Anterior Plate Research Articles

Biomechanical Comparison of Anterior Cervical Plate Fixation Versus Integrated Fixation Cage for Anterior Cervical Discectomy and Fusion.

Cadaveric, biomechanic study. To compare the range of motion profiles of the cervical spine following one-level anterior cervical discectomy and fusion (ACDF) constructs instrumented with either an interbody cage and anterior plate or integrated fixation cage in a cadaveric model. While anterior plates with interbody cages are the most common construct of fixation in ACDF, newer integrated cage-plate devices seek to provide similar stability with a decreased implant profile. However, differences in postoperative cervical range of motion between the 2 constructs remain unclear. Six cadaveric spines were segmented into 2 functional spine units (FSUs): C2-C5 and C6-T2. Each FSU was nondestructively bent in flexion-extension (FE), right-left lateral bending (LB), and right-left axial rotation (AR) at a rate of 0.5°/s under a constant axial load until a limit of 2-Nm was reached to evaluate baseline range of motion (ROM). Matched pairs were then randomly assigned to undergo instrumentation with either the standard anterior cage and plate (CP) or the integrated fixation cage (IF). Following instrumentation, ROM was then remeasured as previously described. For CP fixation, ROM increased by 61.2±31.7% for FE, 36.3±20.4% for LB, and 31.7±19.1% for AR. For IF fixation, ROM increased by 64.2±15.5% for FE, 56.7±39.8% for LB, and 94.5±65.1% for AR. There was no significant difference in motion between each group across FE, LB, and AR. This biomechanical study demonstrated increased motion in both the CP and IF groups relative to the intact, un-instrumented state. However, our model showed no differences in ROM between CP and IF constructs in any direction of motion. These results suggest that either method of instrumentation is a suitable option for ACDF with respect to constructing stiffness at time zero.

Robotic-assisted plate fixation of the anterior acetabulum - clinical description of a new technique

IntroductionWe present a detailed procedure for the robotic-assisted plate osteosynthesis of an anterior acetabular fracture. The purpose of this work was to describe a robotic-assisted minimally invasive technique as a possible method for reducing complications, pain, and hospitalization. Another goal was to present technical recommendations and to assess potential pitfalls and problems of the new surgical approach.MethodsSurgery was performed in an interdisciplinary setting by an experienced orthopedic surgeon and a urologist. The DaVinci System with standard instruments was used. Reduction was achieved through indirect traction of a pin that was introduced into the femoral neck and direct manipulation via the plate. The plate position and fixation were achieved through 7 additional minimally invasive incisions.ResultsThe technique has multiple advantages, such as no detachment of the rectus abdominal muscle, a small skin incision, and minimal blood loss. Furthermore, this approach might lower the incidence of hernia formation, infection, and postoperative pain.DiscussionWe see the presented technique as a demanding yet progressive and innovative surgical method for treating acetabular fractures with indications for anterior plate fixation.Trial registrationThe study was approved by the local institutional review board (Nr. 248/18).

Analyzing results of cervical sagittal parameters in patients operated with polyetheretherketone cages without plate.

This was a retrospective longitudinal observational study. The purpose of this study was to analyze the results of cervical sagittal parameters on preoperative and postoperative lateral radiographs in anterior cervical discectomy and fusion (ACDF). ACDF is believed to change craniocervical parameters and thus cervical curvature using polyetheretherketone (PEEK) or titanium cages with or without self-locking as well as an anterior plate, the latter of which has not been shown to provide better clinical or radiological results. Cervical spondylotic myelopathy (CSM) is a common degenerative pathology that can affect one or more levels and treatment has varied over time trying to maintain sagittal parameters within acceptable values where the ACDF is the main treatment. The study was performed in patients with CSM who underwent anterior cervical discectomy, and their pre- and postoperative radiographs were analyzed using Surgimap software a few days before and 3 months after surgery. Fifteen files were included in the study. Statistically significant sagittal balance variables were observed in cervical lordosis (CL) with an increase of 4.73° (P = 0.019) and T1 slope (T1S)-CL with a decrease of -5.93° (P = 0.007). CL and T1S-CL showed favorably modified values when performing ACDF using stand-alone PEEK cages without the need for self-blocking or an anterior plate.

