Fast and sensitive GCaMP calcium indicators for imaging neural populations.

Calcium imaging with protein-based indicators1,2 is widely used to follow neural activity in intact nervous systems, but current protein sensors report neural activity at timescales much slower than electrical signalling and are limited by trade-offs between sensitivity and kinetics. Here we used large-scale screening and structure-guided mutagenesis to develop and optimize several fast and sensitive GCaMP-type indicators3-8. The resulting 'jGCaMP8' sensors, based on the calcium-binding protein calmodulin and a fragment of endothelial nitric oxide synthase, have ultra-fast kinetics (half-rise times of 2 ms) and the highest sensitivity for neural activity reported for a protein-based calcium sensor. jGCaMP8 sensors will allow tracking of large populations of neurons on timescales relevant to neural computation.

Reactive Chlorine Emissions from Cleaning and Reactive Nitrogen Chemistry in an Indoor Athletic Facility.

Indoor gas-phase radical sources are poorly understood but expected to be much different from outdoors. Several potential radical sources were measured in a windowless, light-emitting diode (LED)-lit room in a college athletic facility over a 2 week period. Alternating measurements between the room air and the supply air of the heating, ventilation, and air-conditioning system allowed an assessment of sources. Use of a chlorine-based cleaner was a source of several photolabile reactive chlorine compounds, including ClNO2 and Cl2. During cleaning events, photolysis rates for these two compounds were up to 0.0023 pptv min-1, acting as a source of chlorine atoms even in this low-light indoor environment. Unrelated to cleaning events, elevated ClNO2 was often observed during daytime and lost to ventilation. The nitrate radical (NO3), which is rapidly photolyzed outdoors during daytime, may persist in low-light indoor environments. With negligible photolysis, loss rates of NO3 indoors were dominated by bimolecular reactions. At times with high NO2 and O3 ventilated from outdoors, N2O5 was observed. Elevated ClNO2 measured concurrently suggests the formation through heterogeneous reactions, acting as an additional source of reactive chlorine within the athletic facility and outdoors.

Phylogenetic analyses and reclassification of the oleaginous marine species Nannochloris sp. "desiccata" (Trebouxiophyceae, Chlorophyta), formerly Chlorella desiccata, supported by a high-quality genome assembly.

Microalgae are diverse, with many gaps remaining in phylogenetic and physiological understanding. Thus, studying new microalgae species increases our broader comprehension of biological diversity, and evaluation of new candidates as algal production platforms can lead to improved productivity under a variety of cultivation conditions. Chlorella is a genus of fast-growing species often isolated from freshwater habitats and cultivated as a source of nutritional supplements. However, the use of freshwater increases competition with other freshwater needs. We identified Chlorella desiccata to be worthy of further investigation as a potential algae production strain, due to its isolation from a marine environment and its promising growth and biochemical composition properties. Long-read genomic sequencing was conducted for C. desiccata UTEX 2526, resulting in a high-quality, near chromosome level, diploid genome with an assembly length of 21.55 Mbp in only 18 contigs. We also report complete circular mitochondrial and chloroplast genomes. Phylogenomic and phylogenetic analyses using nuclear, chloroplast, 18S rRNA, and actin sequences revealed that this species clades within strains currently identified as Nannochloris (Trebouxiophyceae, Chlorophyta), leading to its reclassification as Nannochloris sp. "desiccata" UTEX 2526. The mode of cell division for this species is autosporulation, differing from the type species N. bacillaris. As has occurred across multiple microalgae genera, there are repeated examples of Nannochloris species reclassification in the literature. This high-quality genome assembly and phylogenetic analysis of the potential algal production strain Nannochloris sp. "desiccata" UTEX 2526 provides an important reference and useful tool for further studying this region of the phylogenetic tree.

Real-time organic aerosol chemical speciation in the indoor environment using extractive electrospray ionization mass spectrometry.

