Sacrum Research Articles

Deep-learning reconstructed lumbar spine 3D MRI for surgical planning: pedicle screw placement and geometric measurements compared to CT.

To test equivalency of deep-learning 3D lumbar spine MRI with "CT-like" contrast to CT for virtual pedicle screw planning and geometric measurements in robotic-navigated spinal surgery. Between December 2021 and June 2022, 16 patients referred for spinal fusion and decompression surgery with pre-operative CT and 3D MRI were retrospectively assessed. Pedicle screws were virtually placed on lumbar (L1-L5) and sacral (S1) vertebrae by three spine surgeons, and metrics (lateral deviation, axial/sagittal angles) were collected. Vertebral body length/width (VL/VW) and pedicle height/width (PH/PW) were measured at L1-L5 by three radiologists. Analysis included equivalency testing using the 95% confidence interval (CI), a margin of ± 1mm (± 2.08° for angles), and intra-class correlation coefficients (ICCs). Across all vertebral levels, both combined and separately, equivalency between CT and MRI was proven for all pedicle screw metrics and geometric measurements, except for VL at L1 (mean difference: - 0.64mm; [95%CI - 1.05, - 0.24]), L2 (- 0.65mm; [95%CI - 1.11, - 0.20]),and L4 (- 0.78mm; [95%CI - 1.11, - 0.46]). Inter- and intra-rater ICC for screw metrics across all vertebral levels combined ranged from 0.68 to 0.91 and 0.89-0.98 for CT, and from 0.62 to 0.92 and 0.81-0.97 for MRI, respectively. Inter- and intra-rater ICC for geometric measurements ranged from 0.60 to 0.95 and 0.84-0.97 for CT, and 0.61-0.95 and 0.93-0.98 for MRI, respectively. Deep-learning 3D MRI facilitates equivalent virtual pedicle screw placements and geometric assessments for most lumbar vertebrae, with the exception of vertebral body length at L1, L2, and L4, compared to CT for pre-operative planning in patients considered for robotic-navigated spine surgery.

Relationship between sacral-abdominal wall distance, movement performance, and spinal alignment in osteoporosis: a retrospective study

BackgroundAging is associated with muscle atrophy, as typified by sarcopenia. Loss of abdominal muscle strength can cause abdominal wall laxity. The purpose of this study was to investigate the relationship between the sacral vertebra–abdominal wall distance (SAD) and movement performance using a simple lateral spine X-ray image for measuring the SAD.MethodsIn this retrospective study, we included women aged ≥ 65 years who were attending the outpatient clinic for osteoporosis at our hospital. A total of 287 patients (mean age ± SD, 76.8 ± 7.1 years) with measured SAD were included in the analysis. Patients were divided into two groups based on SAD cutoff (160 mm) and age (75 years), respectively. The patients were examined using the two-foot 20 cm rise test, 3 m Timed Up and Go (TUG) test, two-step test, open-eyed one-leg standing time, and spinal alignment. Normally distributed data are expressed as means (standard deviations) and non-normally distributed data as medians (interquartile range), depending on the results of the Kolmogorov–Smirnov test. Student’s t-test and χ2 test were used for between-group comparisons. Regression analysis was performed with SAD as the objective variable. A two-sided p < 0.05 was considered statistically significant.ResultsThe shorter SAD group performed better in the two-step test, TUG test, and open-eyed one-leg standing time (p < 0.001) as well as in the two-foot 20 cm rise test (p < 0.01) compared to the longer SAD group. Spinal alignment was better in the shorter SAD group than in the longer SAD group, with a shorter sagittal vertical axis (p < 0.001), smaller pelvic tilt (p < 0.001), and greater sacral slope (p < 0.05).ConclusionSAD was associated with posterior pelvic tilt and movement performance parameters. In addition to testing for osteoporosis, movement performance parameters should be evaluated in women with osteoporosis who are aged ≥ 65 and have greater SAD (≥ 160 mm in this study). The SAD is a new assessment method, and further research is required to verify its validity and reproducibility. This is the first attempt to determine how age and SAD affect movement performance in older adults.

