Neuro-bone tissue engineering: emerging mechanisms, potential strategies, and current challenges.

The skeleton is a highly innervated organ in which nerve fibers interact with various skeletal cells. Peripheral nerve endings release neurogenic factors and sense skeletal signals, which mediate bone metabolism and skeletal pain. In recent years, bone tissue engineering has increasingly focused on the effects of the nervous system on bone regeneration. Simultaneous regeneration of bone and nerves through the use of materials or by the enhancement of endogenous neurogenic repair signals has been proven to promote functional bone regeneration. Additionally, emerging information on the mechanisms of skeletal interoception and the central nervous system regulation of bone homeostasis provide an opportunity for advancing biomaterials. However, comprehensive reviews of this topic are lacking. Therefore, this review provides an overview of the relationship between nerves and bone regeneration, focusing on tissue engineering applications. We discuss novel regulatory mechanisms and explore innovative approaches based on nerve-bone interactions for bone regeneration. Finally, the challenges and future prospects of this field are briefly discussed.

Comparison of Computer-Assisted Navigation and 3D Printed Patient-Specific Template for the Iliosacral Screw Placement.

BACKGROUND: Iliosacral screw insertion by computer-assisted navigation gradually became the main technique in some hospitals, but the expensive price limited the extensive application. But other techniques such as 3D printed template was used to place iliosacral screw as novel method. This study was to compare the efficiency of percutaneous iliosacral screw placement by using patient-specific template and computer-assisted navigation. METHODS: Total of 58 patients from September 2017 to September 2021 with sacral injury were treated operatively with percutaneous screw technique, which was selected for this retrospective analysis and divided into two groups (template and computer-assisted navigation). There were 31 patients in template group and 27 patients in computer-assisted navigation group. The surgical details (operation time, blood loss, number of screw placements, and number of fluoroscopies), complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. T-test and rank-sum test was used in this study. RESULTS: Operation time in template group was less (33.97 ± 16.61 < 60.31 ± 11.46 min, p < 0.01), but the preoperative preparation time was more (6.35 ± 1.60 > 5.41 ± 1.58, p < 0.05). The quality of reduction in both groups was no difference (p = 0.352). A patient was complicated with gluteal vessel injury in operation in navigation group, which was treated with ligation, but the same injury was not observed in template group. The related surgical data of patient with gluteal injury was ignored in statistical analysis. CONCLUSION: Both of the two techniques could improve surgical efficiency, the operation time in template was less than computer-assisted navigation group, but the preoperative preparation time was more.

Bulk RNA-seq and scRNA-seq reveal SLC7A11, a key regulatory molecule of ferroptosis, is a prognostic-related biomarker and highly related to the immune system in lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is the most common pathological subtype of lung cancer. Ferroptosis is an iron-dependent, non-apoptotic cell death mode, highly correlated with the tumorigenesis and progression of multiple cancers. Solute carrier family 7 member 11 (SLC7A11) maintains the anti-porter activity of cysteine and glutamate to regulate ferroptosis. We collected bulk RNA-seq and scRNA-seq from The Cancer Genome Altas and Gene Expression Omnibus databases. Then, we extracted the expression level of SLC7A11 to perform the differential expression analysis between normal tissues and LUAD tissues. Then, we applied survival, univariate, and multivariate Cox regression analyses to investigate the predictive value of SLC7A11 in LUAD. Gene set enrichment analysis was used to explore the underlying molecular mechanisms of SLC7A11 in LUAD. Finally, we analyzed the relationship of SLC7A11 to the immune status and the curative effect of immunotherapy. The expression level of SLC7A11 in LUAD tissues was markedly increased. The survival analysis, univariate and multivariate Cox regression analysis showed that SLC7A11 was a negative factor for the prognosis of LUAD patients. Gene set enrichment analysis revealed that several immune-related pathways were enriched in the low-level group. The lower SLC7A11 level has a better therapeutic effect of immunotherapy and less probability of immune escape and dysfunction. SLC7A11 was a prognostic-related biomarker and closely correlated with the immune status and therapeutic effect of immunotherapy in LUAD, which could be an effective biomarker for evaluating the prognosis and the therapeutic efficacy of immunotherapy.