Understanding the sources and composition of organic aerosol (OA) in indoor environments requires rapid measurements, since many emissions and processes have short timescales. However, real-time molecular-level OA measurements have not been reported indoors. Here, we present quantitative measurements, at a time resolution of five seconds, of molecular ions corresponding to diverse aerosol-phase species, by applying extractive electrospray ionization mass spectrometry (EESI-MS) to indoor air analysis for the first time, as part of the highly instrumented HOMEChem field study. We demonstrate how the complex spectra of EESI-MS are screened in order to extract chemical information and investigate the possibility of interference from gas-phase semivolatile species. During experiments that simulated the Thanksgiving US holiday meal preparation, EESI-MS quantified multiple species, including fatty acids, carbohydrates, siloxanes, and phthalates. Intercomparisons with Aerosol Mass Spectrometer (AMS) and Scanning Mobility Particle Sizer suggest that EESI-MS quantified a large fraction of OA. Comparisons with FIGAERO-CIMS shows similar signal levels and good correlation, with a range of 100 for the relative sensitivities. Comparisons with SV-TAG for phthalates and with SV-TAG and AMS for total siloxanes also show strong correlation. EESI-MS observations can be used with gas-phase measurements to identify co-emitted gas- and aerosol-phase species, and this is demonstrated using complementary gas-phase PTR-MS observations.

Quantification and source characterization of volatile organic compounds from exercising and application of chlorine-based cleaning products in a university athletic center.

Humans spend approximately 90% of their time indoors, impacting their own air quality through occupancy and activities. Human VOC emissions indoors from exercise are still relatively uncertain, and questions remain about emissions from chlorine-based cleaners. To investigate these and other issues, the ATHLETic center study of Indoor Chemistry (ATHLETIC) campaign was conducted in the weight room of the Dal Ward Athletic Center at the University of Colorado Boulder. Using a Vocus Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (Vocus PTR-TOF), an Aerodyne Gas Chromatograph (GC), an Iodide-Chemical Ionization Time-of-Flight Mass Spectrometer (I-CIMS), and Picarro cavity ringdown spectrometers, we alternated measurements between the weight room and supply air, allowing for determination of VOC, NH3 , H2 O, and CO2 emission rates per person (emission factors). Human-derived emission factors were higher than previous studies of measuring indoor air quality in rooms with individuals at rest and correlated with increased CO2 emission factors. Emission factors from personal care products (PCPs) were consistent with previous studies and typically decreased throughout the day. In addition, N-chloraldimines were observed in the gas phase after the exercise equipment was cleaned with a dichlor solution. The chloraldimines likely originated from reactions of free amino acids with HOCl on gym surfaces.

Molecular expression patterns in the synovium and their association with advanced symptomatic knee osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a major source of knee pain. Mechanisms of OA knee pain are incompletely understood but include synovial pathology. We aimed to identify molecular expression patterns in the synovium associated with symptomatic knee OA. DESIGN: Snap frozen synovia were from people undergoing total knee replacement (TKR) for advanced OA, or from post-mortem (PM) cases who had not sought help for knee pain. Associations with OA symptoms were determined using discovery and validation samples, each comprising TKR and post mortem (PM) cases matched for chondropathy (Symptomatic or Asymptomatic Chondropathy). Associations with OA were determined by comparing age matched TKR and PM control cases. Real-time quantitative PCR for 96 genes involved in inflammation and nerve sensitisation used TaqMan® Array Cards in discovery and validation samples, and protein expression for replicated genes was quantified using Luminex bead assay. RESULTS: Eight genes were differentially expressed between asymptomatic and symptomatic chondropathy cases and replicated between discovery and validation samples (P<0.05 or >3-fold change). Of these, matrix metalloprotease (MMP)-1 was also increased whereas interleukin-1 receptor 1 (IL1R1) and vascular endothelial growth factor (VEGF) were decreased at the protein level in the synovium of symptomatic compared to asymptomatic chondropathy cases. MMP1 protein expression was also increased in OA compared to PM controls. CONCLUSION: Associations of symptomatic OA may suggest roles of MMP1 expression and IL1R1 and VEGF pathways in OA pain. Better understanding of which inflammation-associated molecules mediate OA pain should inform refinement of existing therapies and development of new treatments.

Pain prediction by serum biomarkers of bone turnover in people with knee osteoarthritis: an observational study of TRAcP5b and cathepsin K in OA.

