Effect of different lumbar-iliac fixation and sacral slope for Tile C1.3 pelvic fractures: a biomechanical study.

BACKGROUND: Lumbar-iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4-L5/L5 unilateral LIF (L4-L5/L5 ULIF), bilateral LIF (BLIF), and L4-L5/L5 triangular osteosynthesis (L4-L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar-iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers. METHODS: Eight male fresh-frozen human lumbar-pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4-L5 ULIF, L5 TOS, L4-L5 TOS, and L4-L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed. RESULTS: The displacement of L4-L5/L5 TOS in the left-right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4-L5 and L5 ULIF was not significant. BLIF significantly limited left-right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS. CONCLUSIONS: This study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad-caudal direction, and BLIF enhanced stability in the left-right direction. L4-L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.

Anterior peri-sacroiliac joint osteotomy in the treatment of malunion and nonunion of complex pelvic ring fracture: techniques and preliminary results.

PURPOSE: To introduce anterior peri-sacroiliac joint osteotomy (APSJO) through the lateral-rectus approach (LRA) for treating pelvic fracture malunion and nonunion, and to evaluate the safety, feasibility, and potential effectiveness. METHODS: Data of 15 patients with pelvic fracture malunion and nonunion who underwent treatment by APSJO were selected and analyzed. The reduction quality was assessed using the Mears and Velyvis criteria, while the pre-operative and post-operative function was revealed by the Majeed scoring system. The British Medical Research Council (BMRC) grading system was recruited for the evaluation of lumbosacral plexus function. RESULTS: The average operative duration was 264.00 ± 86.75 min, while the intra-operative blood loss was 2000 (600, 3000) mL. Anatomical reduction was complete in three cases, satisfactory in ten cases, and unsatisfactory in two cases. Among the seven patients with lumbosacral plexus injury, the pre-operative Majeed grades were good in two cases, fair in two cases, and poor in three cases, while the post-operative Majeed grades were excellent in three cases, good in three cases, and fair in one case. Muscle strength recovered to M5 in two cases, M4 in three cases, and showed no recovery in two cases. The pre-operative Majeed grades were good in five cases, fair in two cases, and poor in one case of the series without lumbosacral plexus injury, while the post-operative Majeed grades were excellent in seven cases and good in one case. CONCLUSION: APSJO through LRA may be a feasible strategy for treating pelvic fracture malunion and nonunion with promising application.

Design and Application of an Acetabular Integrative Anatomic Plate: A Retrospective Study of 178 Cases with Complex Acetabular Fractures.

OBJECTIVE: As conventional plates require repeated pre-bending during surgery with poor matching, this study aimed to explore the design and application of an acetabular integrative anatomical plate (AIAP) via the lateral-rectus approach (LRA) in fresh complex acetabular fractures for the good reduction and fixation. METHODS: We designed an AIAP based on the anatomical morphology of the Chinese people. From March 2016 to September 2021, 178 patients with fresh complex acetabular fractures treated with an AIAP via the LRA were retrospectively analyzed. All patients were treated by the LRA under general anesthesia in a supine position. The fragments were well reduced and fixed by AIAPs. The operation time and intraoperative blood loss were recorded. All patients underwent reexamination of pelvic X-rays and CT scans and were followed up for over 1 year postoperatively. The reduction quality of fracture was evaluated according to the Matta criteria. The postoperative functional recovery was evaluated by modified Merle d'Aubigne-Postel scoring system. Statistics were analyzed by SPSS 25.0 (SPSS Inc., Chicago, IL, USA). RESULTS: All 178 patients went through the operation successfully. The time from injury to operation ranged from 5 to 21 days (8.7 ± 2.6 days). The operation time ranged from 35 to 150 min (75 ± 29 min). The intraoperative blood loss was from 250 to 1400 ml (440 ± 153 ml). According to the Matta score, the fracture reduction was evaluated as excellent in 131 cases, good in 31 cases, and poor in 16 cases, with an overall excellent and good rate of 91%. Four patients suffered wound fat liquefaction and healed after fresh dressing. All patients were followed up for 1 to 5 years without wound infection. All fractures were healed. At the last follow-up, the modified Merle d'Aubigne-Postel score results were evaluated as excellent in 125 cases, good in 26 cases, and fair in 27 cases, with an overall excellent and good rate of 84.8%. Postoperative complications included six cases of traumatic arthritis of the hips and two cases of femoral head necrosis. CONCLUSION: The LRA with an AIAP can help expose, reduce, and fix anterior and posterior columns as well as the quadrilateral area of the acetabulum, which is capable of improving the reduction quality of complex acetabular fractures and shortening surgical time and blood loss, thus reaching a good clinical efficacy.