A systematic review of risk factors and adverse outcomes associated with anterior cervical discectomy and fusion surgery over the past decade.

Anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed cervical surgeries in the world, yet there have been several reported complications. To determine the actual incidence of complications related to ACDF as well as any risk variables that may have been identified in earlier research. To evaluate the origin, presentation, natural history, and management of the risks and the complications, we conducted a thorough assessment of the pertinent literature. An evaluation of clinical trials and case studies of patients who experienced one or more complications following ACDF surgery was done using a PubMed, Cochrane Library, and Google Scholar search. Studies involving adult human subjects that were written in the English language and published between 2012 and 2022 were included in the search. The search yielded 79 studies meeting our criteria. The overall rates of complications were as follows: Dysphagia 7.9%, psudarthrosis 5.8%, adjacent segment disease (ASD) 8.8%, esophageal perforations (EPs) 0.5%, graft or hardware failure 2.2%, infection 0.3%, recurrent laryngeal nerve palsy 1.7%, cerebrospinal fluid leak 0.8%, Horner syndrome 0.5%, hematoma 0.8%, and C5 palsy 1.9%. Results showed that dysphagia was a common postoperative sequelae with bone morphogenetic protein use and a higher number of surgical levels being the major risk factors. Pseudarthrosis rates varied depending on the factors such as asymptomatic radiographic graft sinking, neck pain, or radiculopathy necessitating revision surgery. The incidence of ASD indicated no data to support anterior cervical plating as more effective than standalone ACDF. EP was rare but frequently fatal, with no correlation found between patient age, sex, body mass index, operation time, or number of levels.

Wrist & Hand

The April 2024 Wrist & Hand Roundup360 looks at: Lunocapitate versus four-corner fusion in scapholunate or scaphoid nonunion advanced collapse: a randomized controlled trial; Postoperative scaphoid alignment, smoking, and avascular necrosis determine outcomes; Grip strength signals broader health concerns in females with distal radius fractures; Clearing the smoke: how smoking status influences recovery from open carpal tunnel release surgery; Age matters: assessing the likelihood of corrective surgery after distal radius fractures; Is pronator quadratus muscle repair required after anterior plate fixation for distal radius fractures?; Efficacy of total wrist arthroplasty: a comparative analysis of inflammatory and non-inflammatory arthritis outcomes; A comprehensive review of the one-bone forearm as a salvage technique.

A new species of Agauopsis (Acari, Halacaridae) from South Korea belonging to A. brevipalpus group

A new marine halacarid mite of the genus Agauopsis Viets, 1927 is recorded from mussels in the intertidal bedrock of the southern coast of South Korea. Agauopsis bisetosa n. sp. belonging to the A. brevipalpus group, is characterized by an ‘H’-shaped areola on the anterior dorsal plate, two pairs of costae on the posterior dorsal plate, a tectum with a truncate anterior margin, posterior epimeral plate with two ventral setae, telofemur I with one ventral and two ventromedial dentate spines, and tibia II with one ventral and one ventromedial dentate spines. Notably, the presence of two ventral setae on the posterior epimeral plate is a unique characteristic of the new species. This study deals with a description of A. bisetosa n. sp., accompanied by detailed illustrations drawn under a differential interference contrast microscope and scanning electron microscope photomicrographs. Additionally, it includes a character comparison table of the A. brevipalpus group and a key for known Agauopsis species in the northwest Pacific, both including the new species.

Do all patients with history of pelvic ring injuries need a cesarean section? – A survey of orthopaedic and obstetric providers