OBJECTIVES: To investigate serum biomarkers, tartrate resistant acid phosphatase 5b (TRAcP5b) and cathepsin K (cath-K), indicative of osteoclastic bone resorption, and their relationship to pain and pain change in knee osteoarthritis (OA). METHODS: Sera and clinical data were collected from 129 people (97 with 3-year follow-up) with knee OA from the Prediction of Osteoarthritis Progression (POP) cohort. Knee OA-related outcomes in POP included: WOMAC pain, National Health and Nutrition Examination Survey (NHANES) I (pain, aching and stiffness), subchondral sclerosis, and radiographically determined tibiofemoral and patellofemoral OA. Two putative osteoclast biomarkers were measured in sera: TRAcP5b and cath-K. Medial tibia plateaux were donated at knee arthroplasty for symptomatic OA (n = 84) or from 16 post mortem (PM) controls from the Arthritis Research UK (ARUK) Pain Centre joint tissue repository. Osteoclasts were stained for tartrate resistant acid phosphatase (TRAcP) within the subchondral bone of the medial tibia plateaux. RESULTS: Serum TRAcP5b activity, but not cath-K-immunoreactivity, was associated with density of TRAcP-positive osteoclasts in the subchondral bone of medial tibia plateaux. TRAcP-positive osteoclasts were more abundant in people with symptomatic OA compared to controls. Serum TRAcP5b activity was associated with baseline pain and pain change. CONCLUSIONS: Our observations support a role for subchondral osteoclast activity in the generation of OA pain. Serum TRAcP5b might be a clinically relevant biomarker of disease activity in OA.

Histopathological subgroups in knee osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a heterogeneous, multi-tissue disease. We hypothesised that different histopathological features characterise different stages during knee OA progression, and that discrete subgroups can be defined based on validated measures of OA histopathological features. DESIGN: Medial tibial plateaux and synovium were from 343 post-mortem (PM) and 143 OA arthroplasty donations. A 'chondropathy/osteophyte' group (n = 217) was classified as PM cases with osteophytes or macroscopic medial tibiofemoral chondropathy lesions ≥grade 3 to represent pre-surgical (early) OA. 'Non-arthritic' controls (n = 48) were identified from the remaining PM cases. Mankin histopathological scores were subjected to Rasch analysis and supplemented with histopathological scores for subchondral bone marrow replacement and synovitis. Item weightings were derived by principle components analysis (PCA). Histopathological subgroups were sought using latent class analysis (LCA). RESULTS: Chondropathy, synovitis and osteochondral pathology were each associated with OA at arthroplasty, but each was also identified in some 'non-arthritic' controls. Tidemark breaching in the chondropathy/osteophyte group was greater than in non-arthritic controls. Three histopathological subgroups were identified, characterised as 'mild OA', or 'severe OA' with mild or moderate/severe synovitis. CONCLUSIONS: Presence and severity of synovitis helps define distinct histopathological OA subgroups. The absence of a discrete 'normal' subgroup indicates a pathological continuum between normality and OA status. Identifying specific pathological processes and their clinical correlates in OA subgroups has potential to accelerate the development of more effective therapies.

Determination of diffusion profiles in altered wellbore cement using X-ray computed tomography methods.

The development of accurate, predictive models for use in determining wellbore integrity requires detailed information about the chemical and mechanical changes occurring in hardened Portland cements. X-ray computed tomography (XRCT) provides a method that can nondestructively probe these changes in three dimensions. Here, we describe a method for extracting subvoxel mineralogical and chemical information from synchrotron XRCT images by combining advanced image segmentation with geochemical models of cement alteration. The method relies on determining "effective linear activity coefficients" (ELAC) for the white light source to generate calibration curves that relate the image grayscales to material composition. The resulting data set supports the modeling of cement alteration by CO2-rich brine with discrete increases in calcium concentration at reaction boundaries. The results of these XRCT analyses can be used to further improve coupled geochemical and mechanical models of cement alteration in the wellbore environment.

Chemical and mechanical properties of wellbore cement altered by CO2-rich brine using a multianalytical approach.