Both-column Acetabular Fractures with Posterior Wall Involved can be Managed through Single Anterior Approach by Evaluation of Computer-assisted Virtual Surgery Technique.

OBJECTIVE: Posterior wall (PW) fractures were sometimes associated in both-column acetabular fractures. How to evaluate pre-operatively the necessity for the performance of the posterior approach was an issue to be solved. In order to solve this issue, the computer-assisted virtual surgery technique was used to evaluate if the involved PW in both-column acetabular fractures (BACF) should be managed through posterior approach and verify the feasibility of this method. METHODS: Data of a consecutive cohort of 72 patients with both-acetabular fractures from January 2012 to January 2020 was collected for retrospective study, of which 44 patients had concomitant acetabular PW fractures, and patients without PW fractures were labeled as the BCAF group. Computer-assisted virtual surgery technique was performed pre-operatively to evaluate the necessity for performance of posterior approach in 44 patients, and posterior approach was required if more than 3 mm of displacement was still present in the reduced 3D model. The 23 patients without treatment through posterior approach were labeled as the BCAF-PW- group, and the 21 patients with treatment through posterior approach were labeled as the BCAF-PW+ group. Operation-related and post-operative parameters were recorded. The quality of reduction and functional outcomes were assessed by the Matta scoring system and modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data between every two groups. Also, the one-way analysis of variance (ANOVA) was used to analyze data between the three groups. RESULTS: Comparing operation-related and post-operative parameters in the three groups, some PW fractures in both-column acetabular fractures could be ignored, and which could be evaluated pre-operatively for necessity of an additional posterior approach. Operative time (271.2 ± 32.8 mins) and intra-operative blood loss (1176.7 ± 211.1 mL) were significantly higher in the BCAF-PW+ group. The excellent/good of reduction (25/28 of the BCAF group, 21/23 of the BCAF-PW- group, 19/21 of the BCAF-PW+ group) and functional outcomes (24/28 of the BCAF group, 18/23 of the BCAF-PW- group, 18/21 of the BCAF-PW+ group) of three groups were similar. The incidence of complications, such as deep vein thrombosis (4/28 of the BCAF group >3/23 of the BCAF-PW- group >1/21 of the BCAF-PW+ group) and injury of lateral femoral cutaneous nerve (3/23 of the BCAF-PW- group >2/28 of the BCAF group >0/21 of the BCAF-PW+ group), was no significant difference. CONCLUSION: The partial both-column acetabular fractures with PW involvement could be managed through a single anterior approach without another posterior approach by evaluation of computer-assisted virtual surgery technique.

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.

Biomechanical study of different fixation constructs for anterior column and posterior hemi-transverse acetabular fractures: a finite element analysis.

BACKGROUND: To compare the biomechanical properties and stability, using a finite element model, of four fixation constructs used for the treatment of anterior column and posterior hemi-transverse (ACPHT) acetabular fractures under two physiological loading conditions (standing and sitting). METHODS: A finite element model simulating ACPHT acetabular fractures was created for four different scenarios: a suprapectineal plate combined with posterior column and infra-acetabular screws (SP-PS-IS); an infrapectineal plate combined with posterior column and infra-acetabular screws (IP-PS-IS); a special infrapectineal quadrilateral surface buttress plate (IQP); and a suprapectineal plate combined with a posterior column plate (SP-PP). Three-dimensional finite element stress analysis was performed on these models with a load of 700 N in standing and sitting positions. Biomechanical stress distributions and fracture displacements were analysed and compared between these fixation techniques. RESULTS: In models simulating the standing position, high displacements and stress distributions were observed at the infra-acetabulum regions. The degree of these fracture displacements was low in the IQP (0.078 mm), as compared to either the IP-PS-IS (0.079 mm) or the SP & PP (0.413 mm) fixation constructs. However, the IP-PS-IS fixation construct had the highest effective stiffness. In models simulating the sitting position, high fracture displacements and stress distributions were observed at the regions of the anterior and posterior columns. The degree of these fracture displacements was low in the SP-PS-IS (0.101 mm), as compared to the IP-PS-IS (0.109 mm) and the SP-PP (0.196 mm) fixation constructs. CONCLUSION: In both standing and sitting positions, the stability and stiffness index were comparable between the IQP, SP-PS-IS, and IP-PS-IS. These 3 fixation constructs had smaller fracture displacements than the SP-PP construct. The stress concentrations at the regions of quadrilateral surface and infra-acetabulum suggest that the buttressing fixation of quadrilateral plate was required for ACPHT fractures.