GraphCpG: imputation of single-cell methylomes based on locus-aware neighboring subgraphs.

MOTIVATION: Single-cell DNA methylation sequencing can assay DNA methylation at single-cell resolution. However, incomplete coverage compromises related downstream analyses, outlining the importance of imputation techniques. With a rising number of cell samples in recent large datasets, scalable and efficient imputation models are critical to addressing the sparsity for genome-wide analyses. RESULTS: We proposed a novel graph-based deep learning approach to impute methylation matrices based on locus-aware neighboring subgraphs with locus-aware encoding orienting on one cell type. Merely using the CpGs methylation matrix, the obtained GraphCpG outperforms previous methods on datasets containing more than hundreds of cells and achieves competitive performance on smaller datasets, with subgraphs of predicted sites visualized by retrievable bipartite graphs. Besides better imputation performance with increasing cell number, it significantly reduces computation time and demonstrates improvement in downstream analysis. AVAILABILITY AND IMPLEMENTATION: The source code is freely available at https://github.com/yuzhong-deng/graphcpg.git.

Treatment of Anterior Dislocation of the Sacroiliac Joint via the Lateral-rectus Approach: Surgical Techniques and Preliminary Outcomes.

OBJECTIVE: Anterior dislocation of the sacroiliac joint (ADSIJ) is caused by strong violence, and because of its low morbidity, there are no standardized diagnostic and therapeutical guidelines at this moment. This study aims to explore the surgical techniques and preliminary outcomes of the lateral-rectus approach (LRA) for treating ADSIJ. METHODS: A retrospective study was conducted of 15 patients with ADSIJ from January 2016 to January 2021. The patients' age ranged from 1.8 years old to 57 years old (37 ± 18 years old). All patients underwent open reduction and internal fixation (ORIF) through the LRA. Eight patients were combined with lumbosacral plexus injury and underwent neurolysis during operation. Patients' fracture type, mechanism of injury, associated injuries, operation time and intraoperative bleeding volume were accessed by reviewing medical history. Quality of fracture reduction was evaluated with the Matta score. At 1-year follow-up, the functional rehabilitation was evaluated by the Majeed rehabilitation criteria. For those with lumbosacral plexus injury, the neuromotor function was evaluated using muscle strength grading proposed by the British Medical Research Council (BMRC) and recovery was recorded. RESULTS: All 15 patients underwent the operation successfully. The surgical time ranged from 70 to 220 min (126 ± 42 min), and the intraoperative blood loss ranged from 180 to 2000 mL (816 ± 560 mL). Eighty percent of the cohort (12/15) were rated as excellent and good in the Matta score for fracture reduction quality after operation without surgical incision-related complications. At 1-year follow-up, the overall excellent and good rate was 73.3% (11/15) according to the Majeed criteria, the neuromotor function recovered completely in six cases and partially in two cases according to the BMRC muscle strength grading, and the recovery of sensory function was evaluated as excellent in six cases, good in one case and poor in one case, with an overall excellent and good rate of 87.5%. CONCLUSION: The LRA can well expose the surrounding structures of the sacroiliac joint from the front, which helps surgeons reduce and fix the anterior dislocation of the sacroiliac joint under direct vision and effectively decompress the entrapment of the lumbosacral plexus to achieve better clinical efficacy.

A new classification for quadrilateral plate fracture of acetabulum.

