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Accurate representation of spinal geometry is necessary in biomechanical modelling to properly understand the function of the spine. The objective of this study was to create a large database of image-derived digital spine surface models for geometric studies and computational biomechanics investigation. Computed tomography scan data was acquired from 60 asymptomatic subjects (30 males and 30 females). Subjects ranged in age from 20 to 68 with equal numbers selected in each 10-year age bracket. Three-dimensional geometric surface models were generated for each subject's spine. A series of distance measures were also computed for each vertebral body to assess variation in the population. Geometric measures were able to show the significant variation in vertebrae size and shape within the subject population and as a function of vertebral level, gender, and age. This database enables the biomechanical evaluation of the variation in spinal loads that occurs within the population due to geometry. [ABSTRACT FROM AUTHOR]

Multiple-level noncontiguous spinal fractures (MNSF) are spinal fractures that involve at least 2 sites and are characterized by the presence of one intact vertebra or intact functional spinal unit between the fractured vertebrae. MNSF account for 2.5–19% of all spinal fractures. MNSF are easily missed or have a delayed diagnosis in clinical practice and their treatment is more complex than that for single-segment spine fractures. In this article, the authors briefly summarize the advances in the etiology and mechanisms of MNSF, the identification of their involved sites and their classification, diagnosis, treatment, and prognosis. [ABSTRACT FROM AUTHOR]

Background: Antipsychotic drugs appear to be related to reduced bone mineral density (BMD). We conducted a narrative review to collect the available literature investigating the relationship between antipsychotic use and bone fragility. Methods: A review of the published literature was conducted and reported through PubMed/Scopus/Cochrane libraries. We included studies using any antipsychotic treatment where the bone metabolism, osteoporosis, and/or risk of fractures has been assessed. Results: After screening 1707 items, we finally included 15 papers. A total of 3245 initial patients were identified, of whom 1357 patients with a mean age of 43.8 years underwent antipsychotic treatment and were analyzed. The mean antipsychotic treatment duration of the treated group was 15.8 ± 13.9 years. Among the included studies, two reported a statistically significant difference in lumbar BMD reduction between the antipsychotic exposed group and the control group. Femoral neck BMD levels had been reported in four of the case–control studies; two reported a statistically significant difference in femoral neck BMD reduction between the antipsychotic exposed group and the control group. Conclusions: Prolonged use of antipsychotic treatment seems to be associated with an increased risk of reduced BMD, and, consequentially, with an augmented risk of bone fragility and fractures. This effect is not limited to vulnerable groups, such as those with significant medical comorbidities, the elderly, and postmenopausal women, but may also apply to anyone using antipsychotics in the long-term. Clinicians' awareness of antipsychotic prescriptions should optimize their potential while reducing this risk. [ABSTRACT FROM AUTHOR]

Pre-Pleistocene fossils of Anolis lizards from the mainland of the Americas are exceedingly rare: only two specimens referred to a single species have been described previously. Here we report on a third specimen, preserved (as are the other two) in Miocene amber from Chiapas, Mexico, and consisting primarily of the anterior vertebrae of the caudal sequence. Despite the fragmentary nature of the fossil, it preserves key osteological characters that permit confident referral to the Anolis clade and further suggest placement within the Dactyloa subclade in a clade of three extant species within the Anolis aequatorialis series. The Chiapan provenance of the fossil indicates that the geographic distribution of the Dactyloa clade (and possibly that of the A. aequatorialis series) extended considerably farther north during the Miocene. Although the new fossil represents a different part of the body than the two fossils representing the fossil species Anolis electrum, its inferred phylogenetic relationships are the same as one of the several possible phylogenetic relationships of that species and thus allow for the possibility that all three specimens belong to the same species. [ABSTRACT FROM AUTHOR]

The aim of this study was to quantitatively study the effect of anterior cervical discectomy and fusion (ACDF) on the risk of spinal injury under frontal impact. A head-neck finite element model incorporating active neck muscles and soft tissues was developed and validated. Based on the intact head-neck model, three ACDF models (single-level, two-level and three-level) were used to analyze the frontal impact responses of the head-neck. The results revealed that various surgical approaches led to distinct patterns of vertebral damage under frontal impact. For single-level and three-level ACDFs, vertebral destruction was mainly concentrated at the lower end of the fused segment, while the other vertebrae were not significantly damaged. For two-level ACDF, the lowest vertebra was the first to suffer destruction, followed by severe damage to both the upper and lower vertebrae, while the middle vertebra of the cervical spine exhibited only partial damage around the screws. Fusion surgery for cervical spine injuries predominantly influences the vertebral integrity of the directly fused segments when subjected to frontal impact, while exerting a comparatively lesser impact on the cross-sectional properties of adjacent, non-fused segments. [ABSTRACT FROM AUTHOR]

The study describes the anatomy vertebrae of the Common Carp (Cyprinus carpio; Linnaeus, 1758) using 3D micro-CT and Semiquantitative Elemental Microanalysis (EDX), which helps to understand the ontogeny and factors that determine the biomechanics of bones in wild fish. The study of Common carp vertebrae revealed a complex and heterogeneous structure, with a variety of components contributing to their function and stability. The vertebral bodies were composed of lamellar trabeculae and internal hollow spaces, while the neural and hemal arches were composed of bony trabeculae and connected by a lace-like structure. The results of EDX analysis demonstrated the presence of oxygen, nitrogen, sodium, carbon, magnesium, and chlorine, among others. The calcium to phosphorus ratio was within the ranges described in teleost, suggesting good bone health. The presence of magnesium, sodium, potassium, chlorine, and nitrogen is due to their essential role in different biological processes. In addition, a difference was observed between the trabeculae present in the vertebrae of the abdominal and caudal segments, suggesting a relationship between the density of each bone and its function. These findings contribute to the understanding of the structure and function of vertebrae in wild Common carp and may have implications for understanding the evolution of the vertebral column in fish in general. [ABSTRACT FROM AUTHOR]

Ewing sarcoma (ES) is a rare type of malignant bone tumor that arises from mesenchymal stem cells. It commonly occurs in the diaphysis and diaphyseal-metaphyseal portions of long bones, pelvis, and ribs, although any bone can be affected. A minority of the Ewing sarcoma also arise in soft tissues, and a primary tumor in the neck with metastasis is extremely uncommon. We are reporting the case of a 12-year-old female with a history of fever for 4 months and a neck mass for 3 months. Given the broad range of inflammatory and neoplastic etiologies, an extensive laboratory and imaging workup was conducted. Cervical lymph node biopsy for histopathology showed sheets of round blue cells consistent with the diagnosis of Ewing sarcoma in the neck, while a positive immunohistochemical assays for NKX2.2, and negative assay for PAX-5, TdT markers neurofilament, neuron-specific enolase, and S100 protein ruled out the alternative etiologies such as rhabdomyosarcoma and lymphoma. After surgical excision of tumor, chemoradiotherapy was initiated. Despite the typically benign nature of extraosseous Ewing tumors, they can rarely metastasize in less than 20% of cases, as exemplified by this rare case. Accurate diagnosis requires a combined clinic-radio-immunohistochemical approach, and general practitioners should be aware of this clinical entity in neck masses considering its variable clinical presentation and poor prognosis in certain patient's population. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to identify a relatively robust SUV for guiding clinical practice through quantitative measurement and comparison of various normalization methods based on the SUV of 99mTc-MDP in the normal spine and pelvis using an integrated SPECT/CT scanner. Methods: Between June 2017 and September 2019, a total of 500 oncology patients (mean age, 60.9; men, 66.0%) who underwent bone SPECT/CT scans with 99mTc-MDP were enrolled in this retrospective study. The mean SUV (SUVmean) of 4962 spinal and pelvic bones was calculated based on the patients' body weight (BW), lean body mass (LBM), bone mineral content (BMC), body surface area (BSA), and body mass index (BMI), defined as SUVbw, SUVlbm, SUVbmc, SUVbsa, and SUVbmi, respectively. The coefficients of variation (CoVs) of the aforementioned parameters were compared, and the correlation and multiple linear regression analyses were used to compare the extent to which these parameters were affected by sex, age, height, weight, BMI, and CT values. Results: The average SUVs in the normal spine and pelvis displayed a relatively wide variability: 4.573 ± 1.972 for SUVbw, 3.555 ± 1.517 for SUVlbm, 0.163 ± 0.071 for SUVbmc, 0.124 ± 0.052 for SUVbsa, and 1.668 ± 0.732 for SUVbmi. In general, SUVbsa had relatively lowest CoV (42.1%) in all vertebrae and pelvis compared with other SUVs. For correlation analyses, all SUVs displayed weak but significant correlations with age and CT values. For regression analyses, SUVbsa was influenced only by age, BMI, and CT values independently. The effects of these variables on SUVbsa were all smaller than those on conventional SUVbw. Conclusions: The SUVs of 99mTc-MDP in normal bone derived from quantitative bone SPECT/CT could serve as a reference for evaluating tumor bone metastasis, but it should be assessed on a site-specific basis. SUVbsa exhibited superior robustness among all the SUV normalization variations, indicating potential clinical applications. [ABSTRACT FROM AUTHOR]

