Fracture Characteristics Research Articles

Study on Characteristics of Ultrasound-Assisted Fracture Splitting for AISI 1045 Quenched and Tempered Steel.

Ultrasonic vibration-assisted con-rod fracture splitting (UV-CFS) was used to carry out the fracture experiment of 1045 quenched and tempered steel. The effect of ultrasonic vibration on the fracture properties was studied, the fracture microstructure and the evolution of dislocations near the fracture were analyzed and the microscopic mechanism was analyzed. The results show that in the case of conventional fracture splitting without amplitude, the dimple and the fracture belong to ductile fracture. With the increase in ultrasonic amplitude, the plasticity and pore deformation of the con-rod samples decrease at first and then increase; when the amplitude reaches a certain point, the load required for cracking is reduced to a minimum and the ultrasonic hardening effect is dominant, resulting in a decrease in the plasticity of the sample, a cleavage fracture, a brittle fracture, the minimum pore deformation and high cracking quality. The research results also show that with the increase in ultrasonic amplitude, the fracture dislocation density decreases at first, then increases, and dislocation entanglement and grain breakage appear, then decrease, and multiple dislocation slip trajectories appear. The changes in the dislocation density and microstructure are consistent with the above results.

Low reoperation rate after fixation of displaced femoral neck fractures with the femoral neck system (FNS).

Operative fixation of femoral neck fractures (FNFs) remains challenging. Complications are not infrequent, especially in displaced patterns. Numerous fixation techniques have been previously described in the literature; however, there remains a paucity of data regarding outcomes of these injuries treated with the femoral neck system (FNS). Patients with a displaced FNF (OTA/AO 31B) treated with the FNS at a single level 1 academic trauma center between 1/1/2019 and 1/1/2023 were identified. Radiographs were reviewed to assess fracture displacement, location, and characteristics. Patient records were further reviewed to assess for complications, reoperations, and osseous union. Forty-three patients (65% male) with 44 FNFs were identified with a mean age of 35.0years (range, 13-61years). Two patients developed a deep infection requiring surgical debridement, four patients underwent a total hip arthroplasty, and one patient underwent a valgus intertrochanteric osteotomy for nonunion. There were three cases of femoral head AVN. Mean follow-up was 482.5days among all patients, and 36 fractures had at least 6months of follow-up or reached bony union. Here, we present a series of patients treated with the FNS for internal fixation and report a 18% reoperation rate. This is lower than the average rate that has been previously reported in similar patient populations in the literature treated with alternative methods of internal fixation. Thus, the FNS appears to be a safe and effective option for treatment of these injuries.

Straw movement and flow field in a crushing device based on CFD-DEM coupling with flexible hollow straw model

To accurately predict and evaluate the performance of the crushing device of no-till planter, it is strongly necessary to establish an accurate interaction model of the straw-crushing device coupling system. The traditional model has low prediction accuracy and cannot simulate the fracture characteristics of the straw during the operation of the crushing device due to the straw being usually regarded as a rigid body or a combination of rigid ball joints. In this paper, a breakable and flexible hollow straw model is first proposed and a CFD-DEM coupling model of the straw group-crushing device considering the effect of gas-solid two phase is also established. Afterwards, the corresponding verification experiments are conducted and the effect of working and structural parameters on the straw-throwing weight and crushing length is also analysed. It is demonstrated that the relative error between the simulation results and the experimental results for the straw crushing length is 7.7%, and the relative error for the straw-throwing weight is 7.1%, thereby verifying the correctness of the CFD-DEM model. Finally, the response surface method is also used to determine the optimal working and structural parameters of the crushing device and corresponding field tests verification is also conducted. Results indicate that the optimal parameter combination is as: the rotational speed of the crushing spindle is 2400 rpm, the inlet clearance is 30 mm and the starting point angle is 45°. Moreover, the crushing length after optimisation is 6.6% smaller than before optimisation, and the straw-throwing weight is increased by 11.5%.