Objective(s)The recommended mode of delivery following pelvic ring fractures with surgical fixation is unclear. The objective of this study was to assess expert opinions from orthopaedic surgeons and obstetrician gynecologists on their recommended delivery recommendations for pregnant individuals with a history of pelvic ring injury, and to see if there was any difference in recommendations between the two specialties, and what factors influenced recommendations. Study designAn electronic, web-based survey was administered to a convenience sample of orthopaedic surgeons and obstetrician gynecologists, via advertisement to members of the Orthopaedic Trauma Association (OTA), the Society for Maternal Fetal Medicine, and querying obstetrician gynecologists practicing within the Military Health System. The survey was administered from November 2021 to December 2022. A two-proportion z-test, Chi-square or Fisher's Exact Test, and descriptive statistics were used to analyze data. ResultsSurvey respondents included 44 orthopaedic surgeons and 37 obstetricians. A total of 74 % obstetricians would recommend a trial of labor with hardware in place, while orthopaedic surgeon's recommendations varied based on the type of fixation. Forty four, 100 % of orthopaedic surgeons, recommended trial of labor if non-operative pelvic injury or unilateral posterior fixation only, 88 % recommended trial of labor if bilateral posterior fixation only, and 47.7 % for anterior trans-symphyseal plating only, 50 % for unilateral posterior and trans-symphyseal plating, and 43.2 % for bilateral posterior fixation with trans-symphyseal plating. ConclusionsThe results of these surveys demonstrate the lack of consensus as to the most appropriate birth plan for patients with a history of pelvic ring injuries. Vaginal delivery following pelvic ring fracture and fixation is possible, yet these patients are significantly more likely to undergo cesarean section than the general population. As such, we recommend that women who become pregnant after operative treatment of a pelvic ring injury develop an in-depth birthing plan with their obstetrician to determine the best course.

Treatment of an anterior cervicothoracic myelomeningocele together with spine deformity correction in a child: illustrative case.

Anterior cervicothoracic myelomeningoceles are a rare pathology. In reported cases, treatment has included shunting, isolated resection and repair without deformity correction, or isolated deformity correction without meningocele repair. The authors describe a pediatric patient with an anterior cervicothoracic myelomeningocele presenting with progressive neurological decline, who underwent simultaneous treatment of the myelomeningocele to detether the spinal cord and achieve major correction of the scoliotic deformity. A 15-year-old girl was born with C7-T1-T2 hemivertebrae and anterior cervical myelomeningocele at C7-T1. She developed progressive cervical thoracic scoliosis, left hemiparesis initially, and additional right hemiparesis eventually. She underwent surgical repair via C7, T1, and T2 corpectomies with intradural detethering of the spinal cord. The scoliosis was treated with C7-T2 Ponte osteotomies and C2-T5 posterior fixation, followed by anterior reconstruction with a titanium cage and anterior plate from C6 to T3. The myelomeningocele was adequately treated with good correction of the patient's deformity. The patient had postoperative improvement in her strength and solid arthrodesis on postoperative imaging. The authors describe the successful treatment of an anterior cervicothoracic myelomeningocele and associated scoliosis in a child. This is a unique report of a combined strategy to achieve both deformity correction and detethering of the spinal cord.

Does Anterior Plating of Pelvic Ring Fractures Increase Infection Risk in Patients With Bladder or Urethral Injuries?

Evaluate the effect of anterior fixation on infection in patients with operative pelvic fractures and bladder or urethral injuries. Retrospective. Eight centers. Adult patients with closed pelvic fractures with associated bladder or urethral injuries treated with anterior plating (AP), intramedullary screw (IS), or no anterior internal fixation (NAIF, including external fixation or no fixation). Deep infection. There were 81 extraperitoneal injuries and 57 urethral injuries. There was no difference in infection between fixation groups across all urologic injuries (AP: 10.8%, IS: 0%, NAIF: 4.9%, P = 0.41). There was a higher rate of infection in the urethral injury group compared with extraperitoneal injuries (14.0% vs. 2.5%, P = 0.016). Among extraperitoneal injuries, specifically, there was no difference in deep infection related to fixation (AP: 2.6%, IS 0%, NAIF: 2.9%, P = 0.99). Among urethral injuries, there was no statistical difference in deep infection related to fixation (AP: 23.1%, IS: 0%, NAIF: 7.4%, P = 0.21). There was a higher rate of suprapubic catheter (SPC) use in urethral injuries compared with extraperitoneal injuries (57.9% vs. 4.9%, P < 0.0001). In the urethral injury group, SPC use did not have a statistically significant difference in infection rate (SPC: 18.2% vs. No SPC: 8.3%, P = 0.45). Early removal of the SPC before or during the definitive orthopaedic intervention did not significantly affect infection rate (early: 0% vs. delayed: 25.0%, P = 0.16). Surgeons should approach operative pelvic fractures with associated urologic injuries with caution given the high risk of infection. Further work must be done to elucidate the effect of anterior implants and SPC use and duration. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Clinical and Radiographic Outcomes of Anterior Lumbar Interbody Fusion With Anterior Plate Fixation.