Purpose: To establish an interleaved multislice variant of the averaged magnetization inversion‐recovery acquisitions (AMIRA) approach for 2D spinal cord imaging with increased acquisition efficiency compared with the conventional 2D single‐slice approach(es), and to determine essential prerequisites for a working interleaved multislice AMIRA approach in practice. Methods: The general AMIRA concept is based on an inversion recovery–prepared, segmented, and time‐limited cine balanced SSFP sequence, generating images of different contrast. For AMIRA imaging of multiple, independent slices in a 2D interleaved fashion, a slice loop within the acquisition loops was programmed. The former non‐selective inversions were replaced with slice‐selective inversions with user‐definable slice thickness. Results: The thickness of the slice‐selective inversion in 2D interleaved multislice AMIRA should be doubled compared with the manufacturer's standard setting to avoid an increased sensitivity to flow and pulsation effects particularly in the CSF. However, this solution also limits its practical applicability, as slices located at directly adjacent vertebrae cannot be imaged together. Successful interleaved two‐slice AMIRA imaging for a "reference" in vivo protocol with 0.50 × 0.50 mm2 in‐plane resolution and 8‐mm slice thickness is demonstrated, therefore halving its acquisition time per slice from 3 min down to 1.5 min. Conclusion: The investigated 2D interleaved two‐slice AMIRA variant facilitates spinal cord imaging that maintains similar contrast and the same resolution as the conventional 2D single‐slice AMIRA approach, but does so with a halved acquisition time. [ABSTRACT FROM AUTHOR]

Segmenting vertebrae and intervertebral discs from spinal MRI images is essential for the diagnosis and treatment of spinal diseases. However, the similarity among different vertebrae and discs, coupled with pathological variations, complicates the segmentation process of MRI images. To tackle this challenge, this study introduces an improved U-Net architecture for spinal MRI image segmentation. The encoder employs a Multi-scale Feature Fusion Module that integrates shallow and deep features through feature downsampling. Additionally, a Dual Attention Mechanism Module is embedded within both the encoder and decoder to enhance feature extraction capabilities. Furthermore, a Graph Convolutional Module is integrated to capture contextual relationships between vertebrae and intervertebral discs. To mitigate background interference, a Spinal Region Guidance Module is also proposed. Experiments conducted on the public dataset from the MRSpineSeg Challenge yielded an average Dice Similarity Coefficient of 85.11%. The results indicate that our proposed method not only improves the segmentation performance of spinal MRI images but also surpasses other models, which holds significant implications for the clinical diagnosis and treatment of spinal diseases. [ABSTRACT FROM AUTHOR]

The Colombian weasel, Neogale felipei, is a rare carnivoran known only from nine localities, eight in Colombia and one in Ecuador. Recent records have expanded our understanding of the distribution and threats that this mammal faces, but the species is still among the rarest Neotropical carnivores. Here, we present an update to the distribution of N. felipei based on a recent record obtained in the Cordillera Occidental (Western Cordillera) of Colombia, and information on internal and external morphology using noninvasive technique such as X-rays of museum preserved specimens. We also documented the presence of lice, Neotrichodectes minutus, which is the first documented ectoparasite of the species. With the new records, the species is currently known from 12 localities (11 in Colombia and one in Ecuador). We also present the first radiographic analyses for N. felipei and the obtained vertebral formula (49 total vertebrae) fits into the range reported for the species and other mustelids. Considering that the Colombian weasel is one of the rarest carnivores of the Neotropics, our work represents a noteworthy contribution to several aspects of the anatomy, distribution, and natural history of this rare carnivoran. [ABSTRACT FROM AUTHOR]

Background: Spinal stabilization in dogs is challenging, and improper implant placement can result in significant morbidity. Objectives were to evaluate reliability of a ball-tipped probe for detection of breached versus non-breached pedicle drill tracts in a canine large breed cadaveric model. CT scans obtained from T6 to sacrum. Fifty-six pedicles (T7-L7) were randomized to have 1 of 5 modified Zdichavsky drill tracts (non-breached, partial/full medial breach, partial/full lateral breach). All tracts were created using 3D-printed guides. Each pedicle was probed separately by 2 investigators in randomized fashion on 2 occasions, 2 weeks apart. Post-probing CT grading of tracts was performed by one investigator, blinded to probing results. Specificity, sensitivity, positive (PPV) and negative (NPV) predictive values and times to assign grade were compared between surgeons. Results: CT identified 43 non-breached tracts, 7 medial and 5 lateral breaches. One tract was excluded because of guide misplacement. Specificity was 90.1%. PPV for detection of medial and lateral breaches was 80.0% and 57.1%. Sensitivity for medial (grade 2a/2b) and lateral (grade 3a/3b) breaches was 100.0% and 80.0%. NPV was 98.8%. Overall median time to assign grade with probe was 37.5–59.5 s. Both surgeons had very good intraobserver agreement (k,0.823 and 0.812). Interobserver agreement for round 1 was good (k,0.674) and good-to-very good for round 2 (k,0.800). Conclusions: Use of a ball-tipped probe is associated with excellent specificity, excellent sensitivity to detect medial breaches, and good sensitivity to detect lateral breaches. This technique may be useful to confirm integrity of pedicle screw/pin tracts in dogs. [ABSTRACT FROM AUTHOR]

Purpose: Vertebral body tethering (VBT) is a new growth-modulating surgery for adolescent idiopathic scoliosis (AIS) requiring a distinct skillset and intraoperative setup. We compared perioperative details and outcomes of VBTs performed in a public pediatric orthopedic hospital and a general private hospital setting. Methods: We identified all patients receiving VBT for AIS from 1/2020 to 12/2023 with ≥ 6 months post-operative follow-up, with surgeries performed by the same senior surgeons. Clinical, radiological, and surgical details were retrieved. Results: 24 VBTs were performed in the private setting and 16 in the public setting. Average age at operation was 11.9 ± 1.1 at a Sanders staging of 3.8 ± 1.2 when the major curve Cobb angle was 50.5 ± 8.0°. Tethered curves were most often thoracic in location (23/40) followed by thoracolumbar/lumbar curves (10/40) and double curve tethers (7/40). Overall correction ratio of 68.0 ± 19.0% was achieved. Time from booking to operation (82.2 ± 39.2 vs 63.1 ± 34.4 days, p = 0.112) and operation time (310 ± 86.4 min vs. 289 ± 87.4 min, p = 0.054) were longer in the public and private setting respectively but failed to reach statistical significance. Time to chest drain removal (1.5 ± 0.8 vs. 3.5 ± 1.7 days, p < 0.001) and length of stay (4.3 ± 0.9 vs. 6.6 ± 1.8 days, p < 0.001) were significantly shorter in the private setting, whilst complication rates remained similar (7/24 vs. 3/16, p = 0.456). Conclusion: Expertise, resource availability, and costs differ in the public and private healthcare setting. With regards to VBT, the conditions for referral and surgical outcomes remained similar. Earlier drain removal and discharge for patients managed in the private setting was not associated with an increase in complication rate. [ABSTRACT FROM AUTHOR]