Damage evolution of tunnel lining under creep action considering interlayer effect in gently inclined layered surrounding rock

The anisotropy and creep characteristics of layered sandstone mudstone with different structural inclinations have a significant impact on the safety of tunnel construction and operation. we conducted research of the layered sand-mudstone of the Yunding Tunnel on the Dazhou-Chengdu line, based on the mechanical response mechanism of layered surrounding rock and employing a numerical coupling analysis method, established a creep damage mechanical model of layered rock to study the progressive failure characteristics of layered rock and the failure mechanism of tunnel lining. The results indicate that:(1) The response mechanism of layered rock mechanics based on the delamination effect can well reflect the progressive fracture of the layered rock and distinguish the failure mode of layered rock; (2) The established layered rock mechanics contact model can effectively characterize the anisotropic macroscopic mechanical properties of layered sand-mudstone in biaxial test and triaxial creep test; (3) The fracture characteristics of the layered surrounding rock matrix change significantly with the change of the dip angle of the structural plane, the cracks mainly appear in the direction perpendicular to the structural plane. And it can be determined that the critical angle of sliding failure of layered sand mudstone is α1 = 28.77°, α2 = 65.47° (4) The damage evolution of lining can be divided into four states: 1. elastic state 2. injury working state 3. ultimate bearing state 4. damage state. With the increase of the dip angle of the structural plane, the time for the lining to enter the ultimate bearing state is gradually delayed, and the delayed rate shows the characteristics of ’slower-faster-slower’. This research achievement can provide a certain foundation for the analysis of the failure mode and the failure mechanism of tunnel lining.

Microstructure and properties nonuniformity of Ti6Al4V component fabricated by high-power laser melting deposition

High-power laser melting deposition provides an efficient solution for the fabrication of large-sized titanium alloy components. In this study, Ti6Al4V blocks with well-formed structures were prepared using a 7 kW laser power, and their internal defect distribution, microstructure along the deposition direction, tensile properties, and fatigue performance were investigated. The results showed that the density of the as-deposited Ti6Al4V blocks could reach 99.94%, and the main internal defects were cavities, primarily spherical and dispersed, with a maximum diameter of 326.7 μm. Among them, 65.53% of cavities had a diameter smaller than 100 μm, and 92.76% had a diameter smaller than 200 μm. The microstructure at the top region of the specimen consisted of a needle-shaped α phase, the middle region had a mixture of needle-shaped and lamellar α-phase, and the bottom region showed a lamellar α-phase structure. With an increase in deposition height, the aspect ratio of α-phase increased, and the average width decreased from 3.22 μm to 0.88 μm. The internal structure was mainly composed of a basket-weave structure, with a small amount of Widmanstätten structure present at grain boundaries. Hardness and tensile properties exhibited significant non-uniformity along the deposition height. The tensile strength and yield strength at the top region were approximately 50 MPa higher than those in the middle and bottom regions, while the elongation was about 2% lower. The top region's tensile fracture surface displayed a sawtooth pattern, whereas the middle and bottom regions exhibited fractures along the 45° direction of the principal stress. The length of α-bundles and the interface density within the bundles were crucial factors affecting crack propagation. In the top region, α bundles were the longest, and the interface density was the highest. During crack propagation, when the crack extended perpendicular to the α bundles, it encountered high resistance, and when it extended non-perpendicular, it rapidly propagated along the bundle boundaries, exhibiting high strength and low plasticity. The fatigue performance of the Ti6Al4V specimens fabricated by high-power laser melting deposition showed significant dispersion, with cracks originating from subsurface lack of fusion defects. At different stages of fatigue crack propagation, the role of α phase laths varied: during the fatigue source region, cracks primarily propagated along the boundaries of α laths, displaying significant cleavage fracture characteristics. In the fatigue propagation region, crack propagation velocity was mainly influenced by the direction of the laths, and in the fatigue final rupture region, ductile fracture was predominant. Α laths parallel to the tensile direction exhibited the best plasticity, promoting the formation of large dimples and high tear ridges.

Strength Evolution and Fracture Feature of Carbon Fiber-Reinforced Silica Sol Shell for Investment Casting

Strength Evolution and Fracture Feature of Carbon Fiber-Reinforced Silica Sol Shell for Investment Casting

Sliding wear study of the Inconel-625 clad deposits by microwave heating on SS-304

In this present study, the Inconel-625 powder was used for the surface modification of SS-304 alloy by utilizing the concept of a hybrid microwave heating technique. The XRD analysis shows the presence of various carbide and Laves phases in addition to a Ni-Cr-Fe-based face-centred-cubic matrix in the modified clad layer. The microstructural analysis revealed that the developed clad was metallurgically bonded with the substrate and free from any interfacial cracks. The modified layer mainly consists of two regions: cellular (matrix) regions and grain boundaries (GBs) regions. The average porosity in the modified clad layer was evaluated to be about 1.65%. The average microhardness (440 ± 45 HV) of the modified clad layer was observed to be about 2.1 times the base metal microhardness (210 ± 10 HV). The clad specimens exhibited a considerably lower wear rate (about 2.8 times less weight loss) than the substrate SS-304 during the dry sliding wear test. The shallow grooves, craters, and material debonding were the typical fracture features associated with the clad surfaces during rubbing when examined under a scanning electron machine apparatus.