Vertebral formula and numerical variations in the spine of the Antarctic and southern South American penguins (Aves: Sphenisciformes)

Abstract The vertebral column in tetrapods consists of several constant regions, namely the cervical, thoracic, lumbar, sacral, and caudal regions. Each of these regions is characterized by a specific number of vertebrae, contributing to the overall vertebral formula. Supernumerary and/or missing vertebrae have only been sporadically mentioned for penguins, and the specific vertebral formula is only determined for some non-passeres orders. Variations in the anatomy and vertebral number of South American and Antarctic penguin species are evaluated here. Sixty-six specimens of Aptenodytes forsteri, Pygoscelis adeliae, P. antarcticus, P. papua, Spheniscus magellanicus, and Eudyptes chrysocome were examined to establish the vertebral formula for six South American and Antarctic species, reporting the type and frequency of the variations found in the generalized configuration. We found no intraspecific variation in respect of the number of cervical as well as cervicothoracic vertebrae in all penguin species studied. Intra- and interspecific variation occur in the thoracic, synsacral, and caudal regions comprising 6–7, 13–14 and 5–8 vertebrae, respectively. Particularly, the variations were found in the transitional zones between one region and another and/or between synsacral segments.

The effect of an ultrasound-guided sacral erector spinae plane block on the postoperative pain of lumbar discectomy: a randomized controlled trial.

Pain management is essential after discectomy, the surgical treatment for lumbar disc herniation. This study evaluated the effect of sacral erector spinae plane block (SESPB) versus standard analgesic methods on postoperative analgesia and opioid consumption in lumbar discectomy operations. Over 18 years of age, ASA 1-3 group, 54 patients undergoing elective lumbar discectomy were included in the prospective, randomized, controlled, double-blind, study. They were randomly divided into groups, SESPB and non-block (control). Both groups completed surgery under general anesthesia. At the end of the surgery, group SESPB received a bilateral 20 cc block with 0.25% bupivacaine at the level of the second sacral vertebra. Both groups received tramadol via a patient-controlled analgesia (PCA) device. The primary outcome was total opioid consumption in the first 24 hours after surgery. Pain assessment by Visual Analog Scale (VAS), rescue analgesic requirements, time to first rescue analgesic requirement and adverse effects were recorded 24 hours postoperatively. Total tramadol consumption was 168.8±143 mg (P<0.04) higher in the control group. The first six-hour VAS scores and the number of rescue analgesic users were lower in the SESPB group (P<0.01). The first rescue analgesic use time was 440±140.3 minutes in SESPB group and 47.5±116.1 minutes in control group (P<0.01). Nausea-vomiting was more frequent in the control group (P<0.01) and patient satisfaction was higher in the SESPB group (P<0.01). In lumbar discectomy surgery, ultrasound-guided SESPB provided adequate analgesia by reducing opioid consumption and pain scores without complications.

Overlooked Pain Assessment Records in Patients with Pressure Injuries During the COVID-19 Pandemic: A Retrospective Data Analysis.

During the COVID-19 pandemic, healthcare professionals focused on identifying the cause of hemodynamic instability in patients and may have neglected to assess pressure injury (PI)-related pain. Although pain is an early indicator of PI development, there has been no systematic evaluation of PI-related pain in patients. To review nurses' records of PI-related pain in patients who developed PIs during the COVID-19 pandemic. This retrospective, descriptive study included data from 510 patients at one hospital. Collected data included patient demographics (age, sex, diagnosis, and comorbidities), PI classification, and assessment of PI-related pain. Assessment data regarding PI-related pain included the characteristics of the pain, the type of analgesia (pharmacologic/nonpharmacologic) administered before and after PI management (debridement, dressing change, etc), the route of administration, and the frequency of pain assessment before and after analgesia. The mean age of the patients (60.4% men) was 28.96 (SD, 5.82) years, and the mean length of hospital stay was 26.15 (SD, 16.1) days. Overall, 43.1% of the patients were treated in the ICU, 68.0% were conscious, and 18.6% tested positive for COVID-19. Deep-tissue injuries occurred in 57.5% of patients, with 48.6% developing stage 2 PI. The sacral region was the most common area for PI development (44.8%). The mean duration of repositioning in patients with PI was 23.03 (SD, 5.4) hours. Only 0.40% of patients (n = 2) were evaluated for pain, and only one patient was assessed for pain before and after analgesia was administered. The findings suggest a lack of comprehensive evaluation and records concerning PI-related pain in patients with COVID-19.