BACKGROUND: Recently, quadrilateral plate (QLP) fractures of acetabulum have attracted increasing attention. However, evidence for the appropriate classification of QLP fractures is still lacking, making it difficult to understand and manage these fractures. This study aimed to introduce a new classification for QLP fractures and evaluate its reproducibility. METHODS: A series of 1101 consecutive patients with acetabular fractures from 8 level-I trauma centers were enrolled in this study. All patients underwent preoperative radiograph and computed tomography imaging. QLP fractures were identified and classified using the new and Judet-Letournel classification system. The inter- and intra-observer reliabilities (kappa coefficients, κ) of these two systems were investigated by 4 observers. Furthermore, surgical approaches and fixation methods for each fracture type are described. RESULTS: In total, 243 (243/1101, 22%) patients with QLP fractures were identified and included in this analysis. The mean κ value of the intra-observer reliability was 0.84 (range, 0.763-0.919) for the new classification, indicating excellent agreement, and the inter-observer reliability was 0.762 (range, 0.625-0.876), indicating substantial agreement. The values were 0.649 (range, 0.523-0.708) and 0.584 (0.497-0.646), respectively, according to the Judet-Letournel classification. Six cases (6/243, 2.5%) could not be classified using the Judet-Letournel classification. The selection of surgical approaches and fixation methods depends on the fracture type; however, an anterior intra-pelvic approach and buttressing fixation using the plate or screw are preferred for QLP fractures. CONCLUSION: This study presents a new classification for QLP fractures, showing higher intra- and inter-observer reliabilities than those obtained using the Judet-Letournel classification. This allowed us to obtain an in-depth and comprehensive understanding of QLP fractures. Additionally, the new classification might guide further studies on surgical strategies for QLP fractures. LEVEL OF EVIDENCE: Level II.

Posterior wall fractures of the acetabulum: treatment using an anatomical plate through direct posterior approach.

OBJECTIVES: This study was aimed to measure the application of W-shaped acetabular angular plate (WAAP) through direct posterior approach (DPA) on the reconstruction of acetabular posterior wall fractures when compared with reconstruction plates. PATIENTS AND METHODS: A retrospective study was performed on patients treated with the WAAP or reconstruction plates via the DPA. The intraoperative data of operative time, blood loss and radiation exposure times were recorded. Radiographs of the pelvis and CT scan were obtained within one week post-operation to assess the reduction quality. The clinical outcome was evaluated by the modified Merle d'Aubigne and Postel score. RESULTS: From May 2016 to October 2019, a total of 41 patients with simple acetabular posterior wall fractures were included in this study, 22 from the WAAP group and 19 from the reconstruction plates group. There were no significant differences between the two group in age, gender, time from injury to operation, cause of injuries, length of incision and follow-up time (P > 0.05). In comparison with the reconstruction plates group, the average operation time of the WAAP group was significantly shorter (46.1 ± 12.7 min vs 59.2 ± 17.4 min, P < 0.05), the average radiation exposure times were significantly less (2.3 ± 0.6 vs 3.6 ± 1.0, P < 0.001), the average blood loss was significantly less (240 ± 98.9 ml vs 301.1 ± 66.6 ml, P < 0.05). According to Matta radiology criteria and the modified Merle d' Aubigne and Postel score, no significant difference was observed between the two group, as for the quality of reduction and function outcomes. CONCLUSION: The application of WAAP through DPA showed satisfactory preliminary clinical outcomes, showing promise to be an alternative technique for the treatment of acetabular posterior wall fractures.

Investigation of pelvic symmetry: A systematic analysis using computer aided design software.

Objectives: This study aimed to investigate the symmetry of the Chinese pelvis. Methods: Computed tomography scan images of each of 50 Chinese pelvises were converted to 3D models and the left sides of the pelvises were reflected on Mimics software. Then, the reflected left side model was aligned with the right side using the closest point algorithm function of Geomagic software to perform symmetry analysis. The volume and surface area of either side of the pelvises were also calculated. The mean standard deviation (SD), the mean percentage of permissible deviations within the ±2 mm range, the percentage differences in volume and surface area were measured to compare pelvic symmetry. In addition, the distribution of pelvic bilateral symmetry associated with both age and sex were compared. Results: The mean SD was 1.15 ± 0.16 mm and the mean percentage of permissible deviations was 90.82% ± 4.67%. The deviation color maps showed that the specific areas of asymmetry were primarily localized to major muscle or ligament attachment sites and the sacroiliac joint surfaces. There was no significant difference between the bilateral sides of the pelvis in either volume or surface area. Additionally, no difference in any indexes was exhibited in relation to sex and age distribution. Conclusion: Our results demonstrated that the pelvis has high bilateral symmetry, which confirmed the potential of using contralateral pelvic models to create fully patient-specific and custom-made pelvic implants applicable for the treatment of fracture and bony destruction.