Background: Adult cervical deformity (ACD) surgery is more frequently being performed in frail patients. Although surgical outcomes are largely successful, there remains significant risk of poor outcomes. The ideal length of fusion constructs in these patients remains debatable. Methods: Patients undergoing cervical fusion for ACD with lower instrumented vertebra (LIV) at T4-or-above, with clinical and radiographic data from baseline (BL) to 2 years (2Y) were stratified by CD-modified frailty index into not frail (NF), frail (F) and severely frail (SF) categories. Deformity was classified by Kim et al. criteria. Means comparisons tests were used to assess differences between both groups. Logistic regression analyses were used to analyze associations between frailty categories, lower instrumented vertebra (LIV) and outcomes. Results: 286 patients (Age: 57.3 ± 10.9 years, BMI: 28.9 ± 6.4 kg/m2, CCI: 0.84 ± 1.26). 47% of patients were female. 32.2% of patients were NF, 50.3% F and 17.5% SF. By deformity, 66% were focal kyphosis (FK), 12% were flatneck, and 22% were cervicothoracic. Only FK type differed between NF and F/SF patients (39.2 vs 73.6%, p = 0.005). At baseline (BL), differences in age, BMI, CCI and deformity were not significant. F/SF patients had longer LOS (p = 0.018) and higher rates of distal junctional kyphosis/failure (DJK/F) at 2 years. Controlling for baseline disability, F and SF patients were more likely to experience poor outcomes at 2 years with C7 compared with more distal LIVs. The risk for poorer outcomes was not significant when comparing LIVs within the upper thoracic spine. Similar trends were seen performing sub-analyses specifically comparing F vs SF patients. Conclusions: Frail patients are at risk for poor outcomes following ACD surgery due to their comorbidities. These patients appear to be at even greater risk for poor outcomes with a lower instrumented vertebra proximal to T1. [ABSTRACT FROM AUTHOR]

Background: During the day-night cycle, gravity and applied stress to the body mass and spine causes a decrease in body height, which is restored overnight. This diurnal spine length variation has not yet been quantified during radiotherapy. Therefore, we aimed to quantify diurnal spine length variation on cone beam CTs (CBCTs) of pediatric patients (< 18 years) who underwent radiotherapy. Methods: For this retrospective study, we included 32 patients (mean age 10.0, range 2.7–16.1 years) who received image guided radiotherapy between 2012 and 2018 in two institutes. Patients were included when they had two fractions per day, or when fractions were scheduled on varying time slots over the course of treatment. Daily CBCTs were registered to the planning CTs using two automatic registrations relative to the bony anatomy; one to vertebra T11 and one to vertebra L4. For each CBCT, the differences between the cranial-caudal (CC) position of the T11 and L4 vertebrae were calculated. To determine the diurnal spine length variation, the difference in vertebrae position between the morning and afternoon CBCTs was calculated. Furthermore, we investigated the possible correlation of diurnal spine length variation with the time slot differences (time interval) between CBCTs (Spearman's ρ). Results: Overall, the median spine length variation was -1.0 (range -3.9–0.1) mm, and we found a significant reduction in spine length over the day (p < 0.001) with substantial variations between patients. Time intervals between CBCTs ranging from 4.0 to 9.5 h were not correlated with spine length reduction (ρ=-0.01; p = 0.95). Conclusions: We found a small but significant reduction in spine length (vertebrae T11 to L4) over the course of day in pediatric patients undergoing radiotherapy, measured on CBCT imaging. Spine length reduction did not correlate with CBCT time intervals. However, our results indicate that diurnal spine length reduction could induce a setup error during treatment, and therefore should be considered in pediatric radiotherapy. [ABSTRACT FROM AUTHOR]

Background: Hidden blood loss (HBL) is a notable complication in spinal endoscopic procedures. This study aims to compare tissue damage and hidden blood loss between two minimally invasive spinal techniques: unilateral biportal endoscopic lumbar discectomy (UBE) and percutaneous endoscopic interlaminar discectomy (PEID). Furthermore, the study examines the risk factors contributing to hidden blood loss in each procedure. Patients and methods: A single-center retrospective cohort study was conducted on 86 patients who underwent unilateral biportal endoscopic lumbar discectomy (UBE) and 73 patients who received percutaneous endoscopic interlaminar discectomy (PEID) between January 2021 and December 2023.Demographic data, blood loss parameters, and serum levels of creatine kinase (CK) and C-reactive protein (CRP) were recorded. Pearson or Spearman correlation analyses were conducted to evaluate associations between patient characteristics and HBL. Additionally, multiple linear regression analysis was used to identify independent risk factors for HBL. Results: A total of 159 consecutive patients were included in this study, consisting of 83 females and 76 males. The average hidden blood loss (HBL) was 431.00 ± 160.52 ml in the UBE group and 328.40 ± 87.71 ml in the PEID group, showing a statistically significant difference (P < 0.05). Pearson or Spearman correlation analysis indicated that in the UBE group, HBL was associated with operation time, preoperative hematocrit (Hct), ASA classification, and paraspinal muscle thickness. In the PEID group, HBL was correlated with operation time, preoperative activated partial thromboplastin time (APTT), paraspinal muscle thickness, and the presence of diabetes (P < 0.05). Multiple linear regression analysis demonstrated a positive correlation between HBL and operation time in both groups (P < 0.05), identifying operation time as an independent risk factor for HBL. Furthermore, CRP and CK levels were generally lower in the PEID group compared to the UBE group, particularly on postoperative day 3 for CRP and postoperative day 1 for CK. Both total blood loss and hidden blood loss were significantly lower in the PEID group than in the UBE group. Conclusion: Compared to UBE, PEID shows superior results regarding surgical trauma, total blood loss, hidden blood loss (HBL), and postoperative hematocrit (Hct) reduction. Consequently, PEID is recommended as the treatment of choice for younger patients or those with compromised baseline perioperative conditions.Additionally, Hidden blood loss remains a critical factor, and surgical duration presents a shared risk in both procedures. [ABSTRACT FROM AUTHOR]

Vertebral bone quality (VBQ) is a promising new method that can improve screening for osteoporosis. The drawback of the current method is that it requires manual determination of the regions of interest (ROIs) of vertebrae and cerebrospinal fluid (CSF) by a radiologist. In this work, an automatic method for determining the VBQ is proposed, in which the ROIs are obtained using a trained neural network model. A large, publicly available dataset of sagittal lumbar spine MRI images with ground truth segmentations was used to train a BRAU-Net++ hybrid CNN–transformer neural network. The performance of the trained model was evaluated using the dice similarity coefficient (DSC), accuracy, precision, recall and intersection-over-union (IoU) metrics. The trained model performed similarly to state-of-the-art lumbar spine segmentation models, with an average DSC value of 0.914 ± 0.007 for the vertebrae and 0.902 for the spinal canal. Four different methods of VBQ determination with automatic segmentation are presented and compared with one-way ANOVA. These methods use different algorithms for CSF extraction from the segmentation of the spinal canal using T1- and T2-weighted image data and applying erosion to the vertebral ROI to avoid a sharp change in SI at the edge of the vertebral body. [ABSTRACT FROM AUTHOR]

