specific times to complete the task. A p value of <0.05 was considered significant. Results: All surgeons were able to complete the task on the first try within 20 min using the robot system; 60 % of surgeons were able to complete it after two attempts using the LESS surgery system. Time to completion using the robot system was significantly shorter than the time using the standard LESS system ( p < 0.0001). There were no leaks after closure with the robot system; the leak rate following the standard LESS system was 90 %. Conclusions: Surgeons demonstrated significantly better suturing and knot-tying capabilities using the robot single-site system compared to a standard LESS system. The robotic system has the potential to expand single-site surgery to more complex tasks. [ABSTRACT FROM AUTHOR]

Living cells sense the rigidity of their environment and adapt their activity to it. In particular, cells cultured on elastic substrates align their shape and their traction forces along the direction of highest stiffness and preferably migrate towards stiffer regions. Although numerous studies investigated the role of adhesion complexes in rigidity sensing, less is known about the specific contribution of acto-myosin based contractility. Here we used a custom-made single-cell technique to measure the traction force as well as the speed of shortening of isolated myoblasts deflecting microplates of variable stiffness. The rate of force generation increased with increasing stiffness and followed a Hill force-velocity relationship. Hence, cell response to stiffness was similar to muscle adaptation to load, reflecting the force-dependent kinetics of myosin binding to actin. These results reveal an unexpected mechanism of rigidity sensing, whereby the contractile acto-myosin units themselves can act as sensors. This mechanism may translate anisotropy in substrate rigidity into anisotropy in cytoskeletal tension, and could thus coordinate local activity of adhesion complexes and guide cell migration along rigidity gradients. [ABSTRACT FROM AUTHOR]

We developed a new versatile micron-scale rheometer allowing us to measure the creep or the relaxation function (time analysis), as well as to determine the dynamical complex modulus (frequency analysis) of a single living cell. In this setup, a microscopic sample can be stretched or compressed uniaxially between two parallel microplates: one rigid, the other flexible. The flexible microplate is used as a nanonewton force sensor of calibrated stiffness, the force being simply proportional to the plate deflection. An original design of the microplates allows us to achieve an efficient feedback control of either strain or stress applied to the cell. Controlling the flexible plate deflection with a typical precision of less than 200 nm, we are able to apply stresses ranging from a few pascals to thousands of pascals with a precision better than 2%. The control of the flexible plate deflexion is achieved by direct imaging of the plate tip on a photosensitive detector mounted on the phototube of an inverted microscope. Thus, the detection principle is suitable to all usual microscopes and very easy to set up. Beyond the creep function, already analyzed in detail in a previous work, we report here the first measurement of the relaxation function, as well as of the storage and the loss dynamic moduli [G′(f) and G″(f), f ranging from 0.02 to 10 Hz] for an isolated living cell. Eventually, the rheometer we built is not limited to cell stretching. It should also be a powerful tool to study the rheology of micron sized samples such as microgels or vesicles, as well as to perform shear experiments. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined the effects of implant strategy on the body weight of beef cattle. Methodology; Results; Discussion.

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) in captive and free-ranging cervids in the USA; its origin is obscure. Archival formalin-fixed and paraffin-embedded specimens of 16 captive mule deer brains with CWD were analyzed using immunocytochemistry for the disease-associated prion protein (PrP). The most prominent pattern of PrP deposition were plaque-like structures, a substantial proportion of which were florid plaques surrounded by a rim of spongiform vacuoles. The percentage of florid plaques was highly variable according to region, ranging from 0% to 52.7%. The highest percentage was observed in the medulla and basal ganglia, the lowest in the cerebral cortex. Only three brains contained no florid plaques. There were also punctate synaptic-type and perivascular deposits, particularly in areas of severe spongiform change, and subpial and subependymal plaque-like deposits, whereas cerebellar involvement was mild. Thus, CWD brain pathology prominently features florid PrP plaques, as does variant Creutzfeldt-Jakob disease (vCJD), but differs in other characteristics from vCJD. [ABSTRACT FROM AUTHOR]

Presents information on a study which evaluated and modified a mathematical model designed to predict individual feed required for the observed shrunk BW and ADG of growing cattle. Materials and methods; Results and discussion.

Presents information on a study which determined the effect of substituting bread by-product (BBy) for corn in a high-energy finishing diet on feedlot performance and beef quality. Methodology; Composition of feed ingredients; Apparent net energy value of BBy product and corn.