Data analysis guidelines for single-cell RNA-seq in biomedical studies and clinical applications.

The application of single-cell RNA sequencing (scRNA-seq) in biomedical research has advanced our understanding of the pathogenesis of disease and provided valuable insights into new diagnostic and therapeutic strategies. With the expansion of capacity for high-throughput scRNA-seq, including clinical samples, the analysis of these huge volumes of data has become a daunting prospect for researchers entering this field. Here, we review the workflow for typical scRNA-seq data analysis, covering raw data processing and quality control, basic data analysis applicable for almost all scRNA-seq data sets, and advanced data analysis that should be tailored to specific scientific questions. While summarizing the current methods for each analysis step, we also provide an online repository of software and wrapped-up scripts to support the implementation. Recommendations and caveats are pointed out for some specific analysis tasks and approaches. We hope this resource will be helpful to researchers engaging with scRNA-seq, in particular for emerging clinical applications.

[A multicenter retrospective study assessing pelvic unlocking closed reduction device for reducing unstable pelvic posterior ring disruption].

Objective: To explore the application value and effectiveness of pelvic unlocking closed reduction device for the treatment of unstable pelvic posterior ring disruption. Methods: A retrospective analysis of clinical data of 243 cases of unstable pelvic posterior ring disruption treated with pelvic unlocking closed reduction device in 13 orthopaedic trauma centers across the country between December 2018 and June 2020 was performed. There were 139 males and 104 females; the age ranged from 18 to 92 years, with an average age of 48.5 years. The cause of injury included 132 cases of traffic accident injuries, 102 cases of falling from height, and 9 cases of crushing injuries. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 5 cases of type 61-B1, 13 cases of type 61-B2, 32 cases of type 61-C1.1, 47 cases of type 61-C1.2, 89 cases of type 61-C1.3, 35 cases of type 61-C2, and 22 cases of type 61-C3. The time from injury to operation was 2-121 days, with a median of 10 days. Preoperative preparation time, installation time of unlocking closed reduction device, fracture reduction time, intraoperative fluoroscopy times, intraoperative blood loss, and surgical complications were recorded, and Matta scoring standard was used to evaluate the quality of fracture reduction. According to Matta evaluation results, the patients were divided into two subgroups: excellent-good group and fair-poor group. The differences in gender, age, time from injury to operation, AO/OTA classification, and perioperative clinical indicators were compared between the two groups, and the effects of baseline data and perioperative indicators on the quality of fracture reduction were studied. Results: Pelvic unlocking closed reduction device did not interfere with the display of the pelvic structure and fracture displacement direction during the intraoperative fluoroscopy, effectively correcting the displacement of the pelvic ring. The preoperative preparation time was 17-60 minutes, with an average of 30 minutes; installation time of unlocking closed reduction device was 10-32 minutes, with an average of 21 minutes; intraoperative fracture reduction time was 15-205 minutes, with an average of 49.2 minutes; intraoperative fluoroscopy times were 41-420 times, with an average of 132 times; intraoperative blood loss was 40-1 500 mL, with an average of 71.5 mL. The reduction quality of pelvic fracture was evaluated according to Matta score immediately after operation. The results were excellent in 153 cases, good in 61 cases, fair in 24 cases, and poor in 5 cases. The excellent and good rate was 88.1%. Further subgroup analysis showed that there was no significant difference in other indexes ( P>0.05) between the excellent-good group and the fair-poor group except for the time from injury to operation and AO/OTA classification ( P<0.05). Among them, the excellent-good reduction rate was 92.2% (119/129) in patients with injury-to-operation time less than 10 days, and the fair-poor reduction rate was 25.7% (9/35) and 40.9% (9/22) in patients with AO/OTA 61-C2 and 61-C3 types, respectively. There was no surgery-related complication due to the application of the pelvic unlocked reduction device, no secondary iliac fractures, vascular, or nerve injuries, and postoperative CT showed that all channel screws were located in the osseous channel. Conclusion: The pelvic unlocking reduction device can effectively help to reduce the unstable pelvic posterior ring and maintain reduction, meet the needs of different projection angles of pelvic fracture with intraoperative C-arm fluoroscopy. The system facilitate the operation of pelvic reduction and precise fixation.

