Conventional Fixation Methods Research Articles

In situ Scleral Suture Fixation of an Injector-delivered Intraocular Lens

Purpose: We evaluated a novel surgical technique for managing the intraocular lens (IOL) through in situ scleral fixation and its outcomes.Case summary: This retrospective case series included three eyes of three patients treated with the in situ scleral fixation technique for IOL. Our method involves suturing the haptics of an already intraocularly injected IOL in situ using a Siepser sliding knot suture, while the other haptic is tied externally. Notably, no intraoperative or postoperative complications, such as cystoid macula edema, were observed.Conclusions: This novel technique is a user-friendly and effective approach to improve IOL-capsular bag stability, requiring minimal intraocular intervention or preoperative preparation compared to conventional IOL scleral fixation methods. Furthermore, it is particularly effective for addressing concerns related to IOL-capsular bag stability following IOL insertion, as it eliminates the possibility of performing the typical IOL scleral fixation due to the absence of preoperative preparation and evaluation.

Fixation method of a single muscle fiber by magnetic force for stretching, transportation, and evaluation of mechanical properties

Engineered muscle fibers are attracting interest in bio-actuator research as they can contribute to the fabrication of actuators with a high power/size ratio for micro-robots. These fibers require to be stretched during culture for functional regulation as actuators and require a fixation on a rigid substrate for stretching in culture and evaluation of mechanical properties, such as Young’s modulus and contraction force. However, the conventional fixation methods for muscle fibers have many restrictions as they are not repeatable and the connection between fixation part and the muscle fibers detaches during culture; therefore, the fixation becomes weak during culture, and direct measurement of the muscle fibers’ mechanical properties by a force sensor is difficult. Therefore, we propose a facile and repeatable fixation method for muscle fibers by mixing magnetite nanoparticles at both ends of the muscle fibers to fabricate magnetic ends. The fiber can be easily attached and detached repeatedly by manipulating a magnet that applies a magnetic force larger than 3 mN to the magnetic ends. Thus, the muscle fiber can be stretched fiber during culture for functional regulation, transported between the culture dish and measurement system, and directly connected to the force sensor for measurement with magnetic ends. The muscle fiber connected with magnetic ends have a long lifetime (∼4 weeks) and the cells inside had the morphology of a skeletal muscle. Moreover, the muscle fiber showed a contraction (specific force of 1.02 mN mm−2) synchronized with electrical stimulation, confirming the muscle fiber fabricated and cultured using our method had similar morphology and function as bio-actuators in previous research. This research demonstrates the advantages of the fixation method using muscle fibers with magnetic ends; the fibers are stretched during culture, and the transportation and force measurement of weak and tiny muscle fibers could be finished in 1 min.

Panfacial fractures management, a report of surgical treatment sequence in three cases: A case series study

Multiple facial fractures, which involve the upper, middle, and lower thirds of the face, are called Panfacial fractures, and their management is one of the biggest challenges in the field of maxillofacial surgery. The proximity of maxillofacial skeleton to important sensory or vital structures such as the visual, olfactory, masticatory and respiratory systems and intracranial components in addition to negative effects on esthetic aspects of the face have doubled the intricacy. Small or thin fractured segments that are difficult to find and stabilize make management of pan facial fractures different from anywhere else in the body.
 One major challenge is to find the best pattern and sequence of treatment. There are different concepts, depending on the surgeon's experience and the pattern of fracture. This study reports three patients with the diagnosis of pan facial fractures. A 54-year-old woman, an 18-year-old and a 14-year-old man that were all victims of road traffic injuries (MVA). Conventional open reduction and internal fixation methods have been used and favorable results have been obtained in follow-up periods.

Shear Strength Behaviors of Aeolian Sand Solidified by Microbially Induced Calcite Precipitation and Basalt Fiber Reinforcement.

