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Solid-state lithium metal batteries (SSLMBs) are a promising energy storage technology, but challenges persist including electrolyte thickness and lithium (Li) dendrite puncture. A novel three-dimensional "peapod-like" composite solid electrolyte (CSEs) with low thickness (26.8 µm), high mechanical strength, and dendrite inhibition was designed. Incorporating Li7La3Zr2O12 (LLZO) enhances both mechanical strength and ionic conductivity, stabilizing the CSE/Li interface and enabling Li symmetric batteries to stabilize for 3000 h. With structural advantages, the assembled LFP||Li and NCM811||Li cells exhibit excellent cycling performance. In addition, the constructed NCM811 pouch cell achieves a high gravimetric/volumetric energy density of 307.0 Wh kg-1/677.7 Wh L-1, which can light up LEDs under extreme conditions, demonstrating practicality and high safety. This work offers a generalized strategy for CSE design and insights into high-performance SSLMBs.
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Hard carbon (HC) is a promising anode candidate for Na-ion batteries (NIBs) because of its excellent Na-storage performance, abundance, and low cost. However, a precise understanding of its Na-storage behavior remains elusive. Herein, based on the D2O/H2SO4-based TMS results collected on charged/discharged state HC electrodes, detailed Na-storage mechanisms (the Na-storage states and active sites in different voltage regions), specific SEI dynamic evolution process (formation, rupture, regeneration and loss), and irreversible capacity contribution (dead Na0, NaH, etc.) were elucidated. Moreover, by employing the online electrochemical mass spectrometry (OEMS) to monitor the gassing behavior of HC-Na half-cell during the overdischarging process, a surprising rehydrogen evolution reaction (re-HER) process at around 0.02 V vs Na+/Na was identified, indicating the occurrence of Na-plating above 0 V vs Na+/Na. Additionally, the typical fluorine ethylene carbonate (FEC) additive was demonstrated to reduce the accumulation of dead Na0 and inhibit the re-HER process triggered by plated Na.
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A functional coating layer (FCL) is widely applied in fast-charging lithium-ion batteries to improve the sluggish Li+ transport kinetics of traditional graphite anodes. However, blindly increasing the Li+ conductivity for FCL reduces the overall electron conductivity of the anodes. Herein, we decoupled the effect of La-doping on TiNb2O7 (TNO) in terms of the phase evolution, Li+/electron transport, and lithiation behavior, and then proposed a promising La0.1TNO FCL with balanced Li+/electron transport for a fast-charging graphite anode. By optimizing the doping concentration of La, more holes are introduced into the TNO as electron carriers without causing lattice distortion, thus maintaining the fast Li+ diffusion channel in TNO. As a result, the graphite with La0.1TNO FCL delivers an excellent capacity of 220.2 mAh g-1 (96.3% retention) after 450 cycles at 3 C, nearly twice that of the unmodified one.
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Lithium (Li) metal is widely recognized as a viable candidate for anode material in future battery technologies due to its exceptional energy density. Nevertheless, the commercial Li foils in common use are too thick (≈100 µm), resulting in a waste of Li resources. Herein, by applying the vacuum evaporation plating technology, the ultra-thin Li foils (VELi) with high purity, strong adhesion, and thickness of less than 10 µm are successfully prepared. The manipulation of evaporation temperature allows for convenient regulation of the thickness of the fabricated Li film. This physical thinning method allows for fast, continuous, and highly accurate mass production. With a current density of 0.5 mA cm-2 for a plating amount of 0.5 mAh cm-2, VELi||VELi cells can stably cycle for 200 h. The maximum utilization of Li is already more than 25%. Furthermore, LiFePO4||VELi full cells present excellent cycling performance at 1 C (1 C = 155 mAh g-1) with a capacity retention rate of 90.56% after 240 cycles. VELi increases the utilization of active Li and significantly reduces the cost of Li usage while ensuring anode cycling and multiplication performance. Vacuum evaporation plating technology provides a feasible strategy for the practical application of ultra-thin Li anodes.