Reports on the outcomes following instrumented anterior lumbar interbody fusion (ALIF) with anterior plate fixation are limited. The aim of this study was to assess the clinical and radiographic outcomes of patients undergoing ALIF with anterior plate fixation. Methods: Medical records and radiographic imaging were reviewed for 100 patients who received ALIF with anterior plate fixation between 2008 to 2021 and completed at least one year of follow-up and postoperative imaging. Prospectively collected patient data included indication for surgery, BMI, age, number and location of levels treated, complications, reoperation rates, fusion rate, and measurements of global lordosis, disc space height, and segmental angulation. Results: A total of 100 patients were included in this study. The mean length of follow-up was 81.37 months. Changes in preoperative-to-postoperative Oswestry Disability Index (ODI) and Visual Analog Score (VAS) demonstrated improvements of 30.86% and 18.56%, respectively. Major vascular injuries occurred in 3% of the cases. A hardware failure rate of 5% was observed. The reoperation rate was 10%. The radiographic fusion rate derived from computed tomography (CT) and plain film was 95.45% and 88.87%, respectively. Postoperative global lordosis demonstrated a 6.08% increase. Postoperative segmental angulation measurements increased by 57.74%. No statistically significant differences in clinical or radiographic outcomes were observed based on the spine level of fusion or the number of fusions performed. Conclusions: ALIF with anterior plate fixation achieved an adequate fusion rate with improvements in ODI and VAS scores meeting minimal clinically important difference thresholds. Postoperative disc space heights demonstrated significant improvements compared to preoperative measurements.

Combined home and clinic-based therapy versus home-based exercise programme after distal radial fracture: a randomized controlled study.

We investigated outcomes of clinic-based hand therapy combined with a home-based exercise programme after anterior plating for distal radial fractures. A total of 102 patients were randomly assigned to one of three groups: a home-based exercise programme alone; a home-based exercise programme combined with four hand therapy sessions in the clinic; and a home-based exercise programme with seven sessions in the clinic. Mean Patient-Rated Wrist Evaluation scores at 6 weeks were significantly better for the group of patients with seven sessions in the clinic than in those with only home exercises (12 vs. 30), but the difference was no longer significant at 12 weeks. Grip strength was significantly better at 6 and 12 weeks. Combined home- and clinic-based hand therapy may facilitate an earlier return of function after anterior plating for distal radius fractures.Level of evidence: II.

Xenopus Sox11 Partner Proteins and Functional Domains in Neurogenesis.

Sox11, a member of the SoxC family of transcription factors, has distinct functions at different times in neural development. Studies in mouse, frog, chick, and zebrafish show that Sox11 promotes neural fate, neural differentiation, and neuron maturation in the central nervous system. These diverse roles are controlled in part by spatial and temporal-specific protein interactions. However, the partner proteins and Sox11-interaction domains underlying these diverse functions are not well defined. Here, we identify partner proteins and the domains of Xenopus laevis Sox11 required for protein interaction and function during neurogenesis. Our data show that Sox11 co-localizes and interacts with Pou3f2 and Neurog2 in the anterior neural plate and in early neurons, respectively. We also demonstrate that Sox11 does not interact with Neurog1, a high-affinity partner of Sox11 in the mouse cortex, suggesting that Sox11 has species-specific partner proteins. Additionally, we determined that the N-terminus including the HMG domain of Sox11 is necessary for interaction with Pou3f2 and Neurog2, and we established a novel role for the N-terminal 46 amino acids in the specification of placodal progenitors. This is the first identification of partner proteins for Sox11 and of domains required for partner-protein interactions and distinct roles in neurogenesis.

Biomechanical Comparison of Anterior Cervical Corpectomy Decompression and Fusion, Anterior Cervical Discectomy and Fusion, and Anterior Controllable Antedisplacement and Fusion in the Surgical Treatment of Multilevel Cervical Spondylotic Myelopathy: A Finite Element Analysis.

