Accuracy of imaging grading in comparison to open laminectomy to evaluate pedicle screws positioning.

Study design: Prospective experimental study. Objective: To compare the accuracy of O-Arm-acquired radiographic and computed tomography (CT) evaluation of thoracic pedicle screw placement with open laminectomy in a simulation laboratory. Summary of background data: Improving surgical safety and procedural efficiency during thoracic posterior spine instrumentation is essential for decreasing complication rates and possible related risks. The most common way of verifying the position of pedicle screws during the surgical procedure and immediately postoperatively is to acquire intraoperative fluoroscopic images and plain radiographs of the spine, respectively. Laboratory simulated surgery is a valuable tool to evaluate the accuracy of those exams. Methods: Twenty simulation models of scoliosis from T3 to T7 were instrumented by five spine fellows (total of 200 pedicle screws), followed by radiographic and CT images acquired with the assistance of the O-Arm which were evaluated by three independent raters. A fellowship-trained spine neurosurgeon performed laminectomies on the instrumented levels and assessed pedicle integrity (gold standard). Results: Forty-eight breaches were identified in the axial direct view after laminectomy. Of those, eighteen breaches were classified as unacceptable. Regarding the sagittal direct view, four breaches were observed, three of which were classified as unacceptable. Overall, both O-arm radiographic and CT evaluations had a significantly high negative predicted value but a low positive predicted value to identify unacceptable breaches, especially in the sagittal plane. The frequency of missed breaches by all three examiners was high, particularly in the sagittal plane. Conclusion: Postoperative evaluation of pedicle screws using O-arm-acquired radiographic or CT images may underdiagnose the presence of breaches. In our study, sagittal breaches were more difficult to diagnose than axial breaches. Although most breaches do not have clinical repercussions, this study suggests that this modality of postoperative radiographic assessment may be inaccurate. Level of evidence: 4.

How seasonality influences the thermal biology of lizards with different thermoregulatory strategies: a meta-analysis.

Ectotherms that maintain thermal balance in the face of varying climates should be able to colonise a wide range of habitats. In lizards, thermoregulation usually appears as a variety of behaviours that buffer external influences over physiology. Basking species rely on solar radiation to raise body temperatures and usually show high thermoregulatory precision. By contrast, species that do not bask are often constrained by climatic conditions in their habitats, thus having lower thermoregulatory precision. While much focus has been given to the effects of mean habitat temperatures, relatively less is known about how seasonality affects the thermal biology of lizards on a macroecological scale. Considering the current climate crisis, assessing how lizards cope with temporal variations in environmental temperature is essential to understand better how these organisms will fare under climate change. Activity body temperatures (Tb ) represent the internal temperature of an animal measured in nature during its active period (i.e. realised thermal niche), and preferred body temperatures (Tpref ) are those selected by an animal in a laboratory thermal gradient that lacks thermoregulatory costs (i.e. fundamental thermal niche). Both traits form the bulk of thermal ecology research and are often studied in the context of seasonality. In this study, we used a meta-analysis to test how environmental temperature seasonality influences the seasonal variation in the Tb and Tpref of lizards that differ in thermoregulatory strategy (basking versus non-basking). Based on 333 effect sizes from 137 species, we found that Tb varied over a greater magnitude than Tpref across seasons. Variations in Tb were not influenced by environmental temperature seasonality; however, body size and thermoregulatory strategy mediated Tb responses. Specifically, larger species were subjected to greater seasonal variations in Tb , and basking species endured greater seasonal variations in Tb compared to non-basking species. On the other hand, the seasonal variation in Tpref increased with environmental temperature seasonality regardless of body size. Thermoregulatory strategy also influenced Tpref , suggesting that behaviour has an important role in mediating Tpref responses to seasonal variations in the thermal landscape. After controlling for phylogenetic effects, we showed that Tb and Tpref varied significantly across lizard families. Taken together, our results support the notion that the relationship between thermal biology responses and climatic parameters can be taxon and trait dependent. Our results also showcase the importance of considering ecological and behavioural aspects in macroecological studies. We further highlight current systematic, geographical, and knowledge gaps in thermal ecology research. Our work should benefit those who aim to understand more fully how seasonality shapes thermal biology in lizards, ultimately contributing to the goal of elucidating the evolution of temperature-sensitive traits in ectotherms.