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Lithium metal-based rechargeable batteries are attracting increasing attention due to their high theoretical specific capacity and energy density. However, the dendrite growth leads to short circuits or even explosions and rapid depletion of active materials and electrolytes. Here, a functionalized and laminated scaffold (PVDF/TiO@C fiber) based on lithiophilic titanium monoxide is rationally designed to inhibit dendrite growth. Specifically, the bottom TiO@C fiber sublayer provides rich Li nucleation sites and facilitates the formation of stable solid electrolyte interphase. Together with the top lithiophobic PVDF sublayer, the prepared freestanding scaffold can effectively suppress the growth of Li dendrite and ensure stable Li plating/stripping. Based on the dendrite-free deposition, the Li/PVDF/TiO@ C fiber anode enables over 1000 h at a current density of 1 mA cm-2 in a symmetrical cell and delivers superior electrochemical performance in both Li || LFP and Li-S batteries. The functional laminated fiber scaffold design provides essential insights for obtaining high-performance lithium metal anodes.
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Localized high-concentration electrolytes (LHCEs) have emerged as a promising class of electrolytes to improve the cycle life and energy density of lithium-ion batteries (LIBs). While their application in batteries with lithium-metal anodes is extensively investigated, their behavior in systems with graphite anodes has received less research attention. Herein, the behaviors of four electrolytes in Graphite | LiNiO2 cells are compared. By systematically varying the electrolyte compositions, the impacts of the solvation structure, solvent composition, and salt composition of LHCEs are identified on the rate capability, stability, and propensity for lithium plating in LIB full-cells. It is found that while the solvation structure and solvent composition each play an important role in determining rate capability, the substitution of LiPF6 salt with LiFSI maximizes the rate capability and suppresses irreversible lithium plating. It is now demonstrated via constant-potential cycling, that an appropriately formulated LHCE can, therefore, maintain high reversible capacity and safety under arbitrarily fast charging conditions.
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INTRODUCTION: Prior work has demonstrated utility in using operative time to measure surgeon learning for surgical stabilization of rib fractures (SSRF); however, no studies have used operative time to evaluate the benefit of proctoring in subsequent generations of surgeons. We sought to evaluate whether there is a difference in learning between an original series (TOS) of self-taught surgeons versus the next generation (TNG) of proctored surgeons using cumulative summation (CUSUM) analysis. We hypothesized that TNG would have a comparatively accelerated learning curve. METHODS: A single-center retrospective review of all SSRF at a level 1 trauma center was performed. Data were collected from the beginning of an operative chest injury program to include at least 2 y of TNG experience. Operative time was used to determine success and misstep based on prior methods. Learning curves using CUSUM analysis were calculated based on an anticipated success rate of 90% and compared between TOS and TNG groups. RESULTS: Over 7 y, 163 patients with a median Injury Severity Score of 24 underwent SSRF. Median operative time was 165 min with a 0.5 plate-to-fracture ratio. All three TOS surgeons experienced a positive slope indicative of early missteps for their first 15-20 cases. By contrast, all three TNG surgeons demonstrated a series of early successes resulting in negative CUSUM slopes which coincided with a period of proctoring. By the end of TNG series, the composite cumulative score was less than half of the TOS surgeon' scores. CONCLUSIONS: Operative time continues to be a useful surrogate for observing SSRF learning curves. In a mature institutional program, proctored novice surgeons appear to have an accelerated learning curve compared to novice surgeons developing a new operative rib program.
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This paper describes the simple and label-free detection of thrombin using optical fiber surface plasmon resonance (SPR) sensors based on gold films prepared by the cost-effective method of electroless plating. The plating conditions for simultaneously obtaining gold film on cylindrical core and end surfaces of an optical fiber suitable for measurement were optimized. The fabricated sensor exhibited a linear refractive index sensitivity of 2150 nm/RIU and 7.136 (a.u.)/RIU in the refractive index of 1.3329-1.3605 interrogated by resonance wavelength and amplitude methods respectively and a single wavelength monitoring method was proposed to investigate the sensing performance of this sensor. Polyadenine diblock and thiolated thrombin aptamers were immobilized on gold nanoparticles and gold films respectively to implement a sandwich optical fiber assay for thrombin. The developed optical fiber SPR sensors were successfully used in the determination of thrombin down to 0.56 nM over a wide range from 2 to 100 nM and showed good selectivity for thrombin, which indicated their potential clinical applications for biomedical samples.