Treatment of Delayed Acetabular Fractures by Periacetabular Osteotomy through the Lateral-Rectus Approach.

OBJECTIVE: There has been a controversy in the surgical approach for delayed acetabular fracture. The objective of the present study is to investigate the feasibility, surgical techniques, safety, and efficacy of periacetabular osteotomy using the single lateral-rectus approach (LRA) for the surgical treatment of delayed acetabular fracture. METHODS: The retrospective study included 22 patients (16 males and six females, with an average age of 45 years) with delayed acetabular fractures from June 2012 to June 2019. For all cases, periacetabular osteotomy was performed through the single LRA. Fracture classification, mechanism of injury, associated injury, time to surgery, operation time, intraoperative blood loss, and complications were recorded and analyzed. The quality of the reduction was assessed based on Matta radiographic criteria. Potential impact factors affecting the quality of reduction were analyzed. Functional outcome was evaluated at the final follow-up according to a modified Mere D'Aubigne-Postel scoring system for each patient. RESULTS: All patients were followed up for at least 12 months. The duration of surgery was 140 min on average (110-205 min) and the mean intraoperative blood loss was 1250 ml (500-2100 ml). According to Matta radiographic criteria, the accuracy of reduction was "anatomical" in seven patients, "imperfect" in 11 patients, and "poor" in four patients, with an excellent and good rate of 81.8%. The time to surgery in poor reduction group was significantly longer than anatomical or imperfect reduction group (p < 0.05). All the acetabular fractures united after 8-12 weeks. The average modified Merle D'Aubigne-Postel score evaluated at the final follow-up was 14.6 (6-18), and the clinical outcomes were rated as excellent in six patients, good in 10 patients, fair in four patients, and poor in two patients, with an excellent and good rate of 72.7%. There were two cases of osteonecrosis of the femoral head (9%). No other complication was found for all cases. CONCLUSION: The LRA is an effective and minimally invasive approach in the treatment of delayed acetabular fractures excluding posterior wall fracture and posterior dislocation.

Surgical Treatment of Vertical Shear Pelvic Fracture Associated with a Lumbosacral Plexus Injury through the Lateral-Rectus Approach: Surgical Techniques and Preliminary Outcomes.

OBJECTIVE: To examine the surgical techniques and preliminary outcomes of the lateral rectus approach (LRA) for treating vertical shear (VS) pelvic fracture associated with lumbosacral plexus (LSP) injury. METHODS: This study was a retrospective trial. From August 2010 to October 2017, 29 patients with VS pelvic fractures involving LSP injury who were treated with the LRA were included in this study. The patients were 18-61 years old, with a mean age of 36.2 years. All patients underwent neurolysis, open reduction, and internal fixation (ORIF) through the LRA. The fracture reduction was evaluated using the Matta criteria, and the neural recovery was evaluated by muscle strength grading proposed by the British Medical Research Council (BMRC). RESULTS: All 29 patients underwent the surgery successfully. The mean operating time was 155.2 ± 32.1 min (range: 105-220 min). The mean operative blood loss was 1021.4 ± 363.4 mL (range: 400-2000 mL). All patients were followed-up for at least 24 months (mean, 32.8 ± 13.5 months; range: 24-96 months). According to the Matta criteria, there were 17 excellent cases, nine good cases, and three fair cases in 29 patients. The ratio of excellent-to-good cases was 89.66%. According to the criteria of the Nerve Injuries Committee of the British Medical Research Council (BMRC), the recovery of nerve and muscle strength achieved to M5 (full recovery of neurological symptoms) was 14 cases, M4 (fine recovery of neurological symptoms), seven cases; M1, M2, and M3 (partial recovery of neurological symptoms), five cases, and M0 (no recovery of neurological symptoms), three cases. CONCLUSIONS: LRA is a safe and feasible surgical approach for treating VS pelvic fractures with LSP injury, which can be used to perform nerve exploration and release from the front, reduce the fracture, and fix it with the anterior iliac plates and/or sacroiliac screws.

Identification of safe channels for screws in the anterior pelvic ring fixation system.