Computer aided diagnosis of neurodevelopmental disorders and genetic syndromes based on facial images - A systematic literature review.

Neurodevelopment disorders can result in facial dysmorphisms. Therefore, the analysis of facial images using image processing and machine learning techniques can help construct systems for diagnosing genetic syndromes and neurodevelopmental disorders. The systems offer faster and cost-effective alternatives for genotyping tests, particularly when dealing with large-scale applications. However, there are still challenges to overcome to ensure the accuracy and reliability of computer-aided diagnosis systems. This article presents a systematic review of such initiatives, including 55 articles. The main aspects used to develop these diagnostic systems were discussed, namely datasets - availability, type of image, size, ethnicities and syndromes - types of facial features, techniques used for normalization, dimensionality reduction and classification, deep learning, as well as a discussion related to the main gaps, challenges and opportunities.

Time to surgery for adolescent idiopathic scoliosis: How long does it take? A multicenter study.

Study design: Retrospective review of multicentric data. Objectives: To estimate the time from initial visit to surgery in adolescent idiopathic scoliosis (AIS) patients and the main reasons for the time to surgery in a multicenter study. Methods: This retrospective study evaluated 509 patients with AIS from 16 hospitals across six Latin American countries. From each hospital's deformity registry, the following patient data were extracted: demographics, main curve Cobb angle, Lenke Classification at the initial visit and time of surgery, time from indication-for-surgery to surgery, curve progression, Risser skeletal-maturity score and causes for surgical cancelation or delay. Surgeons were asked if they needed to change the original surgical plan due to curve progression. Data also were collected on each hospital's waiting list numbers and mean delay to AIS surgery. Results: 66.8% of the patients waited over six months and 33.9% over a year. Waiting time was not impacted by the patient's age when surgery first became indicated (p = 0.22) but waiting time did differ between countries (p < 0.001) and hospitals (p < 0.001). Longer time to surgery was significantly associated with increasing magnitude of the Cobb angle through the second year of waiting (p < 0.001). Reported causes for delay were hospital-related (48.4%), economic (47.3%), and logistic (4.2%). Oddly, waiting time for surgery did not correlate with the hospital's reported waiting-list lengths (p = 0.57). Conclusion: Prolonged waits for AIS surgery are common in Latin America, with rare exceptions. At most centers, patients wait over six months, most commonly for economic and hospital-related reasons. Whether this directly impacts surgical outcomes in Latin America still must be studied.

Environmental temperature predicts resting metabolic rates in tropidurinae lizards.

Interspecific variation in metabolic rates may be associated with climate, habitat structure, and resource availability. Despite a strong link between ecology and physiology, there is a dearth in the understanding of how the costs of body maintenance change during ecological transitions. We focused on an ecologically diverse group of neotropical lizards (Tropidurinae) to investigate whether and how resting metabolic rate (RMR) evolved under divergent micro- and macrohabitat conditions. Using a phylogenetic framework, we tested whether species from hot and dry habitats had lower RMRs in relation to those from cooler and mesic habitats, and investigated whether microhabitat usage had an effect over body mass-adjusted RMRs. Our results suggest that RMRs are not phylogenetically structured in Tropidurinae. We found no correlation between metabolism, precipitation, and microhabitat usage. Species from warmer habitats had lower RMR compared to those from cooler habitats, supporting a mechanism of negative compensation in metabolic responses to temperature. Ectotherms from warmer habitats can limit energetic demand and expenditure through reduced RMR, whereas those from cooler habitats may sustain activity despite thermal constraints via increased RMR. Our work highlights the role of temperature in shaping metabolic responses in lizards, giving additional support to the notion that physiology and ecological contexts are intertwined.