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Técnicas Biossensoriais , Nanopartículas Metálicas , Ressonância de Plasmônio de Superfície/métodos , Fibras Ópticas , Técnicas Biossensoriais/métodos , Ouro , TrombinaRESUMO
Spermatogonia cryopreservation can be a strategy for future conservation actions. The neotropical Siluriformes Pseudopimelodus mangurus was already classified as vulnerable on the Red List of Threatened Species. P. mangurus spermatogonial cells were isolated, assessed, and cryopreserved. Fragments of the testis were enzymatically dissociated, purified using Percoll density gradient, and submitted to differential plating. Fractionated cells were evaluated by microscopy, ddx4 (vasa) relative expression, and alkaline phosphatase activity. Cryopreservation was conducted using ethylene glycol, glycerol, dimethyl sulfoxide (DMSO), dimethylacetamide (DMA), and propanediol at 1 M, 1.5 M, and 2 M. Cell viability was evaluated and cell concentration was determined. Cell fractions from 20 % and 30 % Percoll gradient bands showed the highest concentrations of spermatogonia. The fraction mix showed 54 % purity and 93 % viability. After differential plating, 60 % purity and 92 % viability were obtained. Spermatogonial cells showed high alkaline phosphatase activity compared to spermatocytes and spermatids. The relative spermatogonial ddx4 expression from the Percoll density gradient was about twice as high as in samples from the testis and the differential plating. The increased ddx4 expression indicated the enrichment of spermatogonial cells by density gradient step and dead cells expressing ddx4 in differential plating, or ddx4 decreasing expression during cell culture. For this reason, cells from the Percoll gradient were chosen for cryopreservation. Propanediol at 1 M demonstrated the best condition for spermatogonial cell cryopreservation, presenting 98 % viability, while dimethylacetamide at 2 M represented the least favorable condition, with approximately 47 % viability. These findings are essential for P. mangurus spermatogonial cell cryopreservation, aiming to generate a spermatogonia cryobank for future conservation efforts.
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BACKGROUND: This study was designed to explore the clinical efficacy of 3-dimensional (3D) printing assisted minimally invasive percutaneous plate osteosynthesis (MIPO) technique by comparing the clinical outcomes with traditional open reduction and internal plating fixation (ORIF) for treating complex middle-proximal humerus fractures (AO 12C fracture type). MATERIALS AND METHODS: The data of 42 participants who received a complicated middle-proximal humerus fracture from the beginning of 2018 to the end of 2022 were retrospectively analyzed. All patients were assigned to two groups: MIPO with detailed preoperative planning assisted by 3D printing technique (MIPO group), and traditional ORIF (ORIF group). RESULTS: This study included 21 patients in the ORIF group and 21 patients in the MIPO group. All patients were followed-up for at least one year (mean: 16.12 ± 4.13 months), and no difference was observed in the range of shoulder joint motion (ROM), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores and Constant scores between the two groups. However, the occurrence of complications (surgical incision site infection, implant loosening, bone nonunion and radial nerve palsy) in ORIF group was remarkably higher compared to the MIPO group. All the cases achieved bone union within the MIPO group. Significant differences were found in surgical time, intraoperative blood loss and fracture healing time between the two groups. CONCLUSION: Preoperative 3D printing assisted MIPO technique exhibits obvious advantages in high operational efficiency and low occurrence of complications, which is worthy of clinical application for treating complex middle-proximal humeral shaft fractures.