Multilevel cervical spondylotic myelopathy poses significant challenges in selecting optimal surgical approaches, warranting a comprehensive understanding of their biomechanical impacts. Given the lack of consensus regarding the most effective technique, this study aims to fill this critical knowledge gap by rigorously assessing and comparing the biomechanical properties of three distinct surgical interventions, including anterior controllable antedisplacement and fusion (ACAF), anterior cervical corpectomy decompression and fusion (ACCF), and anterior cervical discectomy and fusion (ACDF). The study offers pivotal insights to enhance treatment precision and patient outcomes. The construction of the cervical spine model involved a detailed process using CT data, specialized software (Mimics, Geomagic Studio, and Hypermesh) and material properties obtained from prior studies. Surgical instruments were modeled (titanium mesh, anterior cervical plate, interbody cage, and self-tapping screws) to simulate three surgical approaches: ACAF, ACCF, and ACDF, each with specific procedures replicating clinical protocols. A 75-N follower load with 2 Nm was applied to simulate biomechanical effects. The range of motion decreased more after surgery for ACAF and ACDF than for ACCF, especially in flexion and lateral bending. ACCF have higher stress peaks in the fixation system than those of ACAF and ACDF, especially in flexion. The maximum von Mises stresses of the bone-screw interfaces at C3 of ACCF were higher than those of ACAF and ACDF. The maximum von Mises stresses of the bone-screw interfaces at C6 of ACDF were much higher than those of ACAF and ACCF. The maximum von Mises stresses of the grafts of ACCF and ACAF were much higher than those of ACDF. The maximum von Mises stresses of the endplate of ACCF were much higher than those of ACAF and ACDF. The ACAF and ACDF models demonstrated superior cervical reconstruction stability over the ACCF model. ACAF exhibited lower risks of internal fixation failure and cage subsidence compared to ACCF, making it a promising approach. However, while ACAF revealed improved stability over ACCF, higher rates of subsidence and internal fixation failure persisted compared to ACDF, suggesting the need for further exploration of ACAF's long-term efficacy and potential improvements in clinical outcomes.

The Role of Osteobiologics in Augmenting Spine Fusion in Unplated Anterior Cervical Discectomy and Fusion Compared to Plated Constructs: A Systematic Review and Meta-analysis.

Systematic review and meta-analysis. To compare clinical and radiographic outcomes as well as complications of unplated vs plated anterior cervical discectomy and fusion (ACDF) surgery considering the role of osteobiologics in single- and multi-level procedures. A systematic search of PubMed/MEDLINE, Scopus, CINAHL, EMBASE, CENTRAL, Cochrane and ClinicalTrials.gov databases was performed. Briefly, we sought to identify studies comparing unplated vs. plated ACDF for cervical degenerative disc disease reporting the use of osteobiologics in terms of clinical outcomes, radiographic fusion, and complications. Data on study population, follow-up time, type of cage and plate used, type of osteobiologic employed, number of levels treated, patient-reported outcomes (PROs), radiographic outcomes and complications were collected and compared. Relevant information was pooled for meta-analyses. Thirty-eight studies met the inclusion criteria. No significant difference was found in terms of clinical outcomes between groups. Unplated ACDF was characterized by reduced blood loss, operation time and length of hospital stay. Fusion was achieved by the majority of patients in both groups, with no evidence of any specific contribution depending on the osteobiologics used. Dysphagia was more commonly associated with anterior plating, while cage subsidence prevailed in the unplated group. Unplated and plated ACDF seem to provide similar outcomes irrespective of the osteobiologic used, with minor differences with doubtful clinical significance. However, the heterogeneity and high risk of bias affecting included studies markedly prevent significant conclusions.