Are chromosome number and genome size associated with habit and environmental niche variables? Insights from the Neotropical orchids.

BACKGROUND AND AIMS: The entangled relationship of chromosome number and genome size with species distribution has been the subject of study for almost a century, but remains an open question due to previous ecological and phylogenetic knowledge constraints. To better address this subject, we used the clade Maxillariinae, a widely distributed and karyotypically known orchid group, as a model system to infer such relationships in a robust methodological framework. METHODS: Based on the literature and new data, we gathered the chromosome number and genome size for 93 and 64 species, respectively. We built a phylogenetic hypothesis and assessed the best macroevolutionary model for both genomic traits. Additionally, we collected together ecological data (preferences for bioclimatic variables, elevation and habit) used as explanatory variables in multivariate phylogenetic models explaining genomic traits. Finally, the impact of polyploidy was estimated by running the analyses with and without polyploids in the sample. KEY RESULTS: The association between genomic and ecological data varied depending on whether polyploids were considered or not. Without polyploids, chromosome number failed to present consistent associations with ecological variables. With polyploids, there was a tendency to waive epiphytism and colonize new habitats outside humid forests. The genome size showed association with ecological variables: without polyploids, genome increase was associated with flexible habits, with higher elevation and with drier summers; with polyploids, genome size increase was associated with colonizing drier environments. CONCLUSIONS: The chromosome number and genome size variations, essential but neglected traits in the ecological niche, are shaped in the Maxillariinae by both neutral and adaptive evolution. Both genomic traits are partially correlated to bioclimatic variables and elevation, even when controlling for phylogenetic constraints. While polyploidy was associated with shifts in the environmental niche, the genome size emerges as a central trait in orchid evolution by the association between small genome size and epiphytism, a key innovation to Neotropical orchid diversification.

A guide to incubate eggs of Tropidurus lizards under laboratory conditions.

Studies in Evo-Devo benefit from the use of a variety of organisms, as comparative approaches provide a better understanding of Biodiversity and Evolution. Standardized protocols to incubate eggs and manipulate embryo development enable postulation of additional species as suitable biological systems for research in the field. In the past decades, vertebrate lineages such as Squamata (lizards, snakes, and amphisbaenians) emerged as crucial study systems for addressing topics as diverse as phenotypic evolution and climate change. However, protocols for maintaining gravid females and incubating eggs in the lab under experimental conditions are available to only a few squamate species. This resource article presents a simple incubation guide that standardizes conditions to maintain embryos of Tropidurus catalanensis (Squamata: Tropiduridae) under different experimental conditions, manipulating relevant environmental factors like temperature and humidity. We identified associated effects relating the egg incubation condition to developmental stage, incubation time, hatching success, and resulting morphotypes. Temperature and humidity play a key role in development and require attention when establishing the experimental design. Current literature comprises information for Tropidurus lizards that ponders how general in Squamata are the ecomorphs originally described for Anolis. Studies evaluating phenotypic effects of developmental environments suggest plasticity in some of the traits that characterize the ecomorphological associations described for this family. We expect that this incubation guide encourages future studies using Tropidurus lizards to address Evo-Devo questions.

Unmet Needs of Surgical Care for Children: A Case Study in the Brazilian Publicly-Financed Health System.

Objective To measure and document the clinical impact of the waiting time for surgical treatment of patients with spinal deformities in a quaternary center in Brazil. Methods In total, 59 patients with spinal deformity waiting for surgery on our hospital's list were evaluated to observe the impact of the waiting time on the progression of the deformity. Patient evaluation was performed using the SRS-22r questionnaire for health-related quality of life (HRQL) and radiographic images to evaluate the deformity of the spine at the time the patients were included in the waiting list and at the most recent appointment. The radiographic parameters selected for comparison were: Cobb angle of the primary and secondary curves, coronal alignment, apical vertebral translation, pelvic obliquity, sagittal vertebral axis, kyphosis (T5-T12), and lordosis (L1-S1). Results Low HRQL scores according to the SRS-22r questionnaire were observed in patients waiting for surgery. The radiographic parameters showed progression of the deformity on the initial evaluation when compared with the most recent follow-up evaluation. Conclusion The patients waiting for surgical treatment of spinal deformities in our center showed relatively low HRQL scores and radiographic progression of the deformity.