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Perda Sanguínea Cirúrgica , Fraturas do Ombro , Humanos , Estudos Retrospectivos , Placas Ósseas , Impressão Tridimensional , Úmero/diagnóstico por imagem , Úmero/cirurgiaRESUMO
INTRODUCTION: Many distal humerus nonunions are associated with bone loss and rigid internal fixation is difficult to obtain, especially for low transcondylar nonunions and those with severe intraarticular comminution. The purpose of this study was to analyze the results of a strategy to address this challenge utilizing internal fixation using the Supracondylar Ostectomy + Shortening (i.e. S.O.S.) procedure for distal humerus nonunions. The goals of this procedure are to (1) optimize bony contact and compression through re-shaping the nonunited fragments at the supracondylar level with selective humeral metaphyseal shortening, (2) maximize fixation using parallel-plating, and (3) provide biologic and structural augmentation with bone graft. MATERIALS AND METHODS: Between 1995 and 2019, 28 distal humerus nonunions underwent internal fixation using the S.O.S. procedure at a single Institution. There were 14 males and 14 females with mean age of 47 (range 14-78) years at the time of the S.O.S procedure and an average of 1.7 prior surgeries. Medical records and radiographs were reviewed to determine rates of union, reoperations, complications, and Mayo Elbow Performance Scores (MEPS). Patients were also prospectively contacted to update their MEPS and gather additional information on complications and reoperations. Mean clinical exam follow-up was 17 months, mean clinical contact follow-up was 19 months, and mean radiographic follow-up was 32 months. RESULTS: Four patients did not have adequate follow-up to determine union. Of the remaining 24 elbows, 22 achieved union. Two elbows developed collapse of the articular surface and were converted to a total elbow arthroplasty (TEA). There were complications in 10 elbows: contracture (5), superficial infection (2), ulnar neuropathy (1), deep infection (1), and hematoma (1). Twelve elbows underwent reoperation: 4 for contracture release, 3 for hardware removal, 2 for total elbow arthroplasty, 1 for bone grafting, 1 for hematoma evacuation, and 1 for ulnar nerve neurolysis. Compared to preoperative data, there was a significant improvement in postoperative flexion, extension and pronation (p<0.01). The mean range of motion was 21° of extension, 119° of flexion, 79° of pronation, and 77° of supination. The mean MEPS was 80 points (range, 25 to 100 points) and 19 elbows (76%) rated as excellent or good. DISCUSSION: Stable fixation and high union rates are possible in distal humerus nonunions with bone loss using a technique that combines supracondylar humeral shortening, parallel plating, and bone grafting. Secondary procedures are commonly needed to restore function in this challenging patient population.
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BACKGROUND: Recently, a new generation of superior clavicle plates was developed featuring the variable-angle locking technology for enhanced screw positioning and a less prominent and optimized plate-to-bone fit design. On the other hand, minifragment plates in dual plating mode have demonstrated promising clinical results. The aim of the current study was to compare the biomechanical competence of single superior plating using the new-generation plate vs. dual plating using low-profile minifragment plates. METHODS: Sixteen paired human cadaveric clavicles were pairwise assigned to 2 groups for instrumentation with either a superior 2.7-mm variable-angle locking compression plate (group 1), or with one 2.5-mm anterior combined with one 2.0-mm superior matrix mandible plate (group 2). An unstable clavicle shaft fracture (AO/OTA 15.2C) was simulated by means of a 5-mm osteotomy gap. Specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis, and monitored via motion tracking. RESULTS: Initial construct stiffness was significantly higher in group 2 (9.28 ± 4.40 N/mm) compared to group 1 (3.68 ± 1.08 N/mm), P = .003. The amplitudes of interfragmentary motions in terms of axial and shear displacement, fracture gap opening and torsion, over the course of 12,500 cycles were significantly higher in group 1 compared to group 2, P ≤ .038. Cycles to 2 mm shear displacement were significantly lower in group 1 (22,792 ± 4346) compared to group 2 (27,437 ± 1877), P = .047. CONCLUSION: From a biomechanical perspective, low-profile 2.5/2.0-mm dual plates could be considered as a useful alternative for diaphyseal clavicle fracture fixation, especially in less common unstable fracture configurations.
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Clavícula , Fraturas Ósseas , Humanos , Clavícula/cirurgia , Fenômenos Biomecânicos , Fraturas Ósseas/cirurgia , Fixação Interna de Fraturas/métodos , Parafusos Ósseos , Placas ÓsseasRESUMO
Aluminum (Al) metal is an attractive anode material for next-generation rechargeable batteries, because of its low cost and high capacities. However, it brings some fundamental issues such as dendrites, low Coulombic efficiency (CE), and low utilization. Here, we propose a strategy for constructing an ultrathin aluminophilic interface layer (AIL) to regulate the Al nucleation and growth behaviors, which enables highly reversible and dendrite-free Al plating/stripping under high areal capacity. Metallic Al can maintain stable plating/stripping on the Pt-AIL@Ti for over 2000 h at 10 mAh cm-2 with an average CE of 99.9%. The Pt-AIL also enables reversible Al plating/stripping at a record high areal capacity of 50 mAh cm-2, which is 1-2 orders of magnitude higher than the previous studies. This work provides a valuable direction for further construction of high-performance rechargeable Al metal batteries.