Defining chemical and mechanical alteration of wellbore cement by CO(2)-rich brines is important for predicting the long-term integrity of wellbores in geologic CO(2) environments. We reacted CO(2)-rich brines along a cement-caprock boundary at 60 °C and pCO(2) = 3 MPa using flow-through experiments. The results show that distinct reaction zones form in response to reactions with the brine over the 8-day experiment. Detailed characterization of the crystalline and amorphous phases, and the solution chemistry show that the zones can be modeled as preferential portlandite dissolution in the depleted layer, concurrent calcium silicate hydrate (CSH) alteration to an amorphous zeolite and Ca-carbonate precipitation in the carbonate layer, and carbonate dissolution in the amorphous layer. Chemical reaction altered the mechanical properties of the core lowering the average Young's moduli in the depleted, carbonate, and amorphous layers to approximately 75, 64, and 34% of the unaltered cement, respectively. The decreased elastic modulus of the altered cement reflects an increase in pore space through mineral dissolution and different moduli of the reaction products.

The State of Machine Learning in Spine Surgery: A Systematic Review.

STUDY DESIGN: This was a systematic review of existing literature. OBJECTIVE: The objective of this study was to evaluate the current state-of-the-art trends and utilization of machine learning in the field of spine surgery. SUMMARY OF BACKGROUND DATA: The past decade has seen a rise in the clinical use of machine learning in many fields including diagnostic radiology and oncology. While studies have been performed that specifically pertain to spinal surgery, there have been relatively few aggregate reviews of the existing scientific literature as applied to clinical spine surgery. METHODS: This study utilized Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to review the scientific literature from 2009 to 2019 with syntax specific for machine learning and spine surgery applications. Specific data was extracted from the available literature including algorithm application, algorithms tested, database type and size, algorithm training method, and outcome of interest. RESULTS: A total of 44 studies met inclusion criteria, of which the majority were level III evidence. Studies were grouped into 4 general types: diagnostic tools, clinical outcome prediction, surgical assessment tools, and decision support tools. Across studies, a wide swath of algorithms were used, which were trained across multiple disparate databases. There were no studies identified that assessed the ethical implementation or patient perceptions of machine learning in clinical care. CONCLUSIONS: The results reveal the broad range of clinical applications and methods used to create machine learning algorithms for use in the field of spine surgery. Notable disparities exist in algorithm choice, database characteristics, and training methods. Ongoing research is needed to make machine learning operational on a large scale.

The lexicon of multirod constructs in adult spinal deformity: a concise description of when, why, and how.

The use of multirod constructs in the setting of adult spinal deformity (ASD) began to prevent rod fracture and pseudarthrosis near the site of pedicle subtraction osteotomies (PSOs) and 3-column osteotomies (3COs). However, there has been unclear and inconsistent nomenclature, both clinically and in the literature, for the various techniques of supplemental rod implantation. In this review the authors aim to provide the first succinct lexicon of multirod constructs available for the treatment of ASD, providing a universal nomenclature and definition for each type of supplementary rod. The primary rod of ASD constructs is the longest rod that typically spans from the bottom of the construct to the upper instrumented vertebrae. The secondary rod is shorter than the primary rod, but is connected directly to pedicle screws, albeit fewer of them, and connects to the primary rod via lateral connectors or cross-linkers. Satellite rods are a 4-rod technique in which 2 rods span only the site of a 3CO via pedicle screws at the levels above and below, and are not connected to the primary rod (hence the term "satellite"). Accessory rods are connected to the primary rods via side connectors and buttress the primary rod in areas of high rod strain, such as at a 3CO or the lumbosacral junction. Delta rods span the site of a 3CO, typically a PSO, and are not contoured to the newly restored lordosis of the spine, thus buttressing the primary rod above and below a 3CO. The kickstand rod itself functions as an additional means of restoring coronal balance and is secured to a newly placed iliac screw on the side of truncal shift and connected to the primary rod; distracting against the kickstand then helps to correct the concavity of a coronal curve. The use of multirod constructs has dramatically increased over the last several years in parallel with the increasing prevalence of ASD correction surgery. However, ambiguity persists both clinically and in the literature regarding the nomenclature of each supplemental rod. This nomenclature of supplemental rods should help unify the lexicon of multirod constructs and generalize their usage in a variety of scientific and clinical scenarios.