Unmet Needs of Surgical Care for Children: A Case Study in the Brazilian Publicly-Financed Health System / Necessidades não atendidas de cuidados cirúrgicos para crianças: Estudo de caso no Sistema Único de Saúde financiado pelo governo no Brasil

Abstract Objective To measure and document the clinical impact of the waiting time for surgical treatment of patients with spinal deformities in a quaternary center in Brazil. Methods In total, 59 patients with spinal deformity waiting for surgery on our hospital's list were evaluated to observe the impact of the waiting time on the progression of the deformity. Patient evaluation was performed using the SRS-22r questionnaire for health-related quality of life (HRQL) and radiographic images to evaluate the deformity of the spine at the time the patients were included in the waiting list and at the most recent appointment. The radiographic parameters selected for comparison were: Cobb angle of the primary and secondary curves, coronal alignment, apical vertebral translation, pelvic obliquity, sagittal vertebral axis, kyphosis (T5-T12), and lordosis (L1-S1). Results Low HRQL scores according to the SRS-22r questionnaire were observed in patients waiting for surgery. The radiographic parameters showed progression of the deformity on the initial evaluation when compared with the most recent follow-up evaluation. Conclusion The patients waiting for surgical treatment of spinal deformities in our center showed relatively low HRQL scores and radiographic progression of the deformity.

Resumo Objetivo Medir e documentar o impacto clínico do tempo de espera para tratamento cirúrgico de pacientes com deformidades na coluna vertebral em um centro quaternário no Brasil. Métodos No total, 59 pacientes com deformidade espinhal à espera de cirurgia na lista do nosso hospital foram avaliados para observar o impacto dos tempos de espera na progressão da deformidade. A avaliação do paciente foi realizada utilizando o questionário SRS-22r para qualidade de vida relacionada à saúde (QLRS), e imagens radiográficas para avaliar a deformidade da coluna vertebral quando os pacientes foram incluídos na lista de espera e na consulta mais recente. Os parâmetros radiográficos selecionados para comparação foram: ângulo de Cobb de curvas primárias e secundárias, alinhamento coronal, translação de vértebra apical, obliquidade pélvica, eixo vertebral sagital, cifose (T5-T12), e lordose (L1-S1). Resultados Baixos escores de QLRS segundo o questionário SRS-22r foram observados em pacientes que aguardavam cirurgia. Os parâmetros radiográficos mostraram progressão da deformidade na avaliação inicial em comparação com a avaliação de seguimento mais recente. Conclusão Os pacientes que aguardavam tratamento cirúrgico de deformidade espinhal em nosso centro apresentaram os escores de QLRS relativamente baixos e progressão radiográfica da deformidade.

Early Complications in Vertical Expandable Prosthetic Titanium Rib and Magnetically Controlled Growing Rods to Manage Early Onset Scoliosis.