Background: Age–specific normal measurements or specific size criteria for retropharyngeal lymph nodes in children have not been defined. Objective: We aimed to determine the normal measurements and distribution of retropharyngeal lymph nodes on three–dimensional magnetic resonance imaging (3–D MRI) in children. Materials and methods: In this retrospective study, we included 440 patients (213 girls) aged 0–17 years who were admitted to our center with seizures and headaches and underwent brain and neck MRI with T2–sampling perfection with application–optimized contrasts using different flip angle evolution sequences. We evaluated the number, laterality, and level distribution of lateral and medial group lymph nodes according to the skull base–cervical vertebrae. For both groups, we measured the short and long diameters of the largest lymph node in the axial plane and the craniocaudal diameter in the sagittal plane. The short/long diameter ratios and volumes were determined. Results: In 433 cases (98%), 1,554 lateral group lymph nodes were detected. Medial group lymph nodes were less common (7%). The lateral group was mostly bilateral, while the medial group was unilateral. Lateral group lymph nodes extended from the skull base–first cervical (C1) vertebral level to the C4, while the medial group extended from the C2 vertebral level to the C4. The mean axial short axis, axial long axis, and sagittal long axis diameters were 5.8 mm, 10.1 mm, and 15.5 mm for the lateral group and 3.8 mm, 7.6 mm, and 10.8 mm for the medial group, respectively. Conclusion: The findings of the study show that normally retropharyngeal lymph nodes are frequently seen in children and provide valuable information for lateral and medial lymph nodes depending on age. [ABSTRACT FROM AUTHOR]

The Triassic was a key period in the evolution of vertebrates, and reptiles in particular, giving rise to a plethora of successful lineages, some of which are still extant. One of the groups that flourished during the early Mesozoic were the tanysaurians (Archosauromorpha: Tanysauria). They had elongate neck vertebrae that in some genera reached extreme proportions. Here, we provide the first comprehensive description of the internal structure of these extraordinary elements, focusing on the famously bizarre Tanystropheus. Through computed tomography and sectioning, we were able to reveal some intriguing features comparable to those seen in pterosaurs and birds. However, contrary to what we see in pneumatic bones, cervicals of tanysaurians contain a singular voluminous cavity. This results in a cylindrical structure in these vertebrae, which likely provided durability, while contributing less to the weight of the neck. These insights are relevant for better understanding of a unique and extreme anatomy among tetrapods, which evolved as a result of very strict selection for some particular function. Importantly, our findings demonstrate that major modifications of the internal anatomy of vertebrae were not unique to derived avemetatarsalians (pterosaurs and dinosaurs), but more widespread among reptiles. [ABSTRACT FROM AUTHOR]

Recent research into the snake vertebral column has highlighted the importance of considering regionalization and its implications for the life history of snakes. Our research delves into the distinctions in vertebral column morphology and regionalization within the snake family Colubridae, comparing arboreal and terrestrial species. Our results provide significant support for dissociation between two pre-cloacal regions: the 'pre-atrial' (anterior to heart) and the 'post-atrial' (posterior to heart). Furthermore, the two ecological groups display distinct proportional compositions between the two pre-cloacal regions and the one post-cloacal region (caudal); arboreal species tend to possess a higher proportion of caudal vertebrae, whereas terrestrial species exhibit a higher proportion of post-atrial vertebrae. Our study reveals that the axial morphology of arboreal species is distinct from that of terrestrial species; however, this was not attributable to a convergent evolution process. By estimating the evolutionary history of vertebral number in each region between the ecological groups, we find each region has a unique pattern, further highlighting evolutionary disassociation between the regions. This study adds to the growing evidence on regionalization of the pre-cloacal snake vertebral column and underscores the importance in continuing to develop our understanding of snake evolution. [ABSTRACT FROM AUTHOR]

Background and Purpose: Spinal cord (SC) cross‐sectional areas (CSAs) assessed with MRI have proven to be extremely valuable imaging markers in several diseases. Among the challenges is the delineation of vertebral levels to determine level‐dependent changes in cord atrophy. With this study, we aimed to (1) test the hypothesis that there is proportionality in the position of the first six intervertebral discs and the length of the upper portion of the SC and (2) show that a proportionality approach can simplify the CSA assessment across vertebrae offering good reliability. Methods: Forty‐six volunteers underwent standard T2‐weighted and T1‐weighted cervical SC MRI acquisitions. The distance between the obex and the intervertebral discs (from C2‐C3 to T1‐T2) was measured on the T2‐weighted acquisitions of the entire cohort. In a test‐retest experiment on 12 subjects, the % disc position values were used to define vertebral levels, and a comparison was performed with manual vertebrae assignment in terms of mean CSA and its coefficient of variation. Results: The mean upper cord length for the cohort was 144.0 ± 13.1 mm. The discs' level % position in the upper cord was found to be fairly consistent, with standard deviations of 0.8%‐1.7%. The mean vertebral CSA obtained with the proportionality method was substantially equivalent to the manual approach in terms of mean CSA values and test‐retest reliability. Conclusions: With this study, we propose a proportionality method for the assignment of cervical SC vertebral levels that can simplify the processing of MRI datasets in the context of CSA measurements. [ABSTRACT FROM AUTHOR]

The aim of this article is to propose unsupervised classification methods for size-and-shape considering two-dimensional images (planar shapes). We present new methods based on hypothesis testing and the K-means algorithm. We also propose combinations of algorithms using ensemble methods: bagging and boosting. We consider simulated data in three scenarios in order to evaluate the performance of the proposed methods. The numerical results have indicated that for the data sets, when the centroid sizes change, the performance of the algorithms improves. In addition, bagging-based algorithms outperform their basic versions. Moreover, two real-world datasets have been considered: great ape skull and mice vertebrae references. These datasets have different configurations, such as multiple reference points and variability. Bagged K-means and boosted K-means methods achieved the best performance on the datasets. Lastly, considering the synthetic and real data, the bagged K-means proved to be the best method. [ABSTRACT FROM AUTHOR]

Background: Lumbosacral transitional vertebrae (LSTV) or lumbarization of sacral vertebrae and sacralization of lumbar vertebrae are congenital variations. These are associated with alterations in anatomy and biomechanics of spinal and paraspinal structures, which lead to low back pain (LBP). Aims and Objectives: This radiological study was designed to identify the prevalence of LSTV in patients presenting with LBP and to classify the anatomical variations in LSTV according to the Castellvi classification. Materials and Methods: This hospital-based, cross-sectional, observational cohort study was conducted in the Department of Radiodiagnosis, in different medical colleges and hospitals of West Bengal. The study was done on 1500 patients aged 20-75 years with a history of LBP. Antero-posterior and lateral lumbosacral radiographs were done to identify LSTV. Results: The present study in West Bengal shows that 24.1% of subjects had LSTV among LBP patients, Castellvi Type IIA (33.4%) being the most common anatomical variant, followed by Type IB (19.6%). Sacralization (22.3%) was found more common than lumbarization (1.8%). Conclusion: LSTV comprises almost one-fourth of cases of low back ache which can be easily diagnosed by simple radiograph. It has important implications for surgery in the lumbosacral region. [ABSTRACT FROM AUTHOR]