Complications in the Elderly Population Undergoing Spinal Deformity Surgery: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic Review and Meta-Analysis. OBJECTIVES: The elderly have an increased risk of perioperative complications for Adult Spinal Deformity (ASD) corrections. Stratification of these perioperative complications based on risk type and specific risk factors, however, remain unclear. This paper will systematically review perioperative risk factors in the elderly undergoing ASD correction stratified by type: medical, implant-related, proximal junctional kyphosis (PJK), and need for revision surgery. METHODS: A systematic review was performed using the PRISMA guidelines. A query of PubMed was performed to identify publications pertinent to ASD in the elderly. Publications included in this review focused on patients ≥65 years old who underwent operative management for ASD to assess for risk factors of perioperative complications. RESULTS: A total of 734 unique citations were screened resulting in ten included articles for this review. Pooled incidence of perioperative complications included medical complications (21%), implant-related complications (16%), PJK (29%), and revision surgery (13%). Meta-analysis calculated greater preoperative PT (WMD 2.66; 95% Cl .36-4.96; P = .02), greater preoperative SVA (WMD 2.24; 95% Cl .62-3.86; P = .01), and greater postoperative SVA (WMD .97; 95% Cl .03-1.90; P = .04) to significantly correlate with development of PJK with no evidence of publication bias or concerns in study heterogeneity. CONCLUSIONS: There is a paucity of literature describing perioperative complications in the elderly following ASD surgery. Appropriate understanding of modifiable risk factors for the development of medical and implant-related complications, proximal junctional kyphosis, and revision surgeries presents an opportunity to decrease morbidity and improve patient outcomes.

The Number of Organ System Injuries Is a Predictor of Intrahospital Mortality in Complete Cervical Spinal Cord Injury.

OBJECTIVE: We sought to determine the extent to which polytrauma significantly impacts intrahospital mortality among patients with complete cervical spinal cord injury (cSCI) and to assess whether an organ system-based approach would be appropriate as a mortality predictor as compared with conventional standards to help guide prognosis and management. METHODS: We retrospectively reviewed patient medical records and assessed the type of associated trauma at presentation. We then reviewed its correlation with mortality in patients who were admitted at our institution between 2012 and 2021. Types of associated trauma were classified under the following: traumatic brain injury, abdominal injury, thoracic injury, orthopedic injury, craniofacial injury, genitourinary injury, and vascular injury. RESULTS: Thirty patients with complete cSCIs were identified. Increased organ system-based polytrauma had a statistically significant increase in intrahospital mortality (P = 0.01). Using the logistic regression model, for each additional gain in organ system-based trauma, patients had a 2.455 odds ratio of mortality (P = 0.03, 95% confidence interval 1.171-6.348). Zero other organ system injuries in the setting of cSCI provided a predictive mortality probability of 6.6%. One organ system-based trauma provided a 14.8% intrahospital mortality probability, 2 traumas provided a 29.9% mortality probability, 3 traumas provided a 51.1% mortality probability, and 4 other organ-system traumas provided a 72.0% mortality probability. The predictive prognostic accuracy of using number of organ system-based trauma to predict mortality probability was quantified at area under the curve = 0.8264 (95% confidence interval 0.6729-0.9799, P = 0.01). CONCLUSIONS: Our research shows that an increased number of organ system injuries is associated with greater intrahospital mortality in polytrauma patients with complete cSCI.

Speciation of pelagic zooplankton: Invisible boundaries can drive isolation of oceanic ctenophores.