BACKGROUND: Minimally invasive surgery for pelvic fracture using anterior ring internal fixator system is increasing gradually, and the way to insert the fixation screws in the fixation system is the key technical points of the method. However, there have been few studies on insertion of fixation screws for the anterior pelvic ring internal fixator system. OBJECTIVE: To identify safe channels for fixation screws in the anterior pelvic fixator system and provide the anatomical basis for insertion of fixation screws in clinical operation. METHODS: Screw insertion was simulated into a total of 40 pelvic finite element models as well as 16 fresh pelvic specimens, and the channel parameters were measured. RESULTS: Finite elements (male, female) include: screws in ilium: length 114.4 ± 4.1 and 107.6 ± 8.3 mm, respectively; diameter 11.7 ± 0.5 and 10.0 ± 0.6 mm, distance between screw and anterior inferior iliac spine: 5.5 ± 1.0 and 5.6 ± 1.0 mm, angle of coronal plane 55.8° ± 2.4° and 50.6° ± 3.1°, angle of sagittal plane 26.6° ± 1.0° and 24.5° ± 1.9° and angle of horizontal plane 64.9 ± 3.7 and 58.1 ± 3.1; screws in pubis: length 47.0 ± 2.0 and 39.8 ± 3.9 mm, diameter 7.1 ± 0.4 and 6.1 ± 0.4 mm. Specimens (male, female) include: distance between screw and anterior inferior iliac spine: 5.5 ± 0.5 and 5.6 ± 0.7 mm, angle of coronal plane 55.9° ± 1.3° and 50.7° ± 1.5°, angle of sagittal plane 26.7° ± 0.5° and 24.1° ± 0.9° and angle of horizontal plane 64.8° ± 0.6° and 58.8° ± 0.8°. In the comparison between female and male in each group, differences in distances between screws and anterior inferior iliac spine and median line of symphysis pubis (P > 0.05) were not statistically significant; differences in the remaining parameters were statistically significant (P < 0.05). CONCLUSIONS: If surgeons paid attention to sex differences, select screws of appropriate diameter and length and hold the insertion position and direction, screws in the anterior pelvic ring fixation system could be safely inserted.

scMelody: An Enhanced Consensus-Based Clustering Model for Single-Cell Methylation Data by Reconstructing Cell-to-Cell Similarity.

Single-cell DNA methylation sequencing technology has brought new perspectives to investigate epigenetic heterogeneity, supporting a need for computational methods to cluster cells based on single-cell methylation profiles. Although several methods have been developed, most of them cluster cells based on single (dis)similarity measures, failing to capture complete cell heterogeneity and resulting in locally optimal solutions. Here, we present scMelody, which utilizes an enhanced consensus-based clustering model to reconstruct cell-to-cell methylation similarity patterns and identifies cell subpopulations with the leveraged information from multiple basic similarity measures. Besides, benefitted from the reconstructed cell-to-cell similarity measure, scMelody could conveniently leverage the clustering validation criteria to determine the optimal number of clusters. Assessments on distinct real datasets showed that scMelody accurately recapitulated methylation subpopulations and outperformed existing methods in terms of both cluster partitions and the number of clusters. Moreover, when benchmarking the clustering stability of scMelody on a variety of synthetic datasets, it achieved significant clustering performance gains over existing methods and robustly maintained its clustering accuracy over a wide range of number of cells, number of clusters and CpG dropout proportions. Finally, the real case studies demonstrated the capability of scMelody to assess known cell types and uncover novel cell clusters.

Fracture Mapping of Both-Column Acetabular Fractures.