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The prominent problem with graphite anodes in practical applications is the detrimental Li plating, resulting in rapid capacity fade and safety hazards. Herein, secondary gas evolution behavior during the Li-plating process was monitored by online electrochemical mass spectrometry (OEMS), and the onset of local microscale Li plating on the graphite anode was precisely/explicitly detected in situ/operando for early safety warnings. The distribution of irreversible capacity loss (e.g., primary and secondary solid electrolyte interface (SEI), dead Li, etc.) under Li-plating conditions was accurately quantified by titration mass spectroscopy (TMS). Based on OEMS/TMS results, the effect of typical VC/FEC additives was recognized at the level of Li plating. The nature of vinylene carbonate (VC)/fluoroethylene carbonate (FEC) additive modification is to enhance the elasticity of primary and secondary SEI by adjusting organic carbonates and/or LiF components, leading to less "dead Li" capacity loss. Though VC-containing electrolyte greatly suppresses the H2/C2H4 (flammable/explosive) evolution during Li plating, more H2 is released from the reductive decomposition of FEC.
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INTRODUCTION: This study described a deformity induced by medial plating of supracondylar distal femur fractures using plates that are precontoured for other anatomic locations. MATERIALS AND METHODS: OTA/AO 33A fractures were created in 12 sawbone femurs and fixed with either a proximal humerus locking plate (PH), an ipsilateral lateral tibial plateau plate (LTP), or an ipsilateral medial distal tibial plate (MDT). A motion capture system measured changes in length and rotation of the distal femur as the plate was applied. Each plate underwent four trials and the mean and standard deviation (SD) for each measurement was reported. An analysis of variance with post hoc Tukey test compared malreduction measures between plate types. RESULTS: All plates consistently created a varus deformity. There was lateral lengthening with a compensatory medial shortening and an increase in the lateral distal femoral angle. The distal fracture fragment was laterally translated, and internally rotated. The PH plate had significantly greater lateral length (27.39 mm SD 4.78, p = 0.007), shorter medial length (13.57 mm SD 4.99, p = 0.028), greater lateral translation (28.82 mm SD 5.70, p = 0.010) and greater widening of the lateral distal femoral angle (28.54° SD 4.98, p < 0.001) than the LTP and MDT plates. The MDT plate had significantly greater angulation anteriorly (8.40° SD 1.07, p < 0.001) and laterally (7.63° SD 3.10, p = 0.002) than the PH and LTP plates. There was no significant difference between plates in internal rotation (PH: 3.07° SD 2.79; LTP: 2.05° SD 1.05; MDT 3.81° SD 3.56; p = 0.659). CONCLUSION: When dual plating supracondylar distal femur fractures, poor plate positioning and a mismatch between plate contour and the slope of the medial distal femur can lead to varus angulation, internal rotation, and lateral translation or a "reverse golf club deformity". After comparing three types of precontoured plates, the authors recommend initial evaluation of the ipsilateral proximal tibial plate when placing a plate along the medial distal femur. LEVEL OF EVIDENCE: IV.
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Fraturas Femorais Distais , Fraturas do Fêmur , Golfe , Humanos , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas , Fêmur , Placas ÓsseasRESUMO
INTRODUCTION: Distal radius fractures are the most commonly reported fractures in adults. Treatment has changed in recent years to open reduction and palmar plate fixation. Penetration of the dorsal screw, however, is a well-known complication. Intraoperative anteroposterior and lateral radiographs lack the exact assessment of dorsal screw length and intraoperative measurement is therefore very likely to be inaccurate in a comminuted dorsal radial cortex. Secondary extensor tendon ruptures are reported in up to 6% following palmar plate fixation of distal radius fracture. MATERIALS AND METHODS: A prospective randomized trial was performed to assess the value of the dorsal horizon view. The hypothesis was that the traditional anteroposterior and lateral fluoroscopic views aided by an axial view of the dorsal part of the radius, named dorsal horizon view, could prevent dorsal screw penetration. A total of 40 patients, 6 male and 34 female, were included in the study. Standardized anteroposterior and lateral radiographs were performed intraoperatively in 18 patients (standard group = control group). In 22 patients, intraoperative axial fluoroscopic views (dorsal horizon view) were added to anteroposterior and lateral images (horizon group). Numbers of intraoperative screw changes due to the two different radiological examinations were analyzed as well as exact postoperative CT guided measurement of screw length. RESULTS: The total numbers of intraoperative screw changes were significantly higher in the horizon group. Forty-two screws were changed in 15 patients in the horizon group while only 8 screws were changed in 3 patients in the standard group. Postoperative computed tomography scans showed significantly lower total numbers of perforating screws in the horizon group with 11 screws in 22 patients compared to 20 screws in 18 patients in the standard group (p = 0.02). CONCLUSIONS: Based on the results of this study, the dorsal horizon view improves the assessment of the correct screw length and should routinely be used in palmar plate osteosynthesis of distal radius fractures. Since screw protrusion cannot be absolutely ruled out using the dorsal horizon view, monocortical drilling or screw downsizing is still mandatory. TRIAL REGISTRATION: This clinical trial was not registered because it was a clinical examination without any experimental techniques.