OBJECTIVES: The aim of this study is to examine whether surgical treatment of early onset scoliosis (EOS) with magnetically controlled growing rods (MCGRs) or a vertical expandable prosthetic titanium rib (VEPTR) resulted in fewer short-term (24 months) complications and reoperations. BACKGROUND: EOS is a challenging problem for spine surgeons that has been managed with different growth-friendly instrumentation systems. Although rib-based devices encourage spinal growth via regular lengthening, the high rate of complications and reoperations leads us to use spine-based devices such as MCGRs to mitigate this concern. METHODS: A total of 35 EOS patients were included in the study. Twenty patients were included in the VEPTR group, and 15 patients were included in the MCGR group. Demographic data and 2 years of postoperative complications and reoperations were reviewed retrospectively. As secondary outcomes, radiographic outcomes were reported preoperatively and 1 year after surgery. Indications for this technique and complications were collected from the charts. RESULTS: Demographic data showed no significant differences between the 2 groups. Significant differences were found in the complications rate at 2 years, with 65% complications in the VEPTR group and 13.3% complications in the MCGR group (P < .001). The reoperation rate at 2 years was also significantly higher in the VEPTR group, with 50% versus 13.3% in the MCGR group (P = .0009). As secondary outcomes, radiological parameters such as main curve Cobb angle correction (P = .001) and apical vertebral translation (P = .002) were significantly higher in the MCGR group. Significant differences were also found in sagittal profile parameters; T1-T12 and T1-S1 were significantly higher in the MCGR group (P < .001). CONCLUSIONS: According to our results, VEPTR has significantly higher complication and reoperation rates at 2 years postsurgery compared with MCGR. LEVEL OF EVIDENCE: 4.

Plastid phylogenomics resolves ambiguous relationships within the orchid family and provides a solid timeframe for biogeography and macroevolution.

Recent phylogenomic analyses based on the maternally inherited plastid organelle have enlightened evolutionary relationships between the subfamilies of Orchidaceae and most of the tribes. However, uncertainty remains within several subtribes and genera for which phylogenetic relationships have not ever been tested in a phylogenomic context. To address these knowledge-gaps, we here provide the most extensively sampled analysis of the orchid family to date, based on 78 plastid coding genes representing 264 species, 117 genera, 18 tribes and 28 subtribes. Divergence times are also provided as inferred from strict and relaxed molecular clocks and birth-death tree models. Our taxon sampling includes 51 newly sequenced plastid genomes produced by a genome skimming approach. We focus our sampling efforts on previously unplaced clades within tribes Cymbidieae and Epidendreae. Our results confirmed phylogenetic relationships in Orchidaceae as recovered in previous studies, most of which were recovered with maximum support (209 of the 262 tree branches). We provide for the first time a clear phylogenetic placement for Codonorchideae within subfamily Orchidoideae, and Podochilieae and Collabieae within subfamily Epidendroideae. We also identify relationships that have been persistently problematic across multiple studies, regardless of the different details of sampling and genomic datasets used for phylogenetic reconstructions. Our study provides an expanded, robust temporal phylogenomic framework of the Orchidaceae that paves the way for biogeographical and macroevolutionary studies.

Floral glands in myophilous and sapromyophilous species of Pleurothallidinae (Epidendroideae, Orchidaceae)-osmophores, nectaries, and a unique sticky gland.

Pleurothallidinae orchids have been the focus of many multidisciplinary studies due to their challenging systematics and taxonomy. The synapomorphies already recognized in the group are mostly related to floral characters, the last proposed being the occurrence of alkanes in the floral fragrance. The composition of the floral bouquet varied significantly among the studied species, leading us to hypothesize that the variations in volatiles emitted could be linked to the structure of osmophores, especially when comparing the myophilous and sapromyophilous pollination syndromes. Sepals and labellum at different developmental stages of seven Brazilian Pleurothallidinae species were examined using light, scanning, and transmission electron microscopy. Nectar reabsorption was assessed by Lucifer Yellow CH tracer and imaged under confocal microscopy. Nectaries were restricted to the labellum of the myophilous species, whereas osmophores occurred in the dorsal and/or lateral sepals, varying according to species. In the sapromyophilous species, floral nectaries were not detected and osmophores were restricted to the labellum. Osmophore structure was correlated with the volatiles emitted, being the trichome osmophores notably present on the sepals of both myophilous species that possess nectaries. For the first time, we demonstrated reabsorption of the released nectar in Pleurothallidinae and the occurrence of a unique gland named sticky-exudate glands, which occurred in the lateral sepals and labellum of Echinosepala aspasicensis, a sapromyophilous species, that released a heterogeneous exudate composed of polysaccharides and lipids. Similar glands have been reported in Bulbophyllum, highlighting the convergence between both groups.