Aeolian sand flow is identified as the main factor in the formation of sandstorms. However, conventional sand fixation methods cannot meet the current development requirements of environmental protection. In this paper, the method using Microbially Induced Calcite Precipitation (MICP) combined with basalt fiber reinforcement (BFR) was adopted to solidify the aeolian sand. Consolidated undrained triaxial shear tests were carried out to analyze the influence of fiber content, fiber length, confining pressure, and other factors on stress-strain characteristics, peak strength, brittleness index, and shear strength of aeolian sand. A shear strength model of aeolian sand solidification using MICP-BFR and considering the effect of fiber length and fiber content is established according to the test results. The results show that the peak strength of aeolian sand solidified by MICP-BFR is remarkably higher than that of aeolian sand solidified by MICP alone, and the peak strength rises with the increasing fiber length, fiber content, and confining pressure. The application of fiber can effectively reduce the brittleness index of aeolian sand solidified by MICP and improve the sample ductility. As fiber content and fiber length increase, the cohesion of solidified aeolian sand increases while the internal friction angle changes relatively little. In the limited range set by the test, the fiber length of 12 mm and the fiber content of 1.0% constitute the optimum reinforcement condition. The test results coincide with the model prediction results, indicating that the new model is fitting for predicting the shear strength of aeolian sand solidified by MICP-BFR. The research results provide an important reference value for guiding the practice of wind prevention and sand fixation in desert areas.

The study of biomechanics and finite element analysis on a novel plate for tibial plateau fractures via anterolateral supra-fibular-head approach

For Schatzker type II split-depressed tibial plateau fractures involving the fractures of anterolateral and posterolateral columns (APC), the optimal fixation scheme is controversial. The objectives of this study were: (1) to introduce a newly designed plate for treating APC fractures via biomechanical tests and finite element analysis (FEA), and (2) to compare it with two conventional fixation methods. APC fracture models were created and randomly assigned to three groups (Groups A-C). Group A was fixed with a 3.5-mm lateral locking plate, Group B was fixed with a 3.5-mm lateral locking plate and two 3.5-mm cannulated screws (hybrid fixation). Group C was fixed with the newly designed plate. It is an arched locking plate for fixing the lateral tibial plateau via the anterolateral supra-fibular-head approach. Each fracture model experienced a gradually increasing axial compressive load ranging from 250 to 750 N using a customized indenter. Biomechanical analysis demonstrated that the newly designed plate showed the minimum displacement among the three methods, followed by the hybrid fixation method. Conversely, the 3.5-mm lateral locking plate displayed the maximum displacement in APC fractures (p < 0.05). FEA results indicated that at 750 N, the maximum displacements for Groups A-C were measured as 3.06 mm, 2.74 mm, and 2.08 mm, respectively. Moreover, the maximum stresses recorded for the implant in Groups A-C at 750 N were 208.32 MPa, 299.59 MPa, and 143.26 MPa, while for the bone, they were 47.12 MPa, 74.36 MPa, and 40.01 MPa. The overall trends at 250 N and 500 N were consistent with those observed at 750 N. In conclusion, due to good biomechanical performance and FEA results, the newly designed plate represents a promising choice for managing APC fractures of the tibial plateau.

Energy Intensified Nitrogen Fixation Through Fast Modulated Gas Discharge from Pyramid-shaped Micro-electrode

Plasma-assisted nitrogen fixation has emerged as a promising alternative to conventional nitrogen fixation methods. In this study, we investigate the feasibility of plasma-assisted nitrogen fixation using an AC-driven dielectric barrier discharge generated from the micro-tips of a specially designed fast-modulated pyramid-shaped electrode. The obtained result is compared with the conventional flat electrode. Our results demonstrate that pyramid-shaped micro-tip electrodes can excite more nitrogen molecules than flat electrodes. Thus, pyramid electrodes have 58% more nitrogen oxides yield efficiency at 32% less energy cost. The highest nitrogen fixation is attained at 60% to 70% of oxygen concentration in nitrogen-feeding gas. These findings suggest that discharge through microtip is a promising and viable technology that could play a significant role in reducing the energy cost of the plasma-assisted nitrogen fixation method to meet the growing demand for sustainable nitrogen-based fertilizers.