The study of evolution and speciation in non-model systems provides us with an opportunity to expand our understanding of biodiversity in nature. Connectivity studies generally focus on species with obvious boundaries to gene flow, but in open-ocean environments, such boundaries are difficult to identify. Due to the lack of obvious boundaries, speciation and population subdivision in the pelagic environment remain largely unexplained. Comb jellies (Phylum Ctenophora) are mostly planktonic gelatinous invertebrates, many of which are considered to have freely interbreeding distributions worldwide. It is thought that the lobate ctenophore Bolinopsis infundibulum is distributed throughout cooler northern latitudes and B. vitrea warmer. Here, we examined the global population structure for species of Bolinopsis with genetic and morphological data. We found distinct evolutionary patterns within the genus, where B. infundibulum had a broad distribution from northern Pacific to Atlantic waters despite many physical barriers, while other species were geographically segregated despite few barriers. Divergent patterns of speciation within the genus suggest that oceanic currents, sea-level, and geological changes over time can act as either barriers or aids to dispersal in the pelagic environment. Further, we used population genomic data to examine evolution in the open ocean of a distinct lineage of Bolinopsis ctenophores from the North Eastern Pacific. Genetic information and morphological observations validated this as a separate species, Bolinopsis microptera, which was previously described but has recently been called B. infundibulum. We found that populations of B. microptera from California were in cytonuclear discordance, which indicates a secondary contact zone for previously isolated populations. Discordance at this scale is rare, especially in a continuous setting.

Cervical Spine Research Society-Cervical Stiffness Disability Index (CSRS-CSDI): Validation of a Novel Scoring System Quantifying the Effect of Postarthrodesis Cervical Stiffness on Patient Quality of Life.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The aim was to create and validate a novel patient-reported outcome measure (PROM) focusing on stiffness-related patient functional limitations after cervical spine fusion. SUMMARY OF BACKGROUND DATA: Cervical arthrodesis is a common treatment for myelopathy/radiculopathy, however, results in increased neck stiffness as a collateral outcome. No current PROM exists quantifying the impact of postoperative stiffness on patient function. METHODS: The Cervical Spine Research Society-Cervical Stiffness Disability Index (CSRS-CSDI) was created through a modified Delphi process. The resultant 10-item questionnaire yields a score out of 100 with higher scores indicating increased functional difficulty related to neck stiffness. Cross-sectional study of control and postoperative patients was completed for CSRS-CSDI validation. Retest reliability (intraclass correlation coefficient), internal consistency (Cronbach alpha), responsiveness (levels fused vs. CSRS-CSDI scores), and discriminatory validation (CSRS-CSDI vs. neck disability index) scores) were completed. RESULTS: Fifty-seven surgical and 24 control patients completed the questionnaire. Surgical patients underwent a variety of procedures: 11 (19%) motion preserving operations, nine (16%) subaxial 1-2 level fusions, seven (12%) subaxial 3-5 level fusions, five (9%) C1-subaxial cervical spine fusions, 20 (35%) C2-upper thoracic spine fusions, five (9%) occiput-subaxial or thoracic spine fusions. The questionnaire demonstrated high internal consistency (Cronbach alpha=0.92) and retest reliability (intraclass correlation coefficient=0.95, P <0.001). Good responsiveness validity with a significant difference between fusion cohorts was found ( P <0.001, rs =0.63). Patient CSRS-CSDI scores also correlated with neck disability index scores recorded ( P <0.001, r =0.70). CONCLUSION: This is the first study to create a PROM addressing the functional impact of cervical stiffness following surgical arthrodesis. The CSRS-CSDI was a reliable and valid measure of postoperative stiffness impact on patient function. This may prove useful in counseling patients regarding their expected outcomes with further investigation demonstrating its value in a prospective fashion.

Environmental differences in substrate mechanics do not affect sprinting performance in sand lizards (Uma scoparia and Callisaurus draconoides).

Running performance depends on a mechanical interaction between the feet of an animal and the substrate. This interaction may differ between two species of sand lizard from the Mojave Desert that have different locomotor morphologies and habitat distributions. Uma scorparia possesses toe fringes and inhabits dunes, whereas the closely related Callisaurus draconoides lacks fringes and is found on dune and wash habitats. The present study evaluated whether these distribution patterns are related to differential locomotor performance on the fine sand of the dunes and the course sand of the wash habitat. We measured the kinematics of sprinting and characterized differences in grain size distribution and surface strength of the soil in both habitats. Although wash sand had a surface strength (15.4±6.2 kPa) that was more than three times that of dune sand (4.7±2.1 kPa), both species ran with similar sprinting performance on the two types of soil. The broadly distributed C. draconoides ran with a slightly (22%) faster maximum speed (2.2±0.2 m s(-1)) than the dune-dwelling U. scorparia (1.8±0.2 m s(-1)) on dune sand, but not on wash sand. Furthermore, there were no significant differences in maximum acceleration or the time to attain maximum speed between species or between substrates. These results suggest that differences in habitat distribution between these species are not related to locomotor performance and that sprinting ability is dominated neither by environmental differences in substrate nor the presence of toe fringes.