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Placa Palmar , Fraturas do Rádio , Fraturas do Punho , Adulto , Humanos , Masculino , Feminino , Fraturas do Rádio/diagnóstico por imagem , Fraturas do Rádio/cirurgia , Placa Palmar/cirurgia , Estudos Prospectivos , Placas Ósseas , Fixação Interna de Fraturas/métodos , Parafusos ÓsseosRESUMO
OBJECTIVE: The role of concomitant fibula fracture fixation in distal-third tibia fractures regarding alignment, union, and functional outcome is still a topic of debate. In this review, we summarize the available comparative literature regarding fibula fixation in distal third lower leg fractures. MATERIALS AND METHODS: A systematic literature review of articles published between January 2000 and January 2022 in the PubMed, Cochrane, and EMBASE databases about this topic was performed. RESULTS: 746 unique studies were identified of which four randomized-controlled trials and six retrospective studies were included. Nine studies compared alignment after tibia fixation with or without fibula fixation, six studies reported on tibial union, and three studies reported on functional outcome between groups. Pooling of data was not possible due to varying outcome measures and inclusion criteria. Fibula fixation was associated with less rotational malalignment, while there does not seem to be consensus regarding the effect on sagittal and coronal alignment. Six studies reported on the effect of fibula fixation on tibial union. None of these studies found a significant difference between treatment modalities. Furthermore, one out of three studies reporting functional outcome described a marginal beneficial functional outcome after fibula fixation. Ultimately, no differences in complication rates between treatment modalities were described. CONCLUSION: Fixation of the fibula in distal-third lower leg fractures does not seem to have a significant effect on coronal and sagittal tibial alignment. Furthermore, fibula fixation is associated with significantly less rotational malalignment, although the clinical importance of this finding is questionable as true differences in rotational alignment between treatment modalities are small. Finally, fibula fixation does not affect union, functional outcome, or complication rate as adjuvant to tibia fixation. LEVEL OF EVIDENCE: II.
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Fraturas do Tornozelo , Fraturas da Fíbula , Fixação Intramedular de Fraturas , Fraturas da Tíbia , Humanos , Tíbia/cirurgia , Fíbula/cirurgia , Fixação Interna de Fraturas , Estudos Retrospectivos , Fraturas da Tíbia/cirurgia , Fraturas da Tíbia/complicações , Fraturas do Tornozelo/complicações , Resultado do TratamentoRESUMO
INTRODUCTION: Fractures of the distal femur with metaphyseal comminution and complete intra-articular involvement (AO/OTA classifications 33C2 and 33C3) present challenges for reduction and fixation. However, an optimal fixation method remains unknown. This study aimed to compare the clinical and radiographic outcomes of locking extramedullary plating (LEP) and retrograde intramedullary nailing (RIN) for complete distal femoral intra-articular fractures with metaphyseal comminution. MATERIALS AND METHODS: Between January 2016 and May 2022, 80 patients (45 men and 35 women; average age, 56.7 years) diagnosed with AO/OTA 33C2 and 33C3 were treated with either LEP or RIN and followed up for at least one year. Post-operative evaluations included radiographic assessments of bone union rate, timing, and alignment. Clinically, the knee joint range of motion (ROM), lower extremity functional scale (LEFS), and Kellgren and Lawrence (KL) grade were analyzed. The complications were also compared. RESULTS: 36 underwent LEP and 44 underwent RIN. Bone union was observed in 69.4% and 63.6% of the patients in the LEP and RIN groups, respectively (p = 0.64). The average union time was 6.9 months for the LEP group and 6.6 months for the RIN group (p = 0.51). A tendency toward varus deformity was observed in the RIN group, although the difference was not statistically significant. No significant differences were observed in knee ROM, LEFS, or KL grade. Complications included non-union (33.8%; RIN, 11; LEP, 16), varus deformity (5%; RIN, 4; LEP, 0), infection (1.3%; RIN, 0; LEP, 1), heterotrophic ossification (1.3%; RIN, 0; LEP, 1), and wound dehiscence (2.5%; RIN, 2; LEP, 0). CONCLUSIONS: The surgical fixation methods, RIN and LEP, for complete distal femoral intra-articular fractures with metaphyseal comminution showed similar clinical and radiological outcomes. However, regardless of the type of fixation device used, there was a reduced rate of bone union owing to high energy and a less favorable prognosis.