A new bone adhesive to fix mandible fractures in New Zealand Rabbits: cytotoxicity assay and comparison of bone formation with conventional plate and screw method

Statement of the Problem: Using plate and screws as the conventional bone fixation method in maxillofacial fractures leads to many complications as plate exposure, infection or unpleasant feeling on touching. Finding a substitute fixation method has been a far desire for many years.&#x0D; Purpose: This study compared the new bone formation using an experimental bone adhesive containing a functional monomer (benzophenone tetracarboxylic di-methacrylate, BTDMA) and the conventional plate and screw in fractured mandibles of rabbit.&#x0D; Materials and Method: This is an experimental animal study. The artificial fractures were induced at the mandibular angles of three male New Zealand rabbits. Screw and plate were used as control and titanium mesh with the resin-based bone adhesive containing 15 wt. % BTDMA monomer were applied as treatment. The mandible radiography were obtained and the density of the fracture line was compared to the control. The newly formed bone was assessed by a microscope.&#x0D; Results: The results obtained from the MTT cytotoxicity assay showed that 70% of cells were able to grow in the presence of the adhesive. The radiographic density of mesh-adhesive specimens was 119.88±76.29, while conventional plate specimens' density was 120.38±73.89. The average new bone formation score in the mesh specimens and plate specimens was 3.67±4.62 and 7±4.36, respectively. There was no significant difference between the two groups. The application of bone adhesive containing 15% BTDMA monomer in a group of the rabbits showed lamellar bone formation.&#x0D; Conclusion: Using bone adhesives containing BTDMA could lead to a new bone formation with high density in the case of adequate bonding to the fractured area.

The Profile of microRNA Expression in Diffuse Large B-Cell Lymphoma

Non-Hodgkin’s lymphoma (NHL) is a heterogeneous group of cancers characterized by different pathogenesis and prognosis. The main methods for treating NHL are chemotherapy, immunochemotherapy, and radiation therapy; however, most of these cancers are known to be chemoresistant or return rapidly after the short chemotherapy-induced remission. Therefore, searching for alternative cytoreductive therapy options is quite relevant today. Aberrant microRNA (miRNA) expression is one of the mechanisms responsible for the emergence and progression of lymphoid malignancies. This study was aimed at identifying the miRNA expression profile in diagnostic biopsy specimens harvested from the lymph nodes affected by diffuse large B-cell lymphoma (DLBCL) and identifying miRNA markers, which can potentially be used to design a novel type of ta-rgeted anticancer drugs that would allow one to achieve maximum therapy personalization and increase its efficacy. The key study objects were histological specimens harvested from the lymph nodes by excisional d-iagnostic biopsy and treated using the conventional histomorphological formalin fixation methods. The study group consisted of patients with DLBCL (n = 52). The biopsy specimens harvested from patients with reactive lymphadenopathy (RL) (n = 40) constituted the control group. The miR-150 expression level was reduced over 12-fold (p = 3.6 × 10‒15) compared to that in the tissues of non-cancerous nodular masses. B-ioinformatic analysis revealed that miR-150 is involved in regulation of hematopoiesis and lymphopoiesis. The findings obtained in this study allow considering miR-150 a promising therapeutic target having a great potential for clinical applications.

Formalin-free fixation and xylene-free tissue processing preserves cell-hydrogel interactions for histological evaluation of 3D calcium alginate tissue engineered constructs

Histological evaluation of tissue-engineered products, including hydrogels for cellular encapsulation, is a critical and invaluable tool for assessing the product across multiple stages of its lifecycle from manufacture to implantation. However, many tissue-engineered products are comprised of polymers and hydrogels which are not optimized for use with conventional methods of tissue fixation and histological processing. Routine histology utilizes a combination of chemical fixatives, such as formaldehyde, and solvents such as xylene which have been optimized for use with native biological tissues due to their high protein and lipid content. Previous work has highlighted the challenges associated with processing hydrogels for routine histology due to their high water content and lack of diverse chemical moieties amenable for tissue fixation with traditional fixatives. Thus, hydrogel-based tissue engineering products are prone to histological artifacts during their validation which can lead to challenges in correctly interpreting results. In addition, chemicals used in conventional histological approaches are associated with significant health and environmental concerns due to their toxicity and there is thus an urgent need to identify suitable replacements. Here we use a multifactorial design of experiments approach to identify processing parameters capable of preserving cell-biomaterial interactions in a prototypical hydrogel system: ionically crosslinked calcium alginate. We identify a formalin free fixative which better retains cell-biomaterial interactions and calcium alginate hydrogel integrity as compared to the state-of-the-art formalin-based approaches. In addition, we demonstrate that this approach is compatible with a diversity of manufacturing techniques used to fabricate calcium alginate-based scaffolds for tissue engineering and cell therapy, including histological evaluation of cellular encapsulation in 3D tubes and thin tissue engineering scaffolds (∼50 μm). Furthermore, we show that formalin-free fixation can be used to retain cell-biomaterial interactions and hydrogel architecture in hybrid alginate-gelatin based scaffolds for use with histology and scanning electron microscopy. Taken together, these findings are a significant step forward towards improving histological evaluation of ionically crosslinked calcium alginate hydrogels and help make their validation less toxic, thus more environmentally friendly and sustainable.