Malignant Phyllodes Tumor of the Right Breast with Sacral Bone Metastasis- A Clinical Case from our Practice with A Literature Review

Phyllodes breast neoplasms are rarely diagnosed biphasic tumors that are benign, borderline, or malignant. We present a rare malignant phyllodes tumor in a 62-year-old woman with bone metastasis in the sacrum, presented 4 months after radical breast tumor surgery. Because of a severe pain syndrome, we performed intensity modulated radiotherapy with a high single dose of 8 Gy in two fractions, once a week. In this article we emphasize the difficult histopathological diagnosis, as well as the differential diagnosis, requiring immunohistochemistry of the two tumor components / epithelial and stromal/, as well as the clinical and pathological characteristics determining the malignant nature of the disease. In the presence of a soft tissue component of the bone metastasis, a biopsy with immunohistochemistry is required to prove the histopathological diagnosis of the distant metastasis. Distant metastases require complex treatment, including chemotherapy and palliative radiation therapy

Sacroiliac Joint Denervation-A Novel Approach to Target Sacral Lateral Branches: A Practical Approach.

Sacroiliac joint (SIJ) pain is a relatively common cause of low back pain. Percutaneous radiofrequency (RF) techniques for SIJ are limited to ablation of the posterior SIJ innervation. Different techniques have been described for SIJ radiofrequency ablation, including conventional thermal, cooled RF, pulsed RF, bipolar RF, and specialized tip RF needle (i.e., multi-tined); however, additional costs may limit these applications. This new technique for SIJ denervation uses anatomical landmarks and a single RF cannula. Two spinal needles are placed lateral to the posterior S1 and S2 sacral foramina; then, with caudal tilt we get a coaxial view of the sacral bone, we advance an 18-G curved 15-mm active tip RF cannula just lateral to the aligned finder needles. Ablation is performed, and then the RF cannula is retracted 2cm and ablation is repeated for a total of four lesions. The two spinal needles placed lateral to the posterior sacral foramina S1 and S2 guide the final needle in the posterior aspect of the sacrum, lateral to the sacral foramina, where the lateral sacral branches are located. We introduce a cost and time efficient technique to perform radiofrequency ablation of the sacral lateral branches using a single RF needle. This technique utilizes the sacrum's reliable anatomy and angulation and maximizes the surface area of the active tip lesioning. This technique creates a strip lesion lateral to the sacral foramina and reduces time and cost efficacy compared to several of the other techniques and/or commercially available special devices designed for sacroiliac denervation.

MRI-based synthetic CT for assessment of the bony elements of the sacroiliac joints in children

ObjectivesThe purpose of this study is to assess the equivalency of MRI-based synthetic CT (sCT) to conventional CT for sacroiliac joint bony morphology assessment in children.MethodsA prospective study was performed. Children who had (PET-)CT-scan underwent additional MRI. sCT-CT image quality was analyzed by two readers subjectively overall, semi-quantitatively in terms of cortical delineation, joint facet defects, growth plate fusion, ossified nuclei, lumbosacral transitional anomaly, and bony bridges, and quantitatively for disc space height, spinal canal width, and sacral vertebrae width and height. Cohen’s kappa and equivalence analyses with Bland–Altman plots were calculated for categorical and continuous measures respectively.ResultsTen patients were included (6 boys; aged 9–16 years; mean age 14 years). Overall sCT image quality was rated good. Semi-quantitative assessment of cortical delineation of sacroiliac joints, bony bridges, and joint facet defects on the right iliac and sacral sides showed perfect agreement. Correlation was good to excellent (kappa 0.615–1) for the presence of lumbosacral transitional anomaly, fusion of sacral growth plates, joint facet defect, and presence of ossified nuclei. sCT-CT measurements were statistically equivalent and within the equivalence margins (–1–1 mm) for intervertebral disc space height and spinal canal width.Intra- and inter-reader reliability was excellent for quantitative assessment (0.806 < ICC < 0.998). For categorical scoring, kappa ranged from substantial to excellent (0.615–1).ConclusionsCT appears to be visually equivalent to CT for the assessment of pediatric sacroiliac joints. sCT may aid in visualizing sacroiliac joints compared to conventional MRI, with the benefit that no ionizing radiation is used, especially important in children.Critical relevance statementMRI-based synthetic CT, a new technique that generates CT-like images without ionizing radiation, appears to be visually equivalent to CT for assessment of normal pediatric sacroiliac joints and can potentially assess structural damage as it clearly depicts bony cortex.Key points• MRI-based sCT is a new image technique that can generate CT-like images.• We found that sCT performs similarly to CT in displaying bony structures of pediatric sacroiliac joints.• sCT has already been clinically validated in the sacroiliac joints in adults.• sCT can potentially assess structural damage from erosions or ankylosis as it clearly depicts bony cortex.Graphical