Finite element analysis of posterior acetabular column plate and posterior acetabular wall prostheses in treating posterior acetabular fractures.

BACKGROUND: The purpose of this study was to investigate the mechanical stability of the posterior acetabular column plate and different posterior acetabular wall prostheses used in treating posterior acetabular fractures with or without comminution. METHODS: The unilateral normal ilium was reconstructed, and a model of posterior acetabular wall fracture was established on this basis. The fracture fragment accounted for approximately 40% of the posterior acetabular wall. The posterior acetabular column plate and different posterior acetabular wall prostheses were also designed. Using static and dynamic analysis methods, we observed and compared the changes in the stress and displacement values of different models at different hip joint flexion angles under external forces. RESULTS: At different hip flexion angles, the stress of each model mainly fluctuated between 37.98 MPa and 1129.00 MPa, and the displacement mainly fluctuated between 0.076 and 6.955 mm. In the dynamic analysis, the nodal stress‒time curves of the models were nonlinear, and the stress changed sharply during the action time. Most of the nodal displacement‒time curves of the models were relatively smooth, with no dramatic changes in displacement during the action time; additionally, most of the curves were relatively consistent in shape. CONCLUSIONS: For simple posterior acetabular wall fractures, we recommend using a posterior acetabular column plate. In the case of comminuted posterior acetabular fractures, we recommend the use of a nonflanked posterior acetabular prosthesis or a biflanked posterior acetabular prosthesis. Regarding the method of acetabular prosthesis design, we propose the concept of "Break up to Make up" as a guide.

Endogenous Electric Field-Coupled PD@BP Biomimetic Periosteum Promotes Bone Regeneration through Sensory Nerve via Fanconi Anemia Signaling Pathway.

To treat bone defects, repairing the nerve-rich periosteum is critical for repairing the local electric field. In this study, an endogenous electric field is coupled with 2D black phosphorus electroactive periosteum to explore its role in promoting bone regeneration through nerves. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize the electrically active biomimetic periosteum. Here, the in vitro effects exerted by the electrically active periosteum on the transformation of Schwann cells into the repair phenotype, axon initial segment (AIS) and dense core vesicle (DCV) of sensory neurons, and bone marrow mesenchymal stem cells are assessed using SEM, immunofluorescence, RNA-sequencing, and calcium ion probes. The electrically active periosteum stimulates Schwann cells into a neuroprotective phenotype via the Fanconi anemia pathway, enhances the AIS effect of sensory neurons, regulates DCV transport, and releases neurotransmitters, promoting the osteogenic transformation of bone marrow mesenchymal stem cells. Microcomputed tomography and other in vivo techniques are used to study the effects of the electrically active periosteum on bone regeneration. The results show that the electrically active periosteum promotes nerve-induced osteogenic repair, providing a potential clinical strategy for bone regeneration.

Photosensitive and Conductive Hydrogel Induced Innerved Bone Regeneration for Infected Bone Defect Repair.

Repairing infected bone defects is a challenge in the field of orthopedics because of the limited self-healing capacity of bone tissue and the susceptibility of refractory materials to bacterial activity. Innervation is the initiating factor for bone regeneration and plays a key regulatory role in subsequent vascularization, ossification, and mineralization processes. Infection leads to necrosis of local nerve fibers, impeding the repair of infected bone defects. Herein, a biomaterial that can induce skeletal-associated neural network reconstruction and bone regeneration with high antibacterial activity is proposed for the treatment of infected bone defects. A photosensitive conductive hydrogel is prepared by incorporating magnesium-modified black phosphorus (BP@Mg) into gelatin methacrylate (GelMA). The near-infrared irradiation-based photothermal and photodynamic treatment of black phosphorus endows it with strong antibacterial activity, improving the inflammatory microenvironment and reducing bacteria-induced bone tissue damage. The conductive nanosheets and bioactive ions released from BP@Mg synergistically improve the migration and secretion of Schwann cells, promote neurite outgrowth, and facilitate innerved bone regeneration. In an infected skull defect model, the GelMA-BP@Mg hydrogel shows efficient antibacterial activity and promotes bone and CGRP+ nerve fiber regeneration. The phototherapy conductive hydrogel provides a novel strategy based on skeletal-associated innervation for infected bone defect repair.