The upper cervical spine has a complex anatomical structure, making anterior surgical approaches challenging and prone to complications. This study aims to explore the use of bilateral submandibular incisions to provide safer and more convenient exposure of the upper cervical spine and to assess the feasibility of this approach for anterior surgical treatment of complex upper cervical diseases. From November 2019 to August 2021, three patients with malignant tumors of the upper cervical spine were subjected to an anterior–posterior combined approach for cervical tumor resection. The cohort consisted of one male and two females, aged between 41 and 51 years. The anterior approach began with a submandibular incision, followed by blunt dissection through the prevertebral muscles to expose the diseased vertebra. Subsequently, the diseased vertebra was excised, and either a titanium cage or a pre‐customized 3D‐printed artificial vertebral body was implanted anteriorly. Then, posterior fixation of the cervical spine was performed using pedicle screws to provide additional stability. Follow‐up ranged from 8 to 34 months. All patients experienced varying degrees of pain relief within 24 hours post‐operation. Frankel grading showed improvement by at least one grade in all three cases. Regular X‐ray and magnetic resonance imaging examinations revealed no tumor recurrence or involvement of adjacent vertebrae in the surgical area. The anterior bilateral submandibular horizontal incision approach offers comprehensive exposure of the anatomical structures of the upper cervical spine. This approach introduces a new option for the anterior treatment of upper cervical spine diseases. [ABSTRACT FROM AUTHOR]

Movement patterns may be a factor for manipulating the lumbar load, although little information is yet available in the literature about the relationship between this variable and intervertebral disc pressure (IDP). A finite element model of the lumbar spine (49‐year‐old asymptomatic female) was used to simulate intervertebral movements (L2–L5) of 127 asymptomatic participants. The data from participants that at least completed a simulation of lumbar vertebral movement during the first 53% of a movement cycle (flexion phase) were used for further analyses. Then, for each vertebral angular motion curve with constant spatial peaks, different temporal patterns were simulated in two stages: (1) in lumbar pattern exchange (LPE), each vertebral angle was simulated by the corresponding vertebrae of other participants data; (2) in vertebral pattern exchange (VPE), vertebral angles were simulated by each other. The k‐mean algorithm was used to cluster two groups of variables; peak and cumulative IDP, in both stages of simulations (i.e., LPE and VPE). In the second stage of the simulation (VPE), Kendall's tau was utilized to consider the relationship between different temporal patterns and IDPs for each individual lumbar level. Cluster analyses showed that the temporal movement pattern did not exhibit any effect on the peak IDP while the cumulative IDP changed significantly for some patterns. Earlier involvement in lumbar motion at any level led to higher IDP in the majority of simulations. There is therefore a possibility of manipulating lumbar IDP by changing the temporal pattern with the same ROM, in which optimal distribution of the loads among lumbar levels may be applied as preventive or treatment interventions. Evaluating load benefits, such as load, on biomechanically relevant lumbar levels, dynamically measured by quantitative fluoroscopy, may help inform interventional exercises. [ABSTRACT FROM AUTHOR]

Tuberculous spondylitis following percutaneous vertebroplasty or kyphoplasty is rare. In this, we report a rare case of tuberculous spondylitis diagnosed after percutaneous vertebroplasty (PVP). A 69-year-old female sought came to our department with a history of chest and back pain from the last two months accompanied by weakness in both lower limbs. The patient underwent two vertebroplasty procedures at a local hospital within two years for compression fractures of the lumbar and thoracic spine. Due to continuous lower back pain following PVP surgery, along with the worsening back pain weakness in both lower limbs over the past 2 months, the patient presented to our hospital for the treatment. Radiological imaging showed long bone destruction in the L1, L2, and T12 vertebrae, accompanied by the formation of numerous paraspinal abscesses. The serum T-SPOT test yielded a positive result. A sample was taken from a paravertebral abscess for TB DNA testing (GeneXpert MTB/RIF assay) under the guidance of CT, which demonstrated the patient was infected with a non-drug-resistant strain of TB. The patient underwent surgical treatment via a combined anterior and posterior approach. The histological examination of the excised tissue revealed evidence of tuberculosis, characterized by granulomatous inflammation and sheet necrosis. After taking anti tuberculosis drugs for 12 months, the patient recovered without any sequelae. Spinal tuberculosis and osteoporotic vertebral compression fractures are similar in clinical and radiological aspects. Spinal surgeons should consider the entity of this disease to avoid misdiagnosis or complications. After diagnosis of spinal tuberculosis after vertebral augmentation surgery, early surgical intervention and anti-tuberculosis treatment should be carried out immediately. [ABSTRACT FROM AUTHOR]

Background: The current study aimed to evaluate the bone union rate between infected vertebrae after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. Methods: This retrospective multicenter cohort study evaluated 75 patients of posterior fixation for thoracolumbar pyogenic spondylitis that have been recorded at six relevant institutions from January 2016 to December 2022. Data on age, sex, location of infected vertebrae, number of infected disks, comorbidity, Pola classification, number of vertebrae fixed according to surgery, implant failure requiring revision surgery, and distance according to the type of infected vertebrae after surgery were evaluated. Further, their association with postoperative bone union was investigated > 12 months postoperatively. Results: Finally, 40 patients were included in the study. In total, 32 (80%) patients achieved bone union at the infected vertebrae after minimally invasive posterior fixation without bone grafting. The mean duration from surgery to union was 10.7 months. Twenty-six (65%) patients initially achieved bone union at the lateral and/or anterior bridging callus. Patients with multiple-level infected disks (33%, 2/6 patients) had a lower bone union rate than those with a single-level infected disk (88%, 30/34 patients) (p = 0.0095). Conclusions: In 80% of patients, bone union at the infected vertebrae was achieved after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. A total of 65% of the patients achieved initial bone union at the lateral and/or anterior bridging callus. Moreover, patients with multiple-level infected disks had a low bone union rate. Hence, the treatment strategy should be cautiously considered. Trial registration: This study was registered retrospectively and all procedures used in this study including the review of patient records were approved by the institutional review board. [ABSTRACT FROM AUTHOR]

Background: This study aims to assess the diagnostic utility of vertebral CT value and CT value difference in distinguishing between fresh and old osteoporotic vertebral compression fractures (OVCF). Methods: A retrospective analysis was conducted on 118 patients with OVCF who underwent both MRI and CT examinations at our hospital. The nature of the fractured vertebra was determined according to MRI. The CT value of the fractured vertebrae and the mean CT value of the adjacent normal vertebrae were measured separately, and the differences between these values were calculated. Independent samples t-tests were used to compare CT value and CT value difference among all groups. The receiver operating characteristic (ROC) curve was employed to determine the optimal cut-off value for both CT value and CT value difference in differentiating fresh and old fractures. Results: The study included a total of 163 fractured vertebrae from 118 patients. The CT value of fresh fractured vertebrae was significantly higher than those of adjacent normal vertebrae, which was statistically different (P < 0.001). In contrast, the difference between CT value of old fractured vertebrae and those of adjacent normal vertebrae was not statistically significant (P > 0.05). There were significant differences in CT value and CT value difference between fresh fractured vertebrae and old fractured vertebrae (P < 0.001). The ROC curve analysis showed that the optimal cut-off value of CT value for fresh fractures and old fractures was 103.40 HU. The optimal cut-off value of CT value difference was 39.81 HU. Conclusion: Vertebral CT value and CT value difference offer a certain reference value for distinguishing between fresh and old OVCF. These parameters can serve as a rapid diagnostic tool when MRI is unavailable or impractical, aiding in the timely assessment of OVCF. [ABSTRACT FROM AUTHOR]

Primary vertebral lymphoma is an exceedingly rare entity. We hereby report a case of a 67-year-old male who presented to our department with fever, weight loss, and progressively worsening lower back pain radiating to the right hip. Physical examination showed pain on percussion of the dorsal and lumbar spine and tenderness on palpation of the right upper thigh area. The radiographic findings revealed numerous vertebral lesions with a right psoas abscess extending to the right upper thigh. Intravenous antibiotic therapy was initiated and the patient underwent an incision and drainage of the psoas abscess with a favourable outcome. However, given the suspicious imaging findings of the osseous lesions suggestive of malignancy, a vertebral biopsy was performed and yielded histo-pathological findings consistent with bone mantle cell lymphoma. To the best of our knowledge, this is the first case of an infected primary bone mantle cell lymphoma with multiple vertebral involvement. The diagnosis is challenging and can be confused with other diseases. [ABSTRACT FROM AUTHOR]

Copyright of Neurosurgery & Neurology of Kazakhstan is the property of National Centre for Neurosurgery JSC 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.)