Radiographic and functional results of Ilizarov fixation in the management of nonunion of tibia and femur fractures: a retrospective case series.

Femoral and tibial fractures may result in delayed union and nonunion, posing significant challenges in orthopedic practice. The Ilizarov technique has emerged as a promising solution for managing these complex cases. Evaluate the radiographic and functional results of Ilizarov fixation in the treatment of nonunion of tibia and femur fractures. Retrospective. Hospitals affiliated with a university hospital. Patient demographics, fracture characteristics, and treatment details were analyzed for the period from October 2015 to September 2022 in patients who were treated for nonunion of the tibia and femur using the Ilizarov fixator. Clinical and radiological assessments were performed using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria. The study focused on assessing the average duration for union and frame removal, bone results, successful union rates, and functional results using the ASAMI criteria, obtaining data from the existing medical records, spanning various medical facilities treating nonunion fractures. 126 patients. The average duration for union and frame removal was 8 months, with excellent bone results observed in 60.32% of cases. Out of 126 patients, 118 achieved successful union, while there were 2 failure cases necessitating amputation (1.52%). Functional results revealed excellent outcomes in 39.68% of cases. Complications included pin tract infections, ankle and knee stiffness, and limb shortening. External fixation duration and infection eradication were consistent with previous research, emphasizing the technique's effectiveness. The Ilizarov technique proved highly effective in managing nonunion tibia and femur fractures, offering favorable outcomes in terms of union, infection control, pain relief, and functional recovery. While excellent bone outcomes do not guarantee optimal function, this method remains a reliable approach for complex cases. Potential biases inherent in retrospective analyses and the need for further randomized controlled trials to comprehensively compare treatment modalities.

Experimental study on the deterioration of mechanical properties of sandy mudstone under different water-gas interactions

Based on the water-rock-gas coupling test system, the work combined the scanning electron microscope and XTDIC 3D full-field strain measurement system. The Brazilian splitting test was performed on four groups of sandy mudstone specimens under contrast (CO), mash-gas soaking (MS), water-mash gas soaking (WM), and water-soaking (WS) conditions. The tensile strength, deformation failure, and microscopic characteristics of fractures were studied to reveal the deterioration mechanism of the tensile properties of sandy mudstone under water-gas coupling. The results showed that the uniaxial tensile strength of sandy mudstone specimens under the three soaking conditions was less than that of the contrast conditions. Compared with specimens in the CO group, the tensile strength of specimens in MS-WS groups was reduced; the WS group decreased the most. Specimens changed from brittle failure to plastic failure after soaking. The decrease rate in strength after the peak was consistent with the change trend in tensile strength. It led to a larger localized deformation zone of specimens and more obvious displacement. The deformation localization zone of the WS group was the broadest, with the most intense displacement. Besides, stress concentration first occurred in the submerged part of the WM group. Fractures expanded in the direction of maximum principal strain. The internal pore structure of sandy mudstone specimens in each group changed after soaking. The average porosity, maximum pore area, and probability entropy of specimens in WS-MS groups increased compared to the CO group. The WS group had the largest reduction and the MS group had the smallest. The pre-peak energy storage capacity of sandy mudstone specimens was gradually weakened. Compared with the CO group, that in the WS-MS groups was reduced. The WS group had the greatest reduction, and the MS group had the smallest. The deterioration effect of water on the interior of sandy mudstone was stronger than that of gas. The work is of great significance for understanding the stability of coal and rocks in closed-pit high-gas mines.