Discussion on "Five zang-organs all can lead to low back pain, not only the kidney".

Low back pain (LBP) is the common disease in the department of acupuncture and moxibustion in hospital and is treated basically in terms of kidney deficiency. Through clinical observation and in association with classic literature, the authors proposes that the five zang-organs all can lead to LBP relevant to internal injury. Based on the analysis of typical cases, the authors expounds the nature of pain caused by each zang-organ and clarified the keys of the differentiation. LBP related to the liver is manifested mainly as lumbar soreness and distending pain, accompanied by the limited forward and backward extension of the lumbar vertebra. When the dysfunction of the heart and lung are involved, the hollow pain is dominant, combined with the weakness and emptiness feeling in the lumbar region. When LBP is caused by the dysfunction of the spleen, muscular pain is the chief complaint, combined with heaviness and soreness in the local, and the stiffness on palpation. When rooted at the kidney, LBP is manifested chiefly by dull pain, with deep location of illness, mostly around the lumbar sacral region.

A modified method for precise anastomosis during laparoscopic low anterior resection for rectal cancer: the first clinical experience and application

BackgroundThere is no criterion to guide and evaluate the anastomosis of laparoscopic low anterior resection (LAR). We developed a new technique for precise anastomosis. This study endeavored to evaluate the effectiveness and safety of this new technology.MethodsPatients with mid-low rectal cancer who underwent laparoscopic LAR in our department were enrolled retrospectively between January 1, 2021 and July 1, 2023. During the LAR, the distance between the sacral promontory and the rectal stump was measured and used to determine the length of the sigmoid colon, which was preserved for anastomose. The demographic characteristics and short-term outcomes were analyzed.ResultsForty-nine patients (26 men, 23 women) with low and middle rectal cancer were retrospectively enrolled in the study. The distance of the tumor from the anal verge was 6.4 ± 2.7 cm. The operative time was 193 ± 42 min. All patients underwent precise anastomosis, among which 12 patients underwent freeing of the splenic flexure of the colon. According to our criteria, there was no redundant or tense state of the colon anterior to the sacrum after the anastomosis. Only one patient had a postoperative anastomotic leak (Grade B). All 15 patients receiving neoadjuvant chemoradiotherapy underwent terminal ileostomy. No postoperative death occurred within 30 days of the surgery. The median follow-up time in our study was 12 months. One patient developed a single metastasis in the right lobe of the liver in the eighth month after surgery and underwent microwave radiofrequency ablation, which did not recur in the four months of postoperative follow-up, and the rest of the patients survived disease-free without recurrence of metastasis.ConclusionsPrecise measurement of the proximal colon of the anastomosis can ensure accurate and convenient colorectal anastomosis and this may be a technique worthy of clinical application. However, its effectiveness needs to be further verified in a multicenter clinical trial.