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Placas Ósseas , Fraturas do Fêmur , Fixação Intramedular de Fraturas , Fraturas Cominutivas , Humanos , Pessoa de Meia-Idade , Feminino , Masculino , Fixação Intramedular de Fraturas/métodos , Fixação Intramedular de Fraturas/instrumentação , Fraturas do Fêmur/cirurgia , Fraturas do Fêmur/diagnóstico por imagem , Idoso , Fraturas Cominutivas/cirurgia , Fraturas Cominutivas/diagnóstico por imagem , Adulto , Estudos Retrospectivos , Fraturas Intra-Articulares/cirurgia , Fraturas Intra-Articulares/diagnóstico por imagem , Amplitude de Movimento ArticularRESUMO
INTRODUCTION: Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. MATERIALS AND METHODS: Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking. RESULTS: For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01. CONCLUSIONS: From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.
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Placas Ósseas , Fios Ortopédicos , Fixação Interna de Fraturas , Fraturas Ósseas , Patela , Humanos , Patela/lesões , Patela/cirurgia , Fenômenos Biomecânicos , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/instrumentação , Fraturas Ósseas/cirurgia , Cadáver , Idoso , Masculino , Feminino , Fratura da PatelaRESUMO
PURPOSE: To methodically assess the effectiveness of augmentative plating (AP) and exchange nailing (EN) in managing nonunion following intramedullary nailing for long bone fractures of the lower extremity. METHODS: PubMed, EMBASE, Web of Science, and the Cochrane Library were searched to gather clinical studies regarding the use of AP and EN techniques in the treatment of nonunion following intramedullary nailing of lower extremity long bones. The search was conducted up until May 2023. The original studies underwent an independent assessment of their quality, a process conducted utilizing the Newcastle-Ottawa scale. Data were retrieved from these studies, and meta-analysis was executed utilizing Review Manager 5.3. RESULTS: This meta-analysis included 8 studies involving 661 participants, with 305 in the AP group and 356 in the EN group. The results of the meta-analysis demonstrated that the AP group exhibited a higher rate of union (odds ratio: 8.61, 95% confidence intervals (CI): 4.12 - 17.99, p < 0.001), shorter union time (standardized mean difference (SMD): -1.08, 95 % CI: -1.79 - -0.37, p = 0.003), reduced duration of the surgical procedure (SMD: -0.56, 95 % CI: -0.93 - -0.19, p = 0.003), less bleeding (SMD: -1.5, 95 % CI: -2.81 - -0.18), p = 0.03), and a lower incidence of complications (relative risk: -0.17, 95 % CI: -0.27 - -0.06, p = 0.001). In the subgroup analysis, the time for union in the AP group in nonisthmal and isthmal nonunion of lower extremity long bones was shorter compared to the EN group (nonisthmal SMD: -1.94, 95 % CI: -3.28 - -0.61, p < 0.001; isthmal SMD: -1.08, 95 % CI: -1.64 - -0.52, p = 0.002). CONCLUSION: In the treatment of nonunion in diaphyseal fractures of the long bones in the lower extremity, the AP approach is superior to EN, both intraoperatively (with reduced duration of the surgical procedure and diminished blood loss) and postoperatively (with an elevated union rate, shorter union time, and lower incidence of complications). Specifically, in the management of nonunion of lower extremity long bones with non-isthmal and isthmal intramedullary nails, AP demonstrated shorter union time in comparison to EN.