Intraspecific variation in cetacean vertebral anatomy as a result of ageing, growth, and sexual dimorphism is poorly understood. Using 3D geometric morphometrics, we investigated allometric patterns, sexual dimorphism, and ontogenetic trajectories in the vertebral column of false killer whale (Pseudorca crassidens). Our data set includes thoracic, lumbar, and caudal vertebrae of 30 specimens, including neonates, juveniles, and adults of both sexes. Vertebral shape was significantly correlated with size within each region. Neonatal vertebral shape differed significantly from juveniles and adults, displaying ontogenetic shape change. Allometric and growth patterns of the vertebral regions, particularly of the lumbar region with the thoracic and caudal regions, differed significantly, which may influence the function and mobility patterns of the vertebral regions during different life stages. Using quantitative methods, we could not conclude that the Pseudorca vertebrae are sexually dimorphic. This study describes for the first time intraspecific vertebral patterns in a cetacean species across ontogenetic stages. Pseudorca individuals live in large pods and swim together, sharing the same swimming mode. The neonates have a more flexible column and swim less efficiently following their mothers to nurse. [ABSTRACT FROM AUTHOR]

Herein, we describe a novel posterior lumbar interbody fusion (PLIF) technique with annulus fibrosus (AF) release and the use of expandable cages (called "anterior-release PLIF" [ARPLIF]). In this technique, posterior column osteotomy (PCO) and AF release provide excellent intervertebral mobility. AF release involves circumferentially peeling off the AF above or below the endplate between the fixed vertebrae under radiographic guidance without cutting the AF and anterior longitudinal ligament. Subsequently, high-angle variable-angle expandable cages are used to simultaneously expand both sides before inserting the percutaneous pedicle screws and correcting to achieve good local lumbar lordosis. PCO and AF release achieve excellent intervertebral mobility. Intervertebral mobility and simultaneous expansion of both cages disperse the force on the endplates, reducing cage subsidence, and the high-angle cages facilitate high intervertebral angle creation. The novel ARPLIF intervertebral manipulation technique can promote good local lumbar lordosis formation. [ABSTRACT FROM AUTHOR]

Background: Anatomical variations of Sacral hiatus play a pivotal role in Caudal epidural block (CEB) anaesthesia injections. Hence correct Anatomical location of the hiatus is vital during successful CEB. The present study was undertaken to dissect out the morphometric variations of sacral hiatus among young adult Odisha population. Materials and Methods: The study was conducted with 101 normal, dry human sacrum bones for multiple metric and non-metric analysis. Digital vernier calliper was used for metric study including measure sacral dimensions like anteroposterior diameter, transverse diameter, length of sacral hiatus and distance between the apex to mid-point of an imaginary line joining both S2 foramina, distance between mid-point of base to the midpoint of an imaginary line joining both S2 foramina, distance between apex to the highest point of right-side lateral crest/superolateral crest which corresponds to right side posterior superior iliac spine, distance between apex to the highest point of left side lateral crest/superolateral crest which corresponds to left side posterior superior iliac spine and distance between right and left superolateral sacral crest. Results: The mean length of Sacral Hiatus was 22.36 ± 8.61 mm. The mean transverse diameter of Sacral Hiatus was 15.40 ± 2.17mm. The mean antero-posterior diameter of sacral hiatus at apex was 5.19 ± 1.36 mm. Inverted U shape was most common. Most common level of apex of sacral hiatus with respect to sacral vertebra had been 4th Sacral vertebra and most common location of base of sacral hiatus in relation to the level of sacral/coccygeal vertebra had been found to be 5th Sacral vertebra. Summary and conclusion: The anatomical knowledge of multiple metric and non-metric variations of sacral hiatus are important in CEB anesthesia contributing to improved success of the procedure. [ABSTRACT FROM AUTHOR]

Background: Despite numerous studies identifying risk factors for proximal junctional failure (PJF), risk factors for recurrent PJF (R-PJF) are still not well established. Therefore, we aimed to identify the risk factors for R-PJF following adult spinal deformity (ASD) surgery. Methods: Among 479 patients who underwent ≥5-level fusion surgery for ASD, the focus was on those who experienced R-PJF at any time or did not experience R-PJF during a follow-up duration of ≥1 year. PJF was defined as a proximal junctional angle (PJA) ≥28° plus a difference in PJA ≥22° or performance of revision surgery regardless of PJA degree. The patients were divided into 2 groups according to R-PJF development: no R-PJF and R-PJF groups. Risk factors were evaluated focusing on patient, surgical, and radiographic factors at the index surgery as well as at the revision surgery. Results: Of the 60 patients in the final study cohort, 24 (40%) experienced R-PJF. Significant risk factors included greater postoperative sagittal vertical axis (OR = 1.044), overcorrection relative to age-adjusted pelvic incidence-lumbar lordosis (PI- LL; OR = 7.794) at the index surgery, a greater total sum of the proximal junctional kyphosis severity scale (OR = 1.145), and no use of the upper instrumented vertebra cement (OR = 5.494) at the revision surgery. Conclusions: We revealed that the greater postoperative sagittal vertical axis and overcorrection relative to age-adjusted pelvic incidence-lumbar lordosis at the index surgery, a greater proximal junctional kyphosis severity scale score, and no use of upper instrumented vertebra cement at the revision surgery were significant risk factors for R-PJF. Clinical Relevance: To reduce the risk of R-PJF after ASD surgery, avoiding under- and overcorrection during the initial surgery is recommended. Additionally, close assessment of the severity of PJF with timely intervention is crucial, and cement augmentation should be considered during revision surgery. Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

Summary: In this clinical commentary, the various pathologies occurring in the tail region of horses and foals are briefly summarised, followed by a discussion of angular deviations of the tail and the possibilities of their correction. [ABSTRACT FROM AUTHOR]

Summary: A 1‐week‐old Warmblood female foal was presented for evaluation of an angular deviation of the tail to the left. The foal was able to defaecate normally. Manual straightening of the tail was possible but not completely to its normal position. Radiology revealed a growth deformity of coccygeal vertebrae 6 and 7 (CoV). Spontaneous correction of the tail angle was not expected, and surgical correction was advised. At that moment, the owner decided to wait and the operation was postponed until further notice. After 10 weeks, surgical correction of the angular deviation was undertaken by transphyseal screw placement with hemicircumferential periosteal transection and elevation on the left side of both vertebrae as well as inserting a temporary external fixator in which the end was distracted. Three weeks after surgery, the pins were removed. At the follow‐up examination 12 months after initial surgery, the deviation was nearly corrected and reduced to ca. 10 degrees deviation, and the owner was satisfied with the obtained result. No loss of sensory or motor function had occurred. [ABSTRACT FROM AUTHOR]