Peculiar relationships among morphology, burrowing performance and sand type in two fossorial microteiid lizards.

Associations among ecology, morphology and locomotor performance have been intensively investigated in several vertebrate lineages. Knowledge on how phenotypes evolve in natural environments likely benefits from identification of circumstances that might expand current ecomorphological equations. In this study, we used two species of Calyptommatus lizards from Brazilian Caatingas to evaluate if specific soil properties favor burrowing performance. As a derived prediction, we expected that functional associations would be easily detectable at the sand condition that favors low-resistance burrowing. We collected two endemic lizards and soil samples in their respective localities, obtained morphological data and recorded performance of both species in different sand types. As a result, the two species burrowed faster at the fine and homogeneous sand, the only condition where we detected functional associations between morphology and locomotion. In this sand type, lizards from both Calyptommatus species that have higher trunks and more concave heads were the ones that burrowed faster, and these phenotypic traits did not morphologically discriminate the two Calyptommatus populations studied. We discuss that integrative approaches comprising manipulation of environmental conditions clearly contribute to elucidate processes underlying phenotypic evolution in fossorial lineages.

Inflammasomes are activated in response to SARS-CoV-2 infection and are associated with COVID-19 severity in patients.

Severe cases of COVID-19 are characterized by a strong inflammatory process that may ultimately lead to organ failure and patient death. The NLRP3 inflammasome is a molecular platform that promotes inflammation via cleavage and activation of key inflammatory molecules including active caspase-1 (Casp1p20), IL-1ß, and IL-18. Although participation of the inflammasome in COVID-19 has been highly speculated, the inflammasome activation and participation in the outcome of the disease are unknown. Here we demonstrate that the NLRP3 inflammasome is activated in response to SARS-CoV-2 infection and is active in COVID-19 patients. Studying moderate and severe COVID-19 patients, we found active NLRP3 inflammasome in PBMCs and tissues of postmortem patients upon autopsy. Inflammasome-derived products such as Casp1p20 and IL-18 in the sera correlated with the markers of COVID-19 severity, including IL-6 and LDH. Moreover, higher levels of IL-18 and Casp1p20 are associated with disease severity and poor clinical outcome. Our results suggest that inflammasomes participate in the pathophysiology of the disease, indicating that these platforms might be a marker of disease severity and a potential therapeutic target for COVID-19.

Staged instrumentation with magnetically controlled growing rods in early-onset scoliosis: indications and preliminary outcomes.

BACKGROUND: Severe scoliosis, kyphosis, stiffer curves, short trunk height, and poor bone density are known risk factors for instrumentation failure with traditional growing rods or magnetically controlled growing rods (MCGR). To minimize the risk of instrumentation failure in managing complex early-onset scoliosis (EOS) with MCGR, we propose a strategy for staged MCGR insertion. METHODS: We performed a single-center retrospective review of all consecutive MCGR cases with 24 months' minimum follow-up. Inclusion criteria included diagnosis of EOS of any etiology with severe and stiff curves in the coronal or sagittal planes, poor bone density, short trunk height (T1-T12 smaller than 150 mm) or previous instrumentation failure managed with staged MCGR. During the first stage, anchor points and halo-gravity were applied, followed by halo-gravity traction. At a second stage, halo-gravity was removed and MCGR were inserted. Outcome measures included pre- and postoperative radiographic measurements and complications. RESULTS: Seventeen patients with a median age of 7 (range 6-9) years were managed in two stages. Indications for two-stage surgery were short trunk height (T1-T12 height less than 150 mm) in six patients, five poor bone quality, three dislodgement of proximal anchor points in previous instrumentation, and three rigid curves. The rate of unplanned revision surgeries was 11.8%. No infections or traction-related complications were found. CONCLUSIONS: According to our results, the staged MCGR insertion strategy combined with halo-gravity traction to manage complex EOS yielded a relatively low instrumentation failure rate as compared with the rates previously reported in the current literature. To our knowledge, this is the first study reporting the staged strategy for instrumentation with MCGR. LEVEL OF EVIDENCE: IV.