Both-Column Acetabular Fractures: Should Pelvic Ring Reduction or Acetabulum be Performed First?

OBJECTIVE: Both-column acetabular fracture is a type that accumulates both the pelvis and acetabulum with complex fracture line alignment and has variant fracture fragments. The selection of different reduction landmarks and sequences produces different qualities of reduction. This study aims to compare the operation-related items, quality of reduction, and hip functional outcome by using different reduction landmarks and sequences for management of both-column acetabular fractures (BCAF). METHODS: A consecutive cohort of 42 patients from January 2013 to January 2019 with BCAF were treated operatively with different reduction landmarks and sequences: pelvic ring fractures reduction first (PRFRF group) and acetabular fractures reduction first (AFRF group). Preoperative computer visual surgical procedures were applied. There were 22 patients in PRFRF group and 20 patients in AFRF group. The surgical details, complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. The functional outcome was evaluated by the modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data. RESULTS: The real reduction sequence in both groups was almost identical to the preoperative surgical procedures. The excellent/good quality of reduction in PRFRF group (21/22) was better than AFRF group (17/20). Operative time (152.3 ± 16.3 mins) and intra-operative blood loss (639.5 ± 109.9ml) were significantly reduced in PRFRF group (p < 0.05). The incidence of deep vein thrombosis in PRFRF group (2/22) was less than AFRF group (4/20), but without statistical signification. CONCLUSION: Selection of an appropriate reduction landmark and sequence could result in better quality of reduction, operative time, and decreased blood loss during treatment of BCAF.

Small Intestinal Submucosa Biomimetic Periosteum Promotes Bone Regeneration.

BACKGROUND: Critical bone defects are a significant problem in clinics. The periosteum plays a vital role in bone regeneration. A tissue-engineered periosteum (TEP) has received increasing attention as a novel strategy for bone defect repairs. METHODS: In this experiment, a biomimetic periosteum was fabricated by using coaxial electrospinning technology with decellularized porcine small intestinal submucosa (SIS) as the shell and polycaprolactone (PCL) as the core. In vitro, the effects of the biomimetic periosteum on Schwann cells, vascular endothelial cells, and bone marrow mesenchymal stem cells were detected by a scratch test, an EdU, a tube-forming test, and an osteogenesis test. In vivo, we used HE staining to evaluate the effect of the biomimetic periosteum on bone regeneration. RESULTS: In vitro experiments showed that the biomimetic periosteum could significantly promote the formation of angiogenesis, osteogenesis, and repaired Schwann cells (SCs). In vivo experiments showed that the biomimetic periosteum could promote the repair of bone defects. CONCLUSIONS: The biomimetic periosteum could simulate the structural function of the periosteum and promote bone repair. This strategy may provide a promising method for the clinical treatment of skull bone defects.

The novel infra-pectineal buttress plates used for internal fixation of elderly quadrilateral surface involved acetabular fractures.