Influencing mechanism of nanoscale He bubbles on the crack propagation in TiT1.75 under tension

This work investigates the influence of the pre-existing He bubble on the crack propagation in TiT1.75 with molecular dynamic simulations. Under high strain rate tension, TiT1.75 exhibits typical brittle fracture characteristics with low fracture toughness at the microscopic scale, and the crack propagation path approximately follows the (111) plane with normal stretching direction. However, the presence of He bubble may change the stress concentration near the crack tip, resulting in the bending and even branching of cracks. The position relationship between He bubbles and crack tips is discussed, and the variation of the tensile strength with the distance and the angle is revealed. The total length and pattern of crack propagation are also presented. It is found that the tensile strength approximately linearly decreases with the He bubble concentrations, and the self-expansion and coalescence of He bubbles will gradually dominate the fracture process.

Factors contributing to non-union amongst dentate mandibular fractures treated by load-sharing miniplate osteosynthesis: a case-control study

The stability provided by load-sharing miniplate osteosynthesis (LSMO) in dentate mandibular fractures (DMF) is usually adequate for bony healing. Non-union following LSMO is an uncommon complication. We aimed to determine the incidence and identify contributing factors, if any, of non-union amongst DMFs that have undergone LSMO. This retrospective case-control study with an allocation ratio of 1:3 includes cases of non-union DMF following LSMO and controls with healed DMF following LSMO over a five-year period. Relevant sociodemographic data, mandibular fracture characteristics, and treatment variables were collected for both groups. Of the 381 patients who underwent LSMO for DMFs, 12 cases of non-union were identified. The control group included 36 patients with uncomplicated healing. A significant association was observed between non-union and teeth in the line of fracture, postoperative infections, and time from injury to LSMO. The odds ratio with chronic alcohol usage was 1.4. Vigilant follow up of patients with chronic alcohol use, those with teeth in the fracture line, and adherence to LSMO principles may help to minimise the non-union complication.

A6N01S-T5 physical characterization of laser-MIG hybrid welding of aluminum alloys

A 3 mm thick A6N01S-T5 aluminum alloy profile typical joint structure is used to carry out a laser-MIG hybrid welding test. The hybrid welding process parameters are optimized. The laser-MIG hybrid welding engineering adaptability is studied. The results show that the weld is well-formed and free of porosity defects under the optimum process parameters. The center of the weld is a dendritic cast organization. The region near the fusion line weld is a columnar crystal organization. The fusion zone is narrow, but there is a slight coarsening of the grain in the heat-affected zone. The hardness of the weld zone is lower than that of the parent material. The minimum hardness is located in the heat-affected zone near the fusion line. The average tensile strength of the joint under the best process parameters is 204.6 MPa, reaching 83.5% of the parent material. The fracture occurred near the fusion line, and the fracture shape showed typical plastic fracture characteristics. The bending performance of the joint was good. The optimal process parameters were universal when the pair gap was less than 1.0 mm, and the weld formation and tensile strength of the joint were good. When the pair gap increased to 1.5 mm, the optimized process parameters of the weld formation and tensile strength of the joint were still good. The results show that laser-MIG hybrid welding has good welding feasibility and engineering adaptability for typical joints in aluminum alloy bodies of high-speed trains.

Anisotropic characteristics and creep model for thin-layered rock under true triaxial compression

The failure phenomenon of thin-layered rock tunnels not only exhibits asymmetric spatial characteristics, but also significant time-dependent characteristics under high in-situ stress, which is attributed to the time-dependent fracture of thin-layered rocks. This paper conducted a series of true triaxial creep compression tests on typical thin-layered rock siliceous slate with acoustic emission technique to reveal its anisotropic time-dependent fracture characteristics. The anisotropic long-term strength, creep fracturing process, and fracture orientation characteristics of thin-layered rocks under different loading angles (β, ω) and intermediate principal stress were summarized. A three-dimensional (3D) non-linear visco-plastic creep model for thin-layered rock was developed to simulate its anisotropic creep behavior. The time-dependent fracturing of rocks during true triaxial creep loading is reflected through the change of equivalent strain based on an improved Euler iteration method. By constructing the plastic potential function and overstress index related to loading angles and stress state, the anisotropic time-dependent fracturing process and propagation of thin-layered rocks under different loading angles and intermediate principal stress are expounded. The model was validated experimentally to show it can reflect the long-term strength and creep deformation characteristics of thin-layered rocks under true triaxial compression.

Microstructure evolution under different austenitizing temperatures and its effect on mechanical properties and mechanisms