OBJECTIVES: To characterize the location and frequency of the fracture lines and comminution zones of both-column fractures using fracture mapping. METHODS: Both-column fractures were retrospectively reviewed in 4 Level 1 trauma centers. Mimics software was used to reconstruct the both-column fractures and simulate the fracture reduction. Then, the fracture lines and the intra-articular and extra-articular comminution zones were drawn on a 3-dimensional innominate bone template. The distribution of fracture lines and fracture fragments were also mapped on the two-dimensional template of the acetabulum. All the included patients were divided into low-variety group and high-variety group according to the anterior column fracture line above or below the anterior superior spine. The anatomical characteristics of the posterior wall fragment were also analyzed in these 2 groups. RESULTS: Seventy-eight patients with both-column fracture were included. The T type or inverted Y type main fracture lines divided the innominate bone into low-variety (n = 11) and high-variety (n = 67) both-column fractures. The extra-articular comminution zones are usually distributed between the posterior iliac fragment and anterior column fragment. High-variety type both-column fractures are usually combined with high and sharp posterior wall fragments, whereas low-variety type both-column fractures are usually accompanied by low and flat posterior wall fragments. The comminution zones in the acetabulum are mostly concentrated in the anterior and inferior parts of the acetabulum. CONCLUSIONS: The innominate bone is divided into 3 major parts in the both-column fracture, and the fracture center is located at the proximal of the acetabular dome. The both-column fractures are divided into low-variety and high-variety patterns. The location of the anterior column fracture determined the characteristics of the posterior wall fragment.

Clinical application of anterior ring internal fixator system combined with sacroiliac screw fixation in Tile C pelvic fracture treatment.

BACKGROUND: How to perform minimally invasive surgery for Tile C pelvic fracture is a major problem in clinical practice. We performed minimally invasive surgery for Tile C pelvic fracture using anterior ring internal fixator systems combined with sacroiliac screw fixation. OBJECTIVE: To investigate the advantages and efficacy of anterior ring internal fixator systems combined with sacroiliac screw fixation in the treatment of Tile C pelvic fracture. METHODS: From May 2017 to May 2020, 27 patients with Tile C pelvic fracture who underwent anterior ring internal fixator system combined with sacroiliac screw fixation (group A) and 21 patients with Tile C pelvic fracture who underwent plate-screw system combined with sacroiliac screw fixation (group B) were retrospectively analyzed. RESULTS: All 48 patients were followed up for more than 12 months, all fractures healed within 3-6 months. The operative time, intraoperative bleeding volume, blood transfusion volume, incision length, hospital stay, complication rate and Majeed score were 63.5 ± 10.7 min, 48.3 ± 27.9 ml, 0 ml, 4.5 ± 0.8 cm, 10.2 ± 2.7 d, 3.7% and 89.7 ± 4.6 points, respectively, in group A and 114.8 ± 19.1 min, 375 ± 315.8 ml, 266.7 ± 326.6 ml, 9.2 ± 3.9 cm, 20.9 ± 5.7 d, 23.8% and 88.7 ± 4.9 points, respectively, in group B. Combined excellent and good rates of the Matta evaluation and Majeed score were 100% in both groups. There were no significant differences in the Matta evaluation or Majeed score between the two groups (both P > 0.05), whereas the operative time, intraoperative bleeding volume, blood transfusion volume, incision length and hospital stay were significantly less in group A (all P < 0.05). CONCLUSION: An anterior ring internal fixator system combined with sacroiliac screw fixation can effectively treat Tile C pelvic fracture, and has advantages, including minimal invasiveness, simple operation, short operative time, safe and reliable features, fewer complications, short hospital stay and a good curative effect.

ROS-Eliminating Carboxymethyl Chitosan Hydrogel to Enhance Burn Wound-Healing Efficacy.

Overexpression of reactive oxygen species (ROS) can lead to chronic inflammation, which limits skin wound healing. Therefore, it is of great significance to develop materials that can locally control the adverse reactions caused by excessive ROS. In this research, an ROS-sensitive hydrogel with strong free radical scavenging ability was prepared by introducing the thione (Tk) group into carboxymethyl chitosan (CMCTS) hydrogel. CMCTS hydrogel was cross-linked by NH2-Tk-NH2 agent and loaded curcumin (Cur), which possessed favorable nontoxicity, water absorption, mechanical property, biodegradability, drug release behavior, the M2 phenotype, and inflammatory factor regulating the capacity of macrophages. It is worth noting that Cur@CMCTS-Tk hydrogel can significantly inhibit oxidative damage of human fibroblasts in the H2O2-induced microenvironment and protect their viability by reducing the production of intracellular ROS. In vivo, ROS-removing hydrogel effectively accelerated the process of wound healing and possessed good regenerative properties, including hair follicle formation, promotion of new blood vessel formation, and highly orderly arrangement of collagen fibers in the full-thickness skin burn defect rat model. Hence, we expect that the Cur@CMCTS-Tk hydrogel could be used for wound treatment and tissue regeneration due to the ability to scavenge excess ROS.