Background: Automatic segmentation of vertebrae in spinal x‐ray images is crucial for clinical diagnosis, case analysis, and surgical planning of spinal lesions. Purpose: However, due to the inherent characteristics of x‐ray images, including low contrast, high noise, and uneven grey scale, it remains a critical and challenging problem in computer‐aided spine image analysis and disease diagnosis applications. Methods: In this paper, a Multiscale Feature Enhancement Network (MFENet), is proposed for segmenting whole spinal x‐ray images, to aid doctors in diagnosing spinal‐related diseases. To enhance feature extraction, the network incorporates a Dual‐branch Feature Extraction Module (DFEM) and a Semantic Aggregation Module (SAM). The DFEM has a parallel dual‐branch structure. The upper branch utilizes multiscale convolutional kernels to extract features from images. Employing convolutional kernels of different sizes helps capture details and structural information at different scales. The lower branch incorporates attention mechanisms to further optimize feature representation. By modeling the feature maps spatially and across channels, the network becomes more focused on key feature regions and suppresses task‐irrelevant information. The SAM leverages contextual semantic information to compensate for details lost during pooling and convolution operations. It integrates high‐level feature information from different scales to reduce segmentation result discontinuity. In addition, a hybrid loss function is employed to enhance the network's feature extraction capability. Results: In this study, we conducted a multitude of experiments utilizing dataset provided by the Spine Surgery Department of Henan Provincial People's Hospital. The experimental results indicate that our proposed MFENet demonstrates superior segmentation performance in spinal segmentation on x‐ray images compared to other advanced methods, achieving 92.61 ± 0.431 for MIoU, 92.42 ± 0.329 for DSC, and 99.51 ± 0.037 for Global_accuracy. Conclusions: Our model is able to more effectively learn and extract global contextual semantic information, significantly improving spinal segmentation performance, further aiding doctors in analyzing patient conditions. [ABSTRACT FROM AUTHOR]

A new, distinctively short‐bodied giraffe catfish of Parauchenoglanis is described from the Ndzaa River, a small left‐bank tributary of the Mfimi‐Lukenie basin in the Central basin of the Congo River in the Democratic Republic of the Congo. The new species can be distinguished from all congeners by having 29 or fewer (vs. 33 or more) total vertebrae. It can further be distinguished from all congeners, except Parauchenoglanis zebratus Sithole et al., 2023 and Parauchenoglanis ngamensis (Boulenger 1911), by having 13 or 14 (vs. 16 or more) pre‐anal vertebrae. The species is endemic to the Mfimi River basin, where it has been collected mainly in blackwater tributaries. [ABSTRACT FROM AUTHOR]

The lissamphibian clade Gymnophiona includes approximately 220 recognized modern species known by the English vernacular as caecilians and characterized by their elongated and annulated bodies, without girdles or limbs. Fossils of caecilians are particularly rare and mostly limited to isolated vertebrae. Until now, only four bona fide Gymnophionomorpha species have been named based on fossils. Only one of these (Apodops pricei) is a crown-group caecilian, but its affinities with modern caecilians are uncertain because the material is limited to one damaged vertebra and is currently lost. Here we describe a new genus and species of caecilian from the Oligocene Tremembé Formation, Brazil, based on a partially preserved fossil skeleton (including elements of the skull and postcranium) that is damaged but still partly articulated. We investigated the fossil caecilian's anatomy using high-resolution microcomputed tomography, and then compared it to the osteology of modern species. We interpret the fossil as a member of Typhlonectidae, a family of caecilians well known for their aquatic and semi-aquatic lifestyles. This new record represents the first record for caecilians from the Oligocene and also the first fossil species confidently assigned to an extant caecilian family. [ABSTRACT FROM AUTHOR]

Background: The iconic freshwater cichlid fishes (Cichlidae) comprise about 1750 validly named species and hundreds more that are known, but not yet described and named. Cichlids are an important source of protein for millions of people on several continents, are model organisms in studies of evolution, speciation, ecology, development, behaviour and physiology and are popular as aquarium fishes. Yet, comparative studies of cichlid internal anatomy are rare. Even their osteology has not been taxonomically surveyed. The cichlid postcranial skeleton has been especially neglected. New information: Here, I provide the first survey in cichlids of the considerable variation in numbers of vertebrae, supraneurals and dorsal- and anal-fin supports (pterygiophores), as well as the patterns with which the pterygiophores insert between the neural or haemal spines. The study includes some 1700 specimens of nearly 400 cichlid species. Focusing on the largest subfamily, the African cichlids or Pseudocrenilabrinae, the survey furnishes data from species in all but one of its 166 genera. Limited data from species in the other cichlid subfamilies (Etroplinae, Ptychochrominae and Cichlinae) and from the related leaffishes, Polycentridae, are also presented. Key examples of pterygiophore insertion patterns from throughout the range of variation are illustrated and discussed. Detailed analytical tables and all raw data are provided in supplementary files. A bizarre specialisation in Cyprichromis is noted, evidently for the first time. Uniquely in this Lake Tanganyikan genus, five to seven anal pterygiophores are abdominal in position, located anterior to the anal fin and inserting toward or between successive pairs of pleural ribs. Taxonomic changes: The most speciose tribe of African cichlids, currently known as Haplochromini, is correctly called Pseudocrenilabrini. Based chiefly on the molecular phylogenetic findings of other workers, I propose four pseudocrenilabrine subtribes, one occurring in rivers and three endemic to Lake Malawi. I also re-assign the Lake Tanganyikan tribe Tropheini as another subtribe of Pseudocrenilabrini, in line with numerous molecular studies placing tropheines firmly within this tribe. The remaining genera of Pseudocrenilabrini remain incertae sedis in this tribe pending clarification of their phylogenetic relationships. The character complex here surveyed is a promising source of taxonomically and phylogenetically informative characteristics distinguishing or uniting cichlid taxa at multiple hierarchical levels, from species through subfamily. This reference set of novel character data can also provide information for palaeontological studies of African cichlids. These attributes are skeletal features potentially available for study in well preserved fossils and may help determine their correct taxonomic placement. [ABSTRACT FROM AUTHOR]

The Toarcian (upper Lower Jurassic) strata of the world-renowned Posidonia Shale of Central Europe have yielded diverse assemblages of marine vertebrates. Some of them, such as those of the Holzmaden area in southwestern Germany, are among the best-preserved specimens of Lower Jurassic vertebrate taxa. Here, we provide a reassessment of 'Plesiosaurus' bavaricus, a long-overlooked plesiosaur taxon from the Posidonia Shale of northern Bavaria (southern Germany), established based upon two isolated cervical centra and a caudal vertebra. The cervical material exhibits an intriguing character combination, providing evidence for the presence of a distinct plesiosaur taxon in the upper Lower Jurassic of the Posidonia Shale of Germany. Additionally, we report another isolated cervical vertebra, likewise from the Posidonia Shale of Bavaria, that shows striking similarities to the type cervicals of 'P'. bavaricus. Following our study of the Bavarian specimens, we hypothesise that, despite their substantial incompleteness, it seems likely that the material belonged to the same taxon, either species or a group of species, distinct from other plesiosaurs known from the Posidonia Shale. [ABSTRACT FROM AUTHOR]

We report and describe the first fossil of a blind snake (Scolecophidia, Serpentes) for Argentina. The fossil is a complete and isolated vertebra assigned to Epictia sp. (Leptotyphlopidae). Modern members of Leptotyphlopidae are common in South America, especially in Argentina. The fossil was recovered from the basal layer of an Early Holocene fluvial unit in Entre Ríos province, northeastern Argentina. In addition to its important contribution to the fossil record of South America, this scolecophidian specimen also represents one of the few fossils documented from the Southern Hemisphere. Furthermore, this study represents the first contribution to the knowledge of scolecophidian trunk vertebral morphology in Argentinian species. [ABSTRACT FROM AUTHOR]

A fragmentary maxilla and isolated vertebrae of a viperid snake were found in the Lower Pleistocene deposits of the Taurida cave, Crimean Peninsula. The snake is assigned to Vipera cf. renardi based on the morphology of the maxilla. This is the first unquestionable fossil record of the Vipera ursinii-renardi complex dispersed into Crimea earlier than previously supposed, already in the Early Pleistocene. [ABSTRACT FROM AUTHOR]