Single-Stage Externalized Locked Plating for Treatment of Unstable Meta-Diaphyseal Tibial Fractures

(1) Background: Unstable meta-diaphyseal tibial fractures represent a heterogeneous group of injuries. Recently, good clinical results have been reported when applying a technique of externalized locked plating in appropriate cases, highlighting its advantage in terms of less additional tissue injury compared with conventional methods of fracture fixation. The aims of this prospective clinical cohort study were, firstly, to investigate the biomechanical and clinical feasibility and, secondly, to evaluate the clinical and functional outcomes of single-stage externalized locked plating for treatment of unstable, proximal (intra- and extra-articular) and distal (extra-articular), meta-diaphyseal tibial fractures. (2) Methods: Patients, who matched the inclusion criteria of sustaining a high-energy unstable meta-diaphyseal tibial fracture, were identified prospectively for single-stage externalized locked plating at a single trauma hospital in the period from April 2013 to December 2022. (3) Results: Eighteen patients were included in the study. Average follow-up was 21.4 ± 12.3 months, with 94% of the fractures healing without complications. The healing time was 21.1 ± 4.6 weeks, being significantly shorter for patients with proximal extra- versus intra-articular meta-diaphyseal tibial fractures, p = 0.04. Good and excellent functional outcomes in terms of HSS and AOFAS scores, and knee and ankle joints range of motion were observed among all patients, with no registered implant breakage, deep infection, and non-union. (4) Conclusions: Single-stage externalized locked plating of unstable meta-diaphyseal tibial fractures provides adequate stability of fixation with promising clinical results and represents an attractive alternative to the conventional methods of external fixation when inclusion criteria and rehabilitation protocol are strictly followed. Further experimental studies and randomized multicentric clinical trials with larger series of patients are necessary to pave the way of its use in clinical practice.

MicroRNA Expression Profiling of Diffuse Large B-Cell Lymphoma

Non-Hodgkin lymphoma (NHL) is a heterogeneous group of cancers that differ in pathogenesis and prognosis. The main methods of treating NHL include chemotherapy, immunochemotherapy, and radiation therapy. However, a significant proportion of these tumors are chemoresistant or rapidly recur after a short chemotherapy-induced remission. In this regard, the search for alternative cytoreductive therapeutic methods is relevant. Aberrant expression of microRNA (miRNA) is one of the mechanisms responsible for the emergence and progression of malignant lymphoid neoplasms. We analyzed the profile of miRNA expression in the biopsy material from lymph nodes affected by diffuse large B-cell lymphoma (DLBCL). The key material of the study was histological preparations of lymph nodes obtained by excisional diagnostic biopsy and treated using conventional histomorphological formalin fixation methods. The study group consisted of patients with DLBCL (n = 52); the control group consisted of patients with reactive lymphadenopathy (RL) (n = 40). It was shown that the miR-150 expression level in DLBCL was reduced by more than 12 times (</>p = 3.6 x 10^(-15)) compared with RL. Bioinformatics analysis revealed the involvement of miR-150 in the regulation of hematopoiesis and lymphopoiesis. The data we obtained allow us to consider miR-150 as a promising therapeutic target with great potential in clinical practice.