VertXNet: an ensemble method for vertebral body segmentation and identification from cervical and lumbar spinal X-rays

Accurate annotation of vertebral bodies is crucial for automating the analysis of spinal X-ray images. However, manual annotation of these structures is a laborious and costly process due to their complex nature, including small sizes and varying shapes. To address this challenge and expedite the annotation process, we propose an ensemble pipeline called VertXNet. This pipeline currently combines two segmentation mechanisms, semantic segmentation using U-Net, and instance segmentation using Mask R-CNN, to automatically segment and label vertebral bodies in lateral cervical and lumbar spinal X-ray images. VertXNet enhances its effectiveness by adopting a rule-based strategy (termed the ensemble rule) for effectively combining segmentation outcomes from U-Net and Mask R-CNN. It determines vertebral body labels by recognizing specific reference vertebral instances, such as cervical vertebra 2 (‘C2’) in cervical spine X-rays and sacral vertebra 1 (‘S1’) in lumbar spine X-rays. Those references are commonly relatively easy to identify at the edge of the spine. To assess the performance of our proposed pipeline, we conducted evaluations on three spinal X-ray datasets, including two in-house datasets and one publicly available dataset. The ground truth annotations were provided by radiologists for comparison. Our experimental results have shown that the proposed pipeline outperformed two state-of-the-art (SOTA) segmentation models on our test dataset with a mean Dice of 0.90, vs. a mean Dice of 0.73 for Mask R-CNN and 0.72 for U-Net. We also demonstrated that VertXNet is a modular pipeline that enables using other SOTA model, like nnU-Net to further improve its performance. Furthermore, to evaluate the generalization ability of VertXNet on spinal X-rays, we directly tested the pre-trained pipeline on two additional datasets. A consistently strong performance was observed, with mean Dice coefficients of 0.89 and 0.88, respectively. In summary, VertXNet demonstrated significantly improved performance in vertebral body segmentation and labeling for spinal X-ray imaging. Its robustness and generalization were presented through the evaluation of both in-house clinical trial data and publicly available datasets.

Evaluation of Sacrum Measurements in Healthy Individuals and Patients with L5-S1 Spondylolisthesis

Objective: In recent studies, the relationship between sacrum morphology and orientation and spondylolisthesis has gained importance. The present study aimed to compare the morphometry of the sacrum between patients with L5-S1 spondylolisthesis and healthy subjects on multidetector computed tomography (MDCT) images. Methods: In this study, abdominopelvic MDCT images of 191 individuals (age range 20-92 years; 101 males and 90 females; 56 patients diagnosed with L5-S1 spondylolisthesis and 135 healthy individuals) were retrospectively evaluated. In this study, the sacrum parameters (Intercornual distance (ICD), sacral hiatus length (LHS), anteroposterior diameter of hiatus at the apex of sacral hiatus(APCWHSA), sacral height (SH), sacral table angle (STA), sacral table index (STI), S1 superior angle (S1A), sacral slope(SS)) evaluated morphometric and morphological in healthy individuals and patients with L5-S1 spondylolisthesis. Kolmogorov–Smirnov test was used to test the normality, which is one of the parametric test assumptions, of the data. Results: Age parameter was found statistically significant higher in the patient group (p&lt;0.001). STA, S1A, SH, LHS and APCWHSA measurements were found to be significantly higher in the healthy group. (p&lt;0.001, p&lt;0.001, p=.008, p=.005, and p=.002, respectively). STI and ICD were found to be significantly higher in women in the healthy group (p=.031, p=.010), while SH parameter was found statistically significant higher in men in the healthy group (p=.007). SS was found statistically significant lower in the healthy group (p&lt;0.001). S1A, L5-S1 spondylolisthesis was found statistically significant higher than Grade 1, Grade 2 according to the degree of slippage (p=.045). Conclusion: The results of this study showed that sacral morphology is important in the development or at least progression of spondylolisthesis.

Modified island flap for basal cell carcinoma of the nasal apex

An 80-year-old female presented with an atrophic lesion in the area of the nasal apex, dating for the past 5-6 years. The lesion had a superficial telangiectasias and a pearly edge, measuring 1 cm in diameter. The patient denies painful sunburns in the past. Previous history of basal cell carcinomas located on the temporal and sacral regions. [...]

Interpretable machine learning model to predict surgical difficulty in laparoscopic resection for rectal cancer.