OBJECTIVES: In geriatric acetabular fractures, the quadrilateral surface (QLS) was frequently involved in acetabular fracture patterns and accompanied by medial displacement. It was important to buttress the medial displaced QLS and reconstruct the congruity of the affected acetabulum. To evaluate the clinical effectiveness of the novel infra-pectineal quadrilateral surface buttress plates for the treatment of geriatric acetabular fractures. METHODS: Twenty-three geriatric patients who were treated for acetabular fractures involving QLS with the novel infra-pectineal buttress plates (NIBP) through a single supra-ilioinguinal approach between January 2015 and June 2019 were retrospectively analyzed; all patients received at least 1 year's follow-up. All patients were aged ≥60 years old and including 18 males and five females. Radiologic and clinical outcomes of patients involved in the study were collated and analyzed according to the Matta scoring system and the Merle D'Aubigné-Postel scoring system. The functional recovery scoring was compared using q-test. RESULTS: All 23 consecutive patients had relatively satisfactory clinical treatment effectiveness. Average ages, length of incision, operation time, and intraoperative blood loss were 69.8 ± 6.1 years, 12.1 ± 2.6 cm, 166.5 ± 43.5 min, and 500 (500,700) ml, respectively. According to the Matta scoring system, 14 cases of reduction were graded as excellent, five as good, and four as fair. At the last follow-up, the clinical outcome evaluation was excellent in 13 cases, good in seven cases, and poor in three cases with the use of the Merle D'Aubigné-Postel scoring system. The difference of modified Merle D'Aubigne-Postel score at 3 months, 6 months and last follow up was statistically significant (F = 21.56, p < 0.05). Postoperative lateral femoral cutaneous nerve injury occurred in three patients and heterotopic ossification occurred in one patient. CONCLUSIONS: For the treatment of geriatric acetabular fractures, the NIBP could provide stable and effective fixation to the QLS involved acetabular fractures, and related satisfactory clinical results with few complications were noted.

Assessment of acute traumatic cervical spinal cord injury using conventional magnetic resonance imaging in combination with diffusion tensor imaging-tractography: a retrospective comparative study.

PURPOSE: The application of conventional magnetic resonance imaging (MRI) in combination with diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) to diagnose acute traumatic cervical SCI has not been studied. This study explores the role of MRI with DTI-DTT in the diagnosis of acute traumatic cervical spinal cord injury (SCI). METHODS: Thirty patients with acute traumatic cervical SCI underwent conventional MRI and DTI-DTT. Conventional MRI was used to detect the intramedullary lesion length (IMLL) and intramedullary hemorrhage length (IMHL). DTI was used to detect the spinal cord's fractional anisotropy (FA) and apparent diffusion coefficient value, and DTT detected the imaginary white matter fiber volume and the connection rates of fiber tractography (CRFT). Patients' neurological outcome was determined using the American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades. RESULTS: Patients were divided into group A (without AIS grade conversion) and group B (with AIS grade conversion). The IMLL and IMHL of group A were significantly higher than those of group B. The FA and CRFT of group A were significantly lower than those of group B. The final AIS grade was negatively correlated with the IMLL and IMHL, and positively correlated with the FA and CRFT. According to imaging features based on conventional MRI and DTI-DTT, we propose a novel classification and diagnostic procedure. CONCLUSIONS: The combination of conventional MRI with DTI-DTT is a valid diagnostic approach for SCI. Lower IMLL and IMHL, and higher FA value and CRFT are linked to better neurological outcomes.

Acute hyperextension myelopathy in children: Radiographic predictors of clinical improvement.

STUDY DESIGN: Retrospective case series SETTING: Three hospitals in China. OBJECTIVE: Previous research indicates that only neurological status on admission determines prognosis of acute hyperextension myelopathy (AHM). The object of this study is to analyze other unfavorable predictors of AHM in children. METHODS: The clinical data of children with AHM were retrospectively analyzed. The ASIA impairment scale (AIS) grade was recorded upon admission and at last follow-up. Intramedullary lesion length (IMLL) was measured in the sagittal T2-weighted imaging (T2WI) within two weeks after onset; gadolinium enhancement in the cord was recorded for each patient. Relationships among AIS grade, IMLL, gadolinium enhancement in the cord, and clinical improvement were assessed. RESULTS: A total of 33 patients were included in this retrospective study. IMLL between complete and incomplete injury was significantly different (p < 0.01) in the subacute stage, and no difference was observed in the acute stage. Correlation analysis revealed that AIS grade on admission (r = 0.906, p < 0.001) was significantly positively correlated with clinical improvement. IMLL (r = -0.608, p < 0.001) and abnormal gadolinium enhancement (r = -0.816, p < 0.001) in the cord in the subacute stage were significantly negatively correlated with clinical improvement. There were no associations between IMLL in the acute stage and clinical improvement (r = -0.248, p = 0.242). The statistically significant predictors of clinical improvement were AIS grade on admission, IMLL in the subacute stage, and abnormal gadolinium enhancement. CONCLUSION: IMLL in the subacute stage and abnormal gadolinium enhancement in the cord are two other prognostic predictors of AHM in children.