Biplane double supported screw fixation in femoral neck fractures using percutaneous approach

Introduction: Fracture neck of femur has always presented a great challenge to the Orthopaedic surgeons. Results depend upon adequacy of reduction and stable fixation. Fixation with cannulated cancellous screws is usually adequate for femoral neck fractures. The aim of the study was to analyze the results of treatment of fracture neck of femur with cannulated cancellous screw fixation using BDSF method.Materials and Methods: This prospective study was carried out in the postgraduate Department of Orthopaedics, Govt. Bone and Joint Hospital, an associated hospital of Govt. Medical College Srinagar from 2019-2021. A total of 25 patients who presented in the department with femoral neck fractures and qualified the inclusion criteria were included in the study.Results: Among 25 patients 12 (48%) patients achieved excellent results, 8 (32%) patients achieved good results, 3 (12%) patients achieved fair results and 2 (8%) patients achieved poor results. 80% of the patients achieved either excellent or good result.Conclusion: BDSF is a novel method of fixation of femoral neck fractures, associated with higher axial fixation strength and union rate compared to conventional fixation methods. It employs bi-plane positioning of three cannulated screws placed at steeper angles to the diaphyseal axis.

High pressure frozen oocytes have improved ultrastructure but reduced cleavage rates compared to conventionally fixed or vitrified oocytes.

Live birth rates are lower for cryopreserved oocytes than for fresh IVF cycles, indicating a need for improved methodologies. The aim of this study was to determine if high pressure freezing (HPF) could improve both ultrastructural preservation and cryopreserved oocyte quality when compared to conventional fixation and vitrification methods. Sheep oocytes and embryos were prepared by HPF or vitrification, with or without cryoprotectants. Frozen oocytes were prepared for transmission electron microscopy or warmed, in vitro fertilised and the recovery and cleavage rates recorded. Blastocyst rates were similar between fresh, HPF and vitrified embryos. HPF oocytes had improved ultrastructure compared to conventional fixation or vitrification, but had poorer survival and cleavage rates compared to vitrified oocytes. Freeze-substitution of cryopreserved oocytes and transmission electron microscopy demonstrated disruption of the oocyte ultrastructure in the presence of cryoprotectants. Superior preservation of ultrastructure was observed in HPF oocytes compared to vitrification or conventional fixation methods. In the presence of CP, both embryos and oocytes could survive HPF and warming but oocytes had reduced development. The HPF method has potential to be developed and lead to improved oocyte and embryo cryopreservation and outcomes for assisted reproduction.

Biomechanical Comparative Study for Osteosynthesis of Pauwels Type III Femoral Neck Fractures: Conventional Devices versus Novel Fixed Angle Devices.

PurposeOsteosynthesis has been recommended for treatment of Pauwels type III femoral neck fractures in young patients. However, no implant of choice has been reported so far. This study was conducted in order to compare the fixation stability of two conventional fixation methods with three different novel fixed angle devices in this type of fracture.Materials and MethodsA total of 25 composite femurs (4th Generation Saw bone; Pacific Research Laboratories, USA) corresponding to human bone were used. Pauwels type III fracture type was uniformly reproduced. Specimens were fixed with a cannulated screw, cannulated screw with cable, and Intertan nail, dynamic hip screw, and IKEY nail. Measurement of failure loads and the rotational change of the femoral head fragment was performed for evaluation of fixation stability.ResultsAll implants were compared with cannulated screw and dynmaic hip screw. No meaningful improvement was observed for the cannulated screw with cable compared with the cannulated screw and dynamic hip screw. Meaningful improvement in load-to-failure and y-rotation and z-rotation was observed for both the Intertan nail and IKEY nail compared with the cannulated screw. However, compared with the dynamic hip screw, only the IKEY nail showed improvement in the same profile but the Intertan nail did not.ConclusionAmong novel fixed angle devices, meaningful improvement was observed for the IKEY nail compared with conventional implants. Strengths of this implant include biomechanical stability and simplicity of surgical technique, indicating that it may be another good option for osteosynthesis of Pauwels type III femoral neck fractures.