Laparoscopic total mesorectal excision (LaTME) is standard surgical methods for rectal cancer, and LaTME operation is a challenging procedure. This study is intended to use machine learning to develop and validate prediction models for surgical difficulty of LaTME in patients with rectal cancer and compare these models' performance. We retrospectively collected the preoperative clinical and MRI pelvimetry parameter of rectal cancer patients who underwent laparoscopic total mesorectal resection from 2017 to 2022. The difficulty of LaTME was defined according to the scoring criteria reported by Escal. Patients were randomly divided into training group (80%) and test group (20%). We selected independent influencing features using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression method. Adopt synthetic minority oversampling technique (SMOTE) to alleviate the class imbalance problem. Six machine learning model were developed: light gradient boosting machine (LGBM); categorical boosting (CatBoost); extreme gradient boost (XGBoost), logistic regression (LR); random forests (RF); multilayer perceptron (MLP). The area under receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity and F1 score were used to evaluate the performance of the model. The Shapley Additive Explanations (SHAP) analysis provided interpretation for the best machine learning model. Further decision curve analysis (DCA) was used to evaluate the clinical manifestations of the model. A total of 626 patients were included. LASSO regression analysis shows that tumor height, prognostic nutrition index (PNI), pelvic inlet, pelvic outlet, sacrococcygeal distance, mesorectal fat area and angle 5 (the angle between the apex of the sacral angle and the lower edge of the pubic bone) are the predictor variables of the machine learning model. In addition, the correlation heatmap shows that there is no significant correlation between these seven variables. When predicting the difficulty of LaTME surgery, the XGBoost model performed best among the six machine learning models (AUROC=0.855). Based on the decision curve analysis (DCA) results, the XGBoost model is also superior, and feature importance analysis shows that tumor height is the most important variable among the seven factors. This study developed an XGBoost model to predict the difficulty of LaTME surgery. This model can help clinicians quickly and accurately predict the difficulty of surgery and adopt individualized surgical methods.

Molecular and morphogenetic features of neurulation

Neurulation occurs by two different mechanisms, called primary and secondary neurulation. In humans, primary neurulation occurs along most of the rostrocaudal axis of the embryo, while secondary neurulation occurs caudally, only in the lower sacral and coccygeal regions. Primary neurulation is responsible for a change in the neural plate shape, the lateral edges of which rise and then converge at the dorsal midline to merge into a tube. Initially, the neural tube, formed as a result of primary neurulation, is open at both ends through the so-called rostral and caudal neuropores. These neuropores connect the inner part of the neural tube with the environment (amniotic cavity) and later (by the end of primary neurulation) are closed. During primary neurulation, the brain and spinal cord are formed up to the upper sacral region (up to the level of junction between S1 and S2 vertebral bodies), however, the most caudal part of this anatomical region (sacral-coccygeal division of the spinal cord, conus medullaris and filum terminale) is formed at secondary neurulation. In humans, secondary neurulation occurs due to elongation and cavitation of the caudal cell mass into the medulla, which then transforms into a secondary neural tube. Thus, the main differences between primary and secondary neurulation are that the neural plate folds and invaginates into the body of the embryo and separates from the surface ectoderm, forming an underlying hollow tube in primary neurulation. Mesenchymal cell сlusters form a dense cord that undergoes mesenchymal-epithelial transition and forms cavities and an empty tube during secondary neurulation to form the terminal part of the spinal cord. Conclusions. Understanding the detailed molecular and genetic mechanisms of each stage of neurulation is relevant due to widespread congenital neural tube defects, and only perfect knowledge on each aspect of neurulation and all possible factors of potential influence on it will help to develop modern options for influencing some of them, and probably, cause a decrease in neural tube congenital defects.

Pressure injury prevalence in critical care settings: An observational pre-post intervention study.