Thermal and salinity effects on locomotor performance of Thoropa taophora tadpoles (Anura, Cycloramphidae).

It is well known that environmental temperature influences several biological functions of ectotherms, notably in amphibians. The high permeability of anuran skin, associated with the effect of elevated environmental temperature, potentiates the dehydration process and this combination may restrict locomotor performance. Thoropa taophora is an endemic species from the Atlantic Rainforest whose tadpoles are semiterrestrial and predominantly diurnal, and are found in rocky seashores where they are exposed to sea spray and high temperatures. In this study we investigated how temperature and salinity conditions affect the locomotor performance in Thoropa taophora tadpoles. We also assessed how different osmotic concentrations affect the activity of the metabolic pathways that support muscle function. We measured the sprint speed of tadpoles of various sizes at different temperatures and salinities in the field. We also measured the activity of the enzymes pyruvate kinase (PK), lactate dehydrogenase (LDH) and citrate synthase (CS) in different temperatures and osmotic concentrations, and calculated the thermal sensitivity and the activity constants for each osmolality. Our results showed that, in general, sprint speed decreased with increasing temperature and salinity. However, whereas the effect of increased salinity was similar in smaller and larger tadpoles, increased temperature had a higher negative impact on sprint speed of larger tadpoles, thus indicating low thermal sensitivity of small tadpoles. PK and LDH thermal sensitivities and LDH constant of activity decreased as the osmolality increased. In conclusion, the locomotor capacity of tadpoles was decreased by temperature and salinity, which may be related to a decrease in anaerobic metabolism both in terms of sensitivity and total energy turnover through enzymatic activity. We discuss the ecological consequences, including the potential impacts on predator escape behavior promoted by changes in metabolism and locomotor performance in an early stage of development of this species.

Pedicle Screw Instrumentation in Scoliosis Surgery: On Site Simulation Data on Accuracy and Efficiency With Different Techniques.

STUDY DESIGN: Prospective experimental study with on-site simulation. OBJECTIVE: To compare the accuracy and efficiency of different techniques for pedicle screw instrumentation (PSI). SUMMARY OF BACKGROUND DATA: Improving the safety and efficiency of PSI is a critical step to reduce the complication rates and the cost of scoliosis surgery. Innovative operative techniques for PSI have shown to safely improve efficiency, thereby reducing cost. Surgical simulation is a valuable tool to study different operative techniques. METHODS: Five spine fellows instrumented 20 simulation models of a scoliotic spine with 10 pedicle screws per model. Four techniques were studied, including the conventional pedicle probe and the innovative sequential drilling technique, with or without computed tomography (CT)-based navigation. Our primary outcome measures were efficiency and accuracy of PSI. We analyzed the data with bivariate analyses using the Chi-square test for categorical variables and the Student t test or ANalysis Of VAriance with Bonferroni post-hoc tests for continuous variables. RESULTS: The drilling techniques (free hand and navigated) were more efficient as compared with the pedicle probe techniques (P < 0.01). The navigated techniques resulted in better accuracy as compared with the free hand techniques (P = 0.036). Most pedicle breaches were medial (n = 32/52). The concave apical pedicle (T4 right side) had the highest incidence of breaches. There was no significant difference in efficiency comparing the free hand and the navigated pedicle probe techniques (P = 0.261) or comparing the free hand drilling and the navigated drilling techniques (P = 1.00). CONCLUSION: On site surgical simulation is a promising concept for teaching advanced procedural skills. Our findings suggest that navigation improves the accuracy of PSI while sequential drilling safely improves efficiency. Combining navigation with sequential drilling can significantly improve the accuracy and the efficiency of PSI in scoliosis surgery, as previously suggested with our published clinical data. LEVEL OF EVIDENCE: 4.