P–015 Characterization of ultrastructural morphology of human sperms by field-emission scanning electron microscopy using the NanoSuit method

Abstract Study question Can the NanoSuit method to observe sperm cells in wet conditions help treat male infertility using a field emission scanning electron microscope (FE-SEM)? Summary answer Compared with the conventional fixation method, the NanoSuit method can easily prepare FE-SEM samples without causing contraction and denaturation of human sperm cells. What is known already Evaluation of sperm morphology by optical microscopy is important for identifying male infertility. FE-SEM observation is useful for a more detailed evaluation of sperm morphology; however, a lot of the morphological information of the cells is lost by chemical fixation, dehydration, and freeze-drying. The NanoSuit method enables FE-SEM observation of unfixed cells under a high vacuum environment by electron beam polymerization of extracellular substances called NanoSuit. It has been reported that a sample prepared by the NanoSuit method retains the morphological information of live cells better than a sample prepared by the conventional fixation method. Study design, size, duration This laboratory study was conducted with informed consent and IRB approval. Semen parameters were within the WHO normal reference range. Participants/materials, setting, methods The conventional fixation method sample was prepared by fixing (glutaraldehyde and osmium), dehydration (ethanol and t-butyl alcohol), and freeze-drying. The NanoSuit method sample was introduced into the FE-SEM directly without conducting the above treatments. For observation, a JSM–7100F (JEOL, Japan) was used at an acceleration voltage of 1.0 kV. The vacuum level of the observation chamber was 10–3 to 10–6 Pa. Main results and the role of chance Sperm head segmentation (acrosome, equatorial segment, and post acrosome), midpiece, and tail including endpiece could be clearly identified in the FE-SEM sample prepared by the NanoSuit method. Transmission electron microscopy revealed the existence of a thin polymerized extra layer, the NanoSuit, on the surface of the sperm. It is suggested that the presence of the NanoSuit layer enables FE-SEM observation of the unfixed sperm. The conventional fixation method causes a statistically significant contraction in the sperm head size compared to that calculated from optical micrographs (13.5 μm2 vs. 11.6 μm2, p &amp;lt; 0.001). Furthermore, wheat germ agglutinin (WGA), a lectin, which is known to have the ability to bind to the sperm surface, did not bind to the fixed FE-SEM samples. This means that the original cell surface properties are lost in the fixed sperm sample. On the other hand, the FE-SEM sample prepared by the NanoSuit method did not show a statistically significant contraction of the sperm head compared to that calculated from optical micrographs (13.2 μm2 vs 12.9 μm2, p = 0.416); it also revealed a detailed binding pattern of gold-labelled WGA to the sperm surface. These results indicate that the NanoSuit method can prepare FE-SEM samples without sperm contraction and denaturation. Limitations, reasons for caution Characteristic sperm morphology in patients with male infertility should be investigated in future studies. Wider implications of the findings: The NanoSuit method does not use chemical carcinogens and can prepare an FE-SEM sample in a shorter time than the conventional fixation method. The evaluation of ultrastructural morphology of unfixed sperms by this method may be useful for the identification of new morphological features and the evaluation of male infertility. Trial registration number Not applicable

Comparison between headless compression screws and tension band wires for the fixation of medial malleolar fractures: a prospective randomized trial.

To date, there has been no prospective randomized trial supporting the rationale of the use of headless compression screw (HCS) compared to conventional fixation methods for medial malleolar fractures. This study aimed to prospectively compare the outcomes of the HCS and tension band wire (TBW) for the fixation of medial malleolar fractures. Sixty patients were randomized to receive either an HCS or a TBW for the fixation of a medial malleolar fracture. Clinical outcomes were assessed using the Olerud-Molander ankle score (OMAS), EuroQoL five-dimensional instrument (EQ-5D) score, visual analog scale (VAS) score, patient satisfaction with implant-related symptoms, operative time, and incision length. Radiographic outcomes were assessed using the presence of nonunion, delayed union, and articular incongruity. Clinical and radiographic assessments were performed at 2 and 6weeks and 3, 6, and 12months postoperatively. The OMAS, EQ-5D score, VAS score, and operative time did not differ between the HCS and TBW groups; however, the HCS group had greater satisfaction with implant-related symptoms and smaller incision than the TBW group. There was no difference in the presence of nonunion, delayed union, and articular incongruity. HCS fixation for medial malleolar fractures is not inferior to TBW fixation, while reducing implant-related symptoms. These findings suggest that HCS is a viable alternative for the fixation of medial malleolar fractures.