Spinal Cord Injury Clinical Classification Systems: What Is Available and a Proposed Alternative.

Spinal cord injury (SCI) remains a challenging disease in terms of surgical decision-making and improving neurologic outcome. As we have now entered a new era founded on routine "big data" capture, more advanced and meaningful yet simplified SCI classification systems and outcome measurement tools would be helpful to determine the efficacy of potential therapeutics in future clinical trials and registries. The proposed classification herein focuses on gross sensorimotor, sacral function below the injured level via an easy-to-use scoring system yielding grades 1 to 4 of injury severity. Such an optimized SCI scoring system would enhance real-time analytics and offer superior outcomes modeling.

The Intradiscal Osteotomy: An Alternative Technique for Adult Spinal Deformity Correction.

Adult spinal deformity (ASD) correction has changed considerably since the initial description of a Smith-Petersen osteotomy (SPO), including pedicle subtraction osteotomies (PSO), and more minimally invasive techniques. Here, we introduce and describe the intradiscal osteotomy (IDO), a novel variation of Schwab type 3 and 4 osteotomies allowing pedicle and vertebral body preservation, and its advantages and disadvantages. After pedicle screw placement, the posterior elements (except pedicles) are removed from the appropriate vertebrae, including the superior/inferior articulating processes, laminae, and spinous processes. An osteotome is used to remove the posterior aspect of the superior and inferior endplate, followed by the entire disc, creating more working room for eventual cage insertion. After the careful release of the annulus, an intradiscal distractor is used to distract the endplates and allow interbody cage insertion as anteriorly as possible. Pedicle and vertebral body preservation allow increased fixation and endplate cage support, which lengthens the anterior column and acts as a fulcrum when compressing posteriorly to restore lordosis. By allowing for anterior and posterior column release, the IDO technique provides a feasible, all-posterior approach for the correction of fixed or flexible kyphoscoliotic curves. This technical report introduces and describes the IDO as an alternative method for thoracic and/or lumbar ASD correction. More studies are required to fully elucidate its outcome vs. complication profile compared to other deformity correction techniques.

The Central Cord Score: A Novel Classification and Scoring System Specific to Acute Traumatic Central Cord Syndrome.

BACKGROUND: Acute traumatic central cord syndrome (ATCCS) is the most common form of spinal cord injury in the United States. Treatment remains controversial, which is a consequence of ATCCS having an inherently different natural history from conventional spinal cord injury, thus requiring a separate classification system. We devised a novel Central Cord Score (CCscore), which both guides treatment and tracks improvement over time with symptoms specific to ATCCS. METHODS: Medical records of patients with a diagnosis of ATCCS were retrospectively reviewed at a single institution. The CCscore was devised based on signs, symptoms, and imaging findings we believed to be critical in assessing severity of ATCCS. Numeric values were assigned for distal upper extremity motor strength, upper extremity sensation, ambulatory status, magnetic resonance imaging cord signal, and urinary retention. RESULTS: We identified 51 patients with follow-up data; there were 17 cases of mild injury (CCscore 1-5), 23 moderate cases (CCscore 6-10), and 11 severe cases (CCscore 11-15). Patients treated surgically had significantly greater improvement in upper extremity motor scores and total CCscore only up to 3 months. In terms of timing of surgery, patients treated <24 hours after injury had significantly improved upper extremity motor scores and overall CCscores at last follow-up of ≥3 months. CONCLUSIONS: Based on these data and their alignment with past literature, the CCscore is able to objectively and specifically categorize the severity and outcome of ATCCS, which represents a step forward in the quest to determine the ultimate efficacy and timing of surgery for ATCCS.