New morphological data for two rare species of sand-dwelling marine dinoflagellates, Amphidiniella sedentaria and Pachena cf. leibnizii

Abstract Benthic dinoflagellates have been the subject of extensive taxonomic research in recent decades. Studies of morphologies of already known species of benthic dinoflagellates from various geographical populations remain relevant, as these allow elucidation of some details that were overlooked in the original species descriptions or assessment of their morphological variability. In the present study, two rare species of dinoflagellates, Amphidiniella sedentaria and Pachena cf. leibnizii, have been studied, for the first time, from coastal sands of the northwestern Sea of Japan. In the cells of A. sedentaria from the Sea of Japan, we have found two anterior intercalar plates instead of one. Therefore, the original formula has been changed to APC 4′ 2a 7″ 5c 4s 6‴ 2⁗. As a result of the examination of P. cf. leibnizii from the Sea of Japan, we have counted seven precingular plates and six cingular plates, instead of six and five, respectively, indicated in the original description. The plate formula of the cells of P. cf. leibnizii from the Sea of Japan is APC 4′ 3a 7″ 6c 5s 5‴ 2⁗. It is currently difficult to judge whether these differences are morphological variations. Therefore, we have identified these cells as P. cf. leibnizii.

New investigation of the cyst–motile relationship for Votadinium spinosum reveals a Protoperidinium claudicans species complex (Dinophyceae, Peridiniales)

Protoperidinium claudicans is a planktonic, heterotrophic, bioluminescent dinoflagellate species commonly found in neritic waters. It has long been considered to display phenotypic variation in its second anterior intercalary plate, which could vary between quadra, penta and hexa. The equivalent spinose, cordate cyst goes under the name of Votadinium spinosum. Here we perform incubation experiments with cysts from France, Canada, China and Japan, which demonstrate that P. claudicans forms a species complex, with at least two ribotypes with a penta configuration (P. claudicans) and one with a quadra configuration (P. carriae sp. nov.). A fossil-based cyst, V. multispinosum sp. nov., is described as the equivalent of P. carriae. Molecular phylogenetics using large subunit ribosomal DNA supports these observations. The cyst–theca relationships for Votadinium psilodora and another, undescribed, cordate, spineless Votadinium species are also reported from China. Macromolecular analyses of the cyst wall of V. multispinosum reveal it is comprised of a protein-rich carbohydrate compound. We show that this compound is not uncommon in dinoflagellate and ciliate cysts and that it is unlikely to preserve very well upon sedimentation and burial.

Does plate position influence the outcome in midshaft clavicular fractures? A multicenter analysis

PurposeTo date, it remains unclear whether superior or anterior plating is the best option for treating midshaft clavicular fractures. The aim of this study was to compare both techniques with regard to the incidence of implant removal due to implant irritation, risk of complications, time to union, and function.MethodsIn this retrospective cohort study, all midshaft clavicular fractures treated operatively between 2017 and 2020 in two hospitals in Switzerland were analyzed. The participating hospitals differed with regard to their standard practice; one offered superior plating only, while the other predominantly employed an anterior plate. The primary outcome was the incidence of implant removal for irritation. Secondary outcomes were time to union, complications, re-interventions, and range of motion during the follow-up period of at least 6 months.ResultsIn total, 168 patients were included in the study of which 81 (48%) received anterior plating and 87 (52%) superior plating. The overall mean age was 45 years (SD 16). There was no significant difference between anterior and superior plating with regard to implant removal (58.5% versus 57.1%, p = 0.887), infection (5.7% versus 1.8%, p = 0.071), and time to union (median 48 weeks versus 52 weeks, p = 0.643). Data on range of motion were available in 71 patients. There was no significant difference in anteflexion (median 180 degrees anterior versus 180 degrees superior) and abduction (median 180 degrees anterior versus 180 degrees superior) between the two groups.ConclusionThis retrospective cohort study did not find sufficient evidence to recommend one implant position over the other for midshaft clavicular fractures with regard to removal due to irritation. Time to union was similar and Infections were equally rare in both groups. Notably, a considerable number of patients in both groups had their implants removed due to irritation. Larger prospective studies are needed to determine how much plate position contributes to the occurrence of irritation and whether other patient or implant-related factors might play a role. Until this is clarified, implant position should be based on surgeons preference and experience.