To explore pressure injury prevention practices and evaluate the impact of an educational intervention on PI prevalence before and after an educational intervention. A multi-centre observational study. Data were collected at two time points in May 2021 and April 2022 using a Qualtrics® online form. Two Registered Nurses at each site collected observational data at each time point by diagnosing and staging any identified pressure injuries as part of a prevalence study. Patients admitted to participating units were included. A total of 181 patients in critical care units were included at the two-time points. Pressure injury prevalence was 60.9% at the outset, with 52.9% hospital-acquired, 37.9% unit-acquired and 23.0% medical device-related. Post-intervention prevalence decreased significantly to 28.7%, including 21.3% hospital-acquired, 14.9% unit-acquired, and 8.5% medical device-related. Pressure injuries were prominent in the sacral region, head area, and heels. Stages I and II pressure injuries were the most common. Increased age and longer ICU stays are linked to a heightened risk of pressure injury development in critically ill patients, whereas higher haemoglobin levels show an inverse relationship with the development of both pressure injury and severe stages in the univariate analysis. The predictive models revealed that increased age and longer ICU stays are predictors for both pressure injury development and progression to severe stages, while Braden scores predict the likelihood of developing severe stages of pressure injuries. This study has identified a benchmark for pressure injury prevalence in critical care units in Saudi Arabia. The results demonstrate that pressure injuries can be prevented in critically ill patients when evidence-based education strategies are implemented. Pressure injuries are an important issue for critically ill patients and can be prevented with proper investments. Strategies to prevent pressure injuries from admission will result in fewer pressure injuries. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines and the Template for Intervention Description and Replication (TIDieR) checklist. No patient or public contribution.

Variation in the sacrum of phytosaurs: New evidence from a partial skeleton of Machaeroprosopus mccauleyi.

Phytosaurs are a group of Upper Triassic semi-aquatic archosauriform reptiles. Their variable skull morphology forms the foundation of our understanding of their relationships and paleoecology, while only a few studies have focused on demonstrating the existence of postcranial variation. The numbers of vertebrae in the sacrum are thought to vary from two, the plesiomorphic condition for archosauriforms, to three, with the addition of a sacralized dorsal (i.e., dorsosacral) vertebra. In this study, we demonstrate the presence of a sacralized first caudal (i.e., caudosacral) vertebra in a sacrum belonging to Machaeroprosopus mccauleyi. We rule out taphonomic distortion or pathology as explanations for the inclusion of this element in the sacrum, suggesting instead that it occurred through modifications of the same developmental processes that likely produced dorsosacral vertebrae in phytosaurs. Additionally, we show that a dorsosacral vertebra is common in phytosaur specimens from the Chinle Formation and Dockum Group of the southwestern United States and suggest that it may be widespread among phytosaurs. The addition of sacral vertebrae potentially aided adaptation to larger body sizes or more terrestrial lifestyles in certain taxa.

Different exposure times of flexion distraction technique in the L5-S1 distance and local pain of patients with chronic low back pain: A feasibility study

BackgroundLow back pain (LBP) is a worldwide public health problem. The flexion-distraction technique (FDT) has been considered to treat LBP. However, the adequate dosage and the treatment effects are not clearly understood. This feasibility study aimed to assess the effects of different exposure times with 5 and 10 min of the FDT on the L5-S1 distance and pressure pain threshold (PPT) of patients with chronic LBP. MethodsA two-arm, examiner-blinded, randomized controlled feasibility trial with participants with chronic LBP enrolled in an outpatient clinic. Participants were randomly assigned to FDT-T5 (5 min) or FDT-T10 (10 min). The distance between the L5 lamina and the sacral promontory, and the PPT at the L5 spinous process was measured before and immediately after FDT. Ultrasound imaging was used to measure L5-S1 distance, and the pressure algometry examined the PPT. Pre- and post-intervention data were compared between two groups by two-way analysis of variance (ANOVA) for repeated measures. We also calculated the intra- and inter-rater reliability of the L5-S1 measurement. ResultsSeventeen participants [10 (58.8 %) females, mean age 45 (±12) years] completed all procedures. Improvements in the intervertebral space [FDT-T5 mean change = 2.65 (95 %CI 1.45, 3.85) mm; FDT-T10 mean change = 1.88 (95 %CI -1.86, 5.63) mm] and decreases in PPT values [FDT-T5 mean change = −0.55 (95 %CI -1.35, 0.26) Kgf; FDT-T10 mean change = −0.79 (95 %CI -1.92, 0.34) Kgf] were observed, although there was no significant difference between the two groups for the distance between the L5 lamina and the sacral promontory (p = 0.595) or the spinous process L5 PPT (p = 0.672) after the intervention. Good reliability values were found for inter- and intra-rater measurements ranging between ICC = 0.81 to ICC = 0.88). ConclusionIn this feasibility trial, both groups showed an increased distance between L5-S1 and decreased the PPT in the L5 spinous process, indicating greater pain sensitivity after the intervention. These quantitative methods may measure distance and pain in definitive studies. Implications for practice•This is the first study to compare the distance between the L5 lamina and the sacral promontory after the flexion-distraction technique (FDT) using ultrasound imaging (USI).•The present study could not determine the effect of a particular time of exposure to FDT (FDT-T5 or FDT-T10 min).•Both groups (FDT-T5 and FDT-T10 min) increased the lumbar distance, corresponding to mobilization of the lumbar region.•Both groups presented decreased values of PPT in the L5 spinous process immediately after the technique.•A single session of FDT showed improvements in the distance between L5 and S1 and reduced L5 pressure pain threshold in the feasibility study.