Quality, Safety, and Value of Innovating Classic Operative Techniques in Scoliosis Surgery: Intraoperative Traction and Navigated Sequential Drilling.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aims to measure and describe the clinical and financial implications of the systematic implementation of intraoperative skull-femoral traction (IOSFT) and navigated sequential drilling (NSD) for posterior spinal instrumentation and fusion (PSIF) in adolescent idiopathic scoliosis (AIS) at our institution. SUMMARY OF BACKGROUND DATA: PSIF has been the standard surgical treatment for AIS. This retrospective single-center quality improvement study describes the perioperative outcomes and impact on health resource utilization following the systematic application of two classic surgical strategies modified using current technology: IOSFT and NSD. METHODS: We reviewed the medical records of 125 patients who underwent a single-stage PSIF for AIS. We identified three cohorts based on surgical strategies used intraoperatively. Traditional techniques (n = 28), IOSFT (n = 45), and IOSFT plus NSD (n = 52). The primary outcome measures were operative time, prevalence of cases requiring extended operating room time, need for blood transfusion, length of hospital stay, and cost per surgery. Secondary outcomes included implant density, degree of spine deformity correction, and perioperative complications. RESULTS: All primary outcome measures improved significantly (p < .001). Median operating time decreased by 59%. Use of late operating room hours fell from 89% to 0% and transfusion rates from 64% to 1.9%. Length of hospital stay decreased from 6 to 4 days. Comprehensive cost per case decreased by 24%. DISCUSSION: Together, IOSFT and NSD improved the quality, safety, and value of care. These surgical strategies were performed without increased perioperative complications, while reducing cost per case by 24%. CONCLUSIONS: The data presented may have significant implications in health resource utilization for AIS surgery. LEVEL OF EVIDENCE: Level III.

Sagittal Balance in Adolescent Idiopathic Scoliosis Managed With Intraoperative Skull Femoral Traction.

STUDY DESIGN: This is a retrospective cohort, single-center quality improvement study. OBJECTIVES: To evaluate the effect of the intraoperative skull femoral traction (IOSFT) on sagittal balance in posterior spinal instrumentation (PSI) to manage scoliosis. SUMMARY OF BACKGROUND DATA: IOSFT has been used routinely as an adjunct technique for facilitating PSI to manage scoliosis in our institution since 2010. Previous studies have raised concerns regarding the negative effect of IOSFT on lumbar lordosis. MATERIALS AND METHODS: The medical records and radiographs of 113 patients with adolescent idiopathic scoliosis managed with single stage PSI were reviewed. Eighty-five patients were operated with IOSFT (traction group) and 28 patients were operated without traction (nontraction group). Patients who had double (anterior-posterior) approaches or nonidiopathic scoliosis were excluded. Sagittal balance and pelvic parameters at 2 years of postoperative follow-up were the primary outcome measures. Statistical analysis was done with R for statistical computing. Median values and interquartile range were compared between groups using Wilcoxon rank sum, Fischer exact, and Welch t tests. P-values of <0.05 were considered statistically significant. RESULTS: No significant differences were found comparing postoperative lumbar lordosis in the nontraction group (54 degrees) with the traction group (53 degrees) (P=0.4953). No significant differences were found in postoperative sagittal vertical axis medians comparing both groups, with 17 mm in the nontraction group and 18 mm in the traction group (P=0.3994). No significant differences were found in postoperative pelvic parameters. The median pelvic incidence was 52 degrees in the nontraction group and 50 degrees in the traction group (P=0.2711). CONCLUSIONS: According to our results, the use of IOSFT as an adjunct to facilitate PSI for managing adolescent idiopathic scoliosis had no measurable negative impact on sagittal balance in our IOSFT cohort.