Biomechanical study of Tile C3 pelvic fracture fixation using an anterior internal system combined with sacroiliac screws.

BACKGROUND: How to perform minimally-invasive surgery on Tile C pelvic fractures is very difficult, and it is also a hot topic in orthopedic trauma research. We applied minimally-invasive treatment using an anterior internal fixator combined with sacroiliac screws. OBJECTIVES: To compare the biomechanical properties of different fixation models in pelvic facture specimens, using an internal fixation system or a steel plate combined with sacroiliac screws. METHODS: Sixteen fresh adult cadaver pelvic specimens were randomly separated into four groups named A, B, C, and D. The four groups were respectively stabilized using a two-screwed, three-screwed, or four-screwed anterior internal fixator or a steel plate with sacroiliac screws. All models were tested in both standing and sitting positions. Vertical loads of 600 N were applied increasingly. Shifts of bilateral sacroiliac joints and pubis rupture were measured. RESULTS: The shifts in sacroiliac joints and pubis rupture in the standing position were all less than 3.5 mm, and the shifts in the sitting position were all less than 1 mm. In the standing position, the results of shifts in the sacroiliac joints were group C < group D < group B < group A. For comparisons between A:B and C:D, P > 0.05. For comparisons between A, B:C, and D, P < 0.05. The results of shifts in pubis ruptures were group D < group C < group B < group A. In the comparison between C:D, P > 0.05; for comparisons between A:B, A:C, A:D, B:C, and B:D, P < 0.05. In the sitting posture, the results of shifts in the sacroiliac joints were group C < group D < group B < group A, and the shifts in the pubis ruptures were group D < group C < roup B < group A. For comparison between C:D, P > 0.05. For comparisons between A:B, A:C, A:D, B:C, and B:D, P < 0.05. CONCLUSION: Use of an anterior internal fixator combined with sacroiliac screws effectively stabilized Tile C3 pelvic fractures. The stability of specimens increased as the number of screws in the internal fixator increased.

Systematic analysis of binding of transcription factors to noncoding variants.

Many sequence variants have been linked to complex human traits and diseases1, but deciphering their biological functions remains challenging, as most of them reside in noncoding DNA. Here we have systematically assessed the binding of 270 human transcription factors to 95,886 noncoding variants in the human genome using an ultra-high-throughput multiplex protein-DNA binding assay, termed single-nucleotide polymorphism evaluation by systematic evolution of ligands by exponential enrichment (SNP-SELEX). The resulting 828 million measurements of transcription factor-DNA interactions enable estimation of the relative affinity of these transcription factors to each variant in vitro and evaluation of the current methods to predict the effects of noncoding variants on transcription factor binding. We show that the position weight matrices of most transcription factors lack sufficient predictive power, whereas the support vector machine combined with the gapped k-mer representation show much improved performance, when assessed on results from independent SNP-SELEX experiments involving a new set of 61,020 sequence variants. We report highly predictive models for 94 human transcription factors and demonstrate their utility in genome-wide association studies and understanding of the molecular pathways involved in diverse human traits and diseases.

CaMelia: imputation in single-cell methylomes based on local similarities between cells.

MOTIVATION: Single-cell DNA methylation sequencing detects methylation levels with single-cell resolution, while this technology is upgrading our understanding of the regulation of gene expression through epigenetic modifications. Meanwhile, almost all current technologies suffer from the inherent problem of detecting low coverage of the number of CpGs. Therefore, addressing the inherent sparsity of raw data is essential for quantitative analysis of the whole genome. RESULTS: Here, we reported CaMelia, a CatBoost gradient boosting method for predicting the missing methylation states based on the locally paired similarity of intercellular methylation patterns. On real single-cell methylation datasets, CaMelia yielded significant imputation performance gains over previous methods. Furthermore, applying the imputed data to the downstream analysis of cell-type identification, we found that CaMelia helped to discover more intercellular differentially methylated loci that were masked by the sparsity in raw data, and the clustering results demonstrated that CaMelia could preserve cell-cell relationships and improve the identification of cell types and cell subpopulations. AVAILABILITY AND IMPLEMENTATION: Python code is available at https://github.com/JxTang-bioinformatics/CaMelia. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.