The postcranial skeleton of Teyujagua paradoxa (Reptilia: Archosauromorpha) from the early Triassic of South America.

Teyujagua paradoxa is a remarkable early archosauromorph from the Lower Triassic Sanga do Cabral Formation, Brazil. The species was originally described from an almost complete skull and a few associated cervical vertebrae, and no further postcranial elements were known at that time. Additional fieldwork in the Sanga do Cabral Formation, however, was successful in recovering a fairly complete postcranial skeleton attributable to the holotype. Here, we describe this new postcranial material, which is composed of cervical, dorsal, sacral and caudal vertebrae, limbs, pectoral and pelvic girdles, ribs, and gastralia. The description of its postcranial skeleton makes T. paradoxa one of the best-known early-diverging archosauromorphs. The cladistic analysis performed after the scoring of postcranial data recovered T. paradoxa in the same position initially described, close to the node that defines the Archosauriformes. Teyujagua paradoxa shares morphological features with representatives of early-diverging archosauromorphs and archosauriforms, with certain traits demonstrating a mosaic of plesiomorphic and apomorphic character states. We also performed partitioned morphospace and disparity analysis to elucidate the morphological disparity and evolutionary patterns among archosauromorphs. Teyujagua paradoxa occupies a notable position, suggesting an intermediate morphology between early archosauromorphs and proterosuchids. Disparity estimates highlighted Pseudosuchia and Avemetatarsalia as having the highest median disparity, reflecting their diverse cranial and postcranial morphologies, respectively. These findings offer valuable insights into archosauromorph macroevolution and adaptation.

Axonal projection of the medullary expiratory neurons in the feline thoracic spinal cord

Expiratory neurons in the caudal ventral respiratory group extend descending axons to the lumbar and sacral spinal cord, and they possess axon collaterals, the distribution of which has been well-documented. Likewise, these expiratory neurons extend axons to the thoracic spinal cord and innervate thoracic expiratory motoneurons. These axons also give rise to collaterals, and their distribution may influence the strength of synaptic connectivity between the axons and the thoracic expiratory motoneurons. We investigated the distribution of axon collaterals in the thoracic spinal cord using a microstimulation technique. This study was performed on cats; one cat was used to make an anatomical atlas and six were used in the experiment. Extracellular spikes of expiratory neurons were recorded in artificially ventilated cats. The thoracic spinal gray matter was microstimulated from dorsal to ventral sites at 100-μm intervals using a glass-insulated tungsten microelectrode with a current of 150–250 μA. The stimulation tracks were made at 1 mm intervals along the spinal cord in segments Th9 to Th13, and the effective stimulating sites of antidromic activation in axon collaterals were systematically mapped. The effective stimulating sites in the contralateral thoracic spinal cord with expiratory neurons in the caudal ventral respiratory group (cVRG) occupied 14.4% of the total length of the thoracic spinal cord examined. The mean percentage of effective stimulating tracks per unit was 18.6 ± 4.4%. The distribution of axon collaterals of expiratory neurons in the feline thoracic spinal cord indeed resembled that reported in the upper lumbar spinal cord. We propose that a single medullary expiratory neuron exerts excitatory effects across multiple segments of the thoracic spinal cord via its collaterals.