This study aims to introduce a robust numerical approach to simulate complex small‐scale mediums such as trabecular bone tissue in form of a cylindrical specimen taken from human vertebra. Consideration of previous related studies indicates that there are several challenges in utilizing standard finite element (FE) techniques for the analysis of such biomechanical structures. This is mainly due to their time‐consuming procedure required for generating geometry conforming meshes. In this regard, the finite cell method (FCM) is an interesting alternative because it is based on the concept of the fictitious domain technique in which underlying meshes do not need to conform to the boundary of the domain. Since the considered trabecular bone tissue consists of a complex small‐scale internal morphology, generating a FE mesh is rather complicated. So, the application of the FCM can be justified by overcoming the mentioned shortcomings of FE methods for this problem. Using FCM, it is possible to simulate the mentioned trabecular cylinder from vertebral body using higher order cells of regular shapes where the geometry is taken care of through the numerical integration. The input for the present numerical tool corresponding to the complex internal morphology of the proposed tissue is given by a high‐resolution microCT scan. The outcome of the FCM will be compared to results obtained by mechanical testing of the specimen. [ABSTRACT FROM AUTHOR]

Purpose: To examine if coronal deformity angular ratio (C-DAR) serves as a predictor for progression to surgical magnitude in patients with Adolescent Idiopathic Scoliosis (AIS) treated with thoracolumbar sacral orthosis (TLSO). Methods: Patients with AIS, prescribed a full-time TLSO, Cobb angle 20–40°, Risser 0–2, who wore the brace ≥ 12.9 h and reached skeletal maturity/surgery were included retrospectively. C-DAR was defined as the Cobb angle divided by the number of vertebrae in the curve, yielding a larger value in short curves. The association between C-DAR and the risk of progression to surgical magnitude (> 45°) was assessed. Secondly, we evaluated the association between pre-treatment Cobb angle and in-brace correction on the risk of progression to > 45°. Results: We included 165 patients with a mean Cobb angle of 30 ± 6°. Of these, 46/165 (28%) progressed ≥ 6° and 26/165 (16%) reached surgical magnitude at the end of treatment. C-DAR was a significant predictor for risk of progression to surgical magnitude with an OR of 1.9 (CI 1.2–2.9) per unit increase in C-DAR. A threshold value of 5.15 was established and demonstrated an OR 5.9 (CI 2.1–17.9) for curve progression to a surgical magnitude. Likewise, pre-treatment Cobb angle showed a significant OR 1.3(CI 1.2–1.4) per degree increase in Cobb, whereas in-brace % correction showed OR 0.96 (CI 0.93–0.98). Conclusion: C-DAR is an independent predictor for progression to a surgical magnitude in AIS patients treated with bracing. Patients with a higher C-DAR should be counseled to help set realistic expectations regarding the likelihood of curve progression despite compliance with brace wear. [ABSTRACT FROM AUTHOR]

Purpose: We defined sagittal S-line tilt (SSLT) as the tilt of the line connecting the upper instrumented vertebra and the lower instrumented vertebra. This study aimed to: (1) examine the correlation between SSLT and proximal junctional angle (PJA) change values, and (2) determine the cut-off value of SSLT with respect to proximal junctional kyphosis (PJK) occurrence. Methods: Eighty-six consecutive patients (81 female and 5 male; mean age: 15.8 years) with Lenke 5C AIS who underwent posterior selective spinal fusion. Pearson's correlation coefficients were used to examine the relationship between preoperative SSLT and changes in PJA from preoperative to 2 years postoperative. The impact of SSLT on PJK at 2 years after surgery was assessed using a receiver operating characteristic (ROC) curve. Results: We observed a moderate positive correlation between preoperative SSLT and change in PJA (R = 0.541, P < 0.001). We identified 18 patients (21%) with PJK at 2 years postoperative. Mean preoperative SSLT in the PJK group and the non-PJK group differed significantly at 23.3 ± 4.1° and 16.1 ± 5.0°, respectively (P < 0.001). The cut-off value of preoperative SSLT for PJK at 2 years postoperative was 18° in ROC curve analysis, with a sensitivity of 94%, specificity of 68%, and area under the ROC curve of 0.868. Conclusion: In selective lumbar fusion for AIS Lenke type 5C curves, preoperative SSLT was significantly correlated with PJA change from preoperative to 2 years postoperative. SSLT was a predictor of PJK occurrence, with a cut-off value of 18°. [ABSTRACT FROM AUTHOR]

Purpose: Previous work comparing ASD to a normative population demonstrated that a large proportion of lumbar lordosis is lost proximally (L1-L4). The current study expands on these findings by collectively investigating regional angles and spinal contours. Methods: 119 asymptomatic volunteers with full-body free-standing radiographs were used to identify age-and-PI models of each Vertebra Pelvic Angle (VPA) from L5 to T10. These formulas were then applied to a cohort of primary surgical ASD patients without coronal malalignment. Loss of lumbar lordosis (LL) was defined as the offset between age-and-PI normative value and pre-operative alignment. Spine shapes defined by VPAs were compared and analyzed using paired t-tests. Results: 362 ASD patients were identified (age = 64.4 ± 13, 57.1% females). Compared to their age-and-PI normative values, patients demonstrated a significant loss in LL of 17 ± 19° in the following distribution: 14.1% had "No loss" (mean = 0.1 ± 2.3), 22.9% with 10°-loss (mean = 9.9 ± 2.9), 22.1% with 20°-loss (mean = 20.0 ± 2.8), and 29.3% with 30°-loss (mean = 33.8 ± 6.0). "No loss" patients' spine was slightly posterior to the normative shape from L4 to T10 (VPA difference of 2°), while superimposed on the normative one from S1 to L2 and became anterior at L1 in the "10°-loss" group. As LL loss increased, ASD and normative shapes offset extended caudally to L3 for the "20°-loss" group and L4 for the "30°-loss" group. Conclusion: As LL loss increases, the difference between ASD and normative shapes first occurs proximally and then progresses incrementally caudally. Understanding spinal contour and LL loss location may be key to achieving sustainable correction by identifying optimal and personalized postoperative shapes. [ABSTRACT FROM AUTHOR]

Standard plain film medical radiographs often form a valuable line of evidence to identify individuals in large‐scale fatality events. While commonly available, chest radiographs present a challenge that their analysis is somewhat more involved and complex than radiographic records of other body regions. For example, chest radiographs concern subtler morphological varieties of smaller anatomical features across a larger number of skeletal elements in contrast to frontal sinus comparisons that concern a large, (often) single, highly variable void within one bone. This does not detract from or discount chest radiographs as useful identification aids, but it does demand additional prerequisite skills in radiographic interpretation to ensure valid conclusions are attained. When subjects deviate from standardized antemortem (AM) radiographic positions and/or the image quality decreases, the complexity of a chest radiograph comparison is elevated. Generally, the current body of forensic radiographic comparison literature infrequently addresses these more complex circumstances. In this paper, we use real‐world radiographic comparison reference images from a military DVI repatriation context to illustrate these factors and outline some procedures that enable these complexities to be easily recognized and appropriately addressed at case examination. A report for an exemplar case that concurrently highlights multiple factors is presented. For novices learning radiographic comparison methods, this case review saliently demonstrates: (1) why the AM reference radiograph(s) drive(s) the radiographic comparison procedure; (2) why care should be taken for correct positioning of the cervicothoracic junction in postmortem radiography of chest elements. [ABSTRACT FROM AUTHOR]

Copyright of Southern Clinics of Istanbul Eurasia is the property of KARE Publishing 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.)

In the domain of anatomy, some Chinese characters in anatomical terms possess distinctive morphological significance. Chinese characters evolved from pictographic characters, with some of these pictographs being created by ancient people based on their own body structure. This implies that the comprehension and depiction of the human body structure have been integral since the inception of Chinese characters, and this knowledge has been passed down and developed through the continued inheritance of Chinese characters. Even today, certain characters retain the appearance to reflect the shape of the human body structure. By examining the characters related to vertebrae, cranial fontanel and heart, we can find the unique and enduring link between Chinese characters and the fields of anatomy as well as Chinese traditional medicine. [ABSTRACT FROM AUTHOR]