Finite element analysis of the Union Plate in treating elderly acetabular fracture patients.

BACKGROUND: Elderly acetabular fractures are one of the more difficult types of fractures to resolve. For patients at this age, the more common type of fracture is comminuted. How to better fix this type of fracture has always been an issue of concern. This study was performed to observe the mechanical properties of different internal fixation methods used in treating elderly acetabular fracture patients. METHODS: A model of a comminuted acetabular fracture in osteoporosis was established, consisting of an anterior column-posterior hemitransverse fracture with disruption of the quadrilateral surface. Fixation of the acetabular fracture model using a reconstruction plate and Union Plates was simulated. For the different internal fixation methods, static and transient modal analyses were performed under different loads, with an action time of 0.21 s and an analysis time of 0.7 s. The stress of the model was observed in the static analysis, and the displacement of the nodes and the entire model in the U1 direction was observed in the transient modal analysis. RESULTS: In the static analysis, the stress of the osteoporosis model, the suprapectineal pelvic reconstruction plate model, the infrapectineal quadrilateral surface buttress plate model, and the suprapectineal quadrilateral surface buttress plate model were 42.62 MPa, 37.49 MPa, 44.39 MPa, and 46.15 MPa, respectively. The stress was mainly distributed near the suprapubic branch. The corresponding displacement in the U1 direction was 0.1500 mm, 0.1020 mm, 0.0836 mm, and 0.0990 mm, respectively. In the transient modal analysis, there was a significant difference in displacement between the different models (P < 0.05). When different loads were applied with the same fixation method, there was no significant difference in model displacement (P > 0.05). CONCLUSION: Static and transient modal analyses show that the infrapectineal quadrilateral surface buttress plate or the suprapectineal quadrilateral surface buttress plate has an advantage in maintaining the stability of fracture fragments when fixing comminuted acetabular fractures in elderly individuals. The infrapectineal quadrilateral surface buttress plate also presents better biomechanical results.

Treatment of Upper Cervical Spinal Cord Injury (Unstable C1-C2) by Direct Visualization and Nailing Technique and the Advantages of Early MRI.

Background: The treatment of C1-C2 fractures mainly depends on fracture type and the stability of the atlantoaxial joint. Disruption of the C1-C2 combination is a big challenge, especially in avoiding vertebral artery, nerve, and vein sinus injury during the operation. Purpose: This study aims to show the benefit of using the posterior approach and pedicle screw insertion by nailing technique and direct visualization to treat unstable C1-C2 and, moreover, to determine the advantages of performing early MRI in patients with limited neck movement after trauma. Method: Between Jan 2017-Feb 2019, we present 21 trauma patients who suffered from C1, C2, or unstable atlantoaxial joint. X-ray, computed tomography (CT), and magnetic resonance image (MRI) were performed preoperatively. All the patients underwent our surgical procedure (posterior approach and pedicle screw placement by direct visualization and nailing technique). Result: The mean age was 41.1 years old, 8 females and 14 males. The average follow-up time was 2.6 years. Four patients were with C1 fracture, seven with C2 fracture, six with atlantoaxial dislocation, and four with C1 and C2 fractures. The time of MRI was between 12 hours and 48 hours; neck movement symptoms appeared between 2 days and 2 weeks. Conclusion: The posterior approach to treat the C1 and C2 fractures or dislocation by direct visualization and nailing technique can reduce the risk of the vertebral artery, vein sinus, and nerve root injuries with significant improvement. It can show a better angle view while inserting the pedicle screws. An early MRI (12-48 hours) is essential even if no symptoms appear at the time of admission, and if it is normal, it is necessary to repeat it. The presence of skull bleeding can be associated with upper neck instability.