Peri- and postoperative complications in Le Fort I osteotomies

This retrospective study was performed to report the peri- and postoperative complications encountered by patients who underwent Le Fort I osteotomy, as well as predictor variables affecting the risk of complications.Patients who underwent only Le Fort I osteotomy were included in the study. Information on peri- and postoperative complications were collected from the patient data records. The effects of certain predictor variables on complication rates were also studied.Twenty-four per cent of the patients suffered from complications, six (6.1%) of whom were reoperated. Most of the complications were minor and transient. Compared with one-piece osteotomy, segmental osteotomy was a significant risk factor predisposing patients to postoperative complications (p = 0.04619). Additionally, the use of patient-specific implants seemed to increase the risk of both perioperative and postoperative complications (p = 0.0248).Currently, the conventional plate fixation method is the primary method in Le Fort I osteotomies. Careful patient selection, surgical planning, and selection of surgical technique seem to be the most important factors in reducing the complication risk. Special attention should be paid with segmental osteotomy surgery.

A Workflow for Determining and Sizing Oligomeric Biomolecular Structures with Cryo Single Molecule Localization Microscopy

Single molecule localization microscopy (SMLM) has enormous potential for resolving subcellular structures at the nanometer scale. In order to record localization microscopy data, sample fixation is inevitable to prevent molecular motion during long recording times of minutes up to hours. Crucially, preservation of the sample's ultrastructure during fixation becomes a limiting factor when using conventional fixation methods based on chemical fixatives. Performing SMLM at cryogenic temperatures promises to resolve this issue, thus allowing for investigation of nanoscale structures in their undistorted native state.

Biomechanical evaluation of type p condylar head osteosynthesis using conventional small-fragment screws reinforced by a patient specific two-component plate

BackgroundThe aim of this study was to evaluate via finite element analysis (FEA) the biomechanical behavior of conventional small-fragment screws reinforced by a patient-specific plate in type p condylar head.MethodsA finite element model of the mandible was created using Mimics 12.1 software. A type p condylar head fracture was simulated in the right condyle, and the left condyle was used as a control. Two patterns of fixation were investigated: conventional two-screw fixation and the same fixation system reinforced with a small, patient-specific plate. Surface models were imported into the software Ansys 5.7for further volume mesh generation.ResultsThe highest stress gradients were observed in the cortical layer of the lateral fragment, located near the screw. The conventional fixation method resulted in equivalent stresses 2 to 10 times greater than the reinforced method. Rigidity of fixation in the reinforced method increased up to 1.25–3 times compared to the conventional two-screw technique.ConclusionThis study’s findings suggest significant benefits in unfavorable biomechanical conditions from reinforcement of the standard two-screw fixation of condylar head fractures with a small, patient-specific plate acting as a washer.

Two Polyurethane Adhesives for PVDF Fixation Show Superior Biocompatibility in a Rat Model

Background The current standard for open and laparoscopic repair of incisional hernia consist of an abdominal wall augmentation by mesh implantation. However, the ideal fixation method of the prothesis material remains under discussion, due to potential complications of conventional fixation methods such as chronic abdominal pain or intestinal obstruction. As the use of adhesive based mesh fixation is an option of growing interest, the aim of this experimental study was to investigate the strength and biocompatibility of two newly developed polyurethane-based adhesives in comparison to a cyanoacrylatic adhesive, which is currently in clinical use. Methods Two experimental polyurethane/urea-based adhesives (Adhesive-A and Adhesive-B) were compared to a conventional cyanoacrylatic adhesive and an untreated control group. Biomechanical testing was carried out using a pull-out test in uniaxial tensile mode, while biocompatibility assessment was performed in a rat model with 40 Sprague-Dawley rats receiving a subcutaneous implanted PVDF mesh fixed by the corresponding adhesive. Histological and immunohistochemical analysis by a Tissue FAXS system examined the tissue integration of the mesh/adhesive combination and characterized the foreign body reaction. Results Biomechanical testing of the mesh/adhesive combinations showed a minimal strength of 15.08 N without a significant difference between the groups. Cellular penetration into the mesh/adhesive interface was significantly improved after application of polyurethane adhesives and Adhesive-A showed a significantly lower migration of CD68 positive cells to the adhesive sites compared to cyanoacrylate after 7 days. Conclusion The developed polyurethane-based adhesives are a promising alternative with sufficient adhesive strength and superior short-term biocompatibility to cyanoacrylate.