NEW-GENERATION SUPERIOR SINGLE PLATING VERSUS LOW-PROFILE DUAL MINI-FRAGMENT PLATING OF DIAPHYSEAL CLAVICLE FRACTURES: A BIOMECHANICAL STUDY

Recently, a new generation of superior clavicle plates was developed featuring the variable-angle locking technology for enhanced screw positioning and optimized plate-to-bone fit design. On the other hand, mini-fragment plates used in dual plating mode have demonstrated promising clinical results. However, these two bone-implant constructs have not been investigated biomechanically in a human cadaveric model. Therefore, the aim of the current study was to compare the biomechanical competence of single superior plating using the new generation plate versus dual plating with low-profile mini-fragment plates.Sixteen paired human cadaveric clavicles were assigned pairwise to two groups for instrumentation with either a 2.7 mm Variable Angle Locking Compression Plate placed superiorly (Group 1), or with one 2.5 mm anterior plate combined with one 2.0 mm superior matrix mandible plate (Group 2). An unstable clavicle shaft fracture AO/OTA15.2C was simulated by means of a 5 mm osteotomy gap. All specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis and monitored via motion tracking.Initial stiffness was significantly higher in Group 2 (9.28±4.40 N/mm) compared to Group 1 (3.68±1.08 N/mm), p=0.003. The amplitudes of interfragmentary motions in terms of craniocaudal and shear displacement, fracture gap opening and torsion were significantly bigger over the course of 12500 cycles in Group 1 compared to Group 2; p≤0.038. Cycles to 2 mm shear displacement were significantly lower in Group 1 (22792±4346) compared to Group 2 (27437±1877), p=0.047.From a biomechanical perspective, low-profile 2.5/2.0 dual plates demonstrated significantly higher initial stiffness, less interfragmentary movements, and higher resistance to failure compared to 2.7 single superior variable-angle locking plates and can therefore be considered as a useful alternative for diaphyseal clavicle fracture fixation especially in unstable fracture configurations.

Ceciamaralia, a new genus of Dorvilleidae (Annelida) from deep waters of the Southwest Atlantic Ocean and an insight into its relationship within the family.

Dorvilleidae Chamberlin, 1919 is a family of Annelida containing some of the smallest 'polychaetes' species, being poorly studied worldwide, and with little knowledge regarding its diversity and occurrence. Samples obtained in oceanographic campaigns performed in the Southwest Atlantic Ocean (Brazilian coast) revealed a high number of specimens of dorvilleids, adding to our knowledge of the family's biodiversity. A detailed morphological analysis of these organisms has revealed a new genus, Ceciamaralia gen. nov., with two new species. The new genus differs from other Dorvilleidae genera in (i) the robust and enlarged pharynx which are frequently everted, (ii) unique composition of maxillae, with an elongated pair of serrated basal plates and one pair of anterior free maxillary plates with a long and thin anterior spine and (iii) ventral cirri present only in few first chaetigers. Ceciamaralia lanai gen. et sp. nov. is characterized by the presence of a broad and large dorsal cirrus on a few anterior parapodia and by furcate chaeta in supra-acicular fascicles. While Ceciamaralia nonatoi gen. et sp. nov. presents one geniculate chaeta instead of one furcate, the absence of dorsal cirri and, in some specimens, the absence of palps. A cladistic analysis supported the monophyly of Ceciamaralia gen. nov. by four synapomorphies related to the unique morphology of its maxillae, pharynx and appendages. This study is part of several recent taxonomic studies aiming to elucidate and increase the knowledge of Dorvilleidae, since it is part of a Ph.D project focused on the family.

A Brief Review on PEEK as biomaterial, Importance of Implant Design, 3D Printing and FEA in Dental Implant

The present research study seeks to provide a thorough literature evaluation on implant-based materials, implant design and application of FEA approach (Finite Element Analysis). PEEK biomaterial is the primary subject of this article. Implant design and the significance of PEEK material in future clinical applications are significant subtopics in this study. Due to its excellent physical qualities, titanium plays an essential part in the implant business. PEEK and zirconia materials appear to have promise for the future. Biomedical uses of PEEK and its composite materials in a number of different fields, including dentistry, hip implant, anterior plate fixation, crainoplasticity, knee implants, spine implants, and so forth. The implant's impact and success are greatly impacted by the prudent selection of implant biomaterial. Before the PEEK implant can replace titanium and zirconium, further research and well-controlled clinical studies are required. In this study, a number of biomaterials that were used in the implant industry will be finalized.