Medical Communication Services after Traumatic Spinal Cord Injury.

It is difficult to assess and monitor the spinal cord injury (SCI) because of its pathophysiology after injury, with different degrees of prognosis and various treatment methods, including laminectomy, durotomy, and myelotomy. Medical communication services with different factors such as time of surgical intervention, procedure choice, spinal cord perfusion pressure (SCPP), and intraspinal pressure (ISP) contribute a significant role in improving neurological outcomes. This review aims to show the benefits of communication services and factors such as ISP, SCPP, and surgical intervention time in order to achieve positive long-term outcomes after an appropriate treatment method in SCI patients. The SCPP was found between 90 and 100 mmHg for the best outcome, MAP was found between 110 and 130 mmHg, and mean ISP is ≤20 mmHg after injury. Laminectomy alone cannot reduce the pressure between the dura and swollen cord. Durotomy and duroplasty considered as treatment choices after severe traumatic spinal cord injury (TSCI).

Controlled delivery of bone morphogenic protein-2-related peptide from mineralised extracellular matrix-based scaffold induces bone regeneration.

Ideal bone tissue engineering scaffolds composed of extracellular matrix (ECM) require excellent osteoconductive ability to imitate the bone environment. We developed a mineralised tissue-derived ECM-modified true bone ceramic (TBC) scaffold for the delivery of aspartic acid-modified bone morphogenic protein-2 (BMP-2) peptide (P28) and assessed its osteogenic capacity. Decellularized ECM from porcine small intestinal submucosa (SIS) was coated onto the surface of TBC, followed by mineralisation modification (mSIS/TBC). P28 was subsequently immobilised onto the scaffolds in the absence of a crosslinker. The alkaline phosphatase activity and other osteogenic differentiation marker results showed that osteogenesis of the P28/mSIS/TBC scaffolds was significantly greater than that of the TBC and mSIS/TBC groups. In addition, to examine the osteoconductive capability of this system in vivo, we established a rat calvarial bone defect model and evaluated the new bone area and new blood vessel density. Histological observation showed that P28/mSIS/TBC exhibited favourable bone regeneration efficacy. This study proposes the use of mSIS/TBC loaded with P28 as a promising osteogenic scaffold for bone tissue engineering applications.

Internal fixation of anterior acetabular fractures with a limited pararectus approach and the anatomical plates: preliminary results.

BACKGROUND: The surgical treatment of acetabular fracture has adverse outcomes and high risk, and minimally invasive method is a good way to reduce complications and improve hip joint function. This study is to investigate the treatment of certain acetabular fractures primarily involving the anterior column and quadrilateral plate using a limited pararectus approach and the anatomical plates. METHODS: A consecutive cohort of 17 patients with anterior displaced acetabular fractures were managed operatively with a limited approach and the anatomical plates. Ten patients had anterior column fractures, 1 patient had anterior wall fracture, 4 patients had transverse fractures and 2 patients had anterior column with posterior hemi-transverse fractures. The inferior half of the pararectus approach was adopted to open the medial window and to access the anterior column and the quadrilateral plate. The anatomical plates were used for internal fixation. Residual displacements were assessed on the postoperative CT scans using a standardized digital method. The surgical details, hip functional outcomes, and complications were noted. RESULTS: All of the patients were operated using the limited pararectus approach and the anatomical plates successfully. The mean operative time and blood loss were 90.9 min and 334.1 ml, respectively. The average postoperative residual gap and step displacement on CT were 2.9 mm and 0.7 mm, respectively. The radiological outcome was estimated according to the Matta score, ten of the cases were graded anatomical, six were graded imperfect, and one was graded poor. Follow up averaged 15 months. Functional outcomes were excellent for nine, good for six, and fair for two. It was noted that one case of peritoneal injury was repaired intraoperatively. CONCLUSIONS: The limited pararectus approach with the advantages of less trauma, direct exposure to the anterior column and quadrilateral plate. The anatomical plates can fit with the surface of the acetabulum, which saves the time of remodeling plates during operation and facilitate fracture reduction. The combination approach can be a good choice for limited surgery of displaced anterior acetabular fractures especially involving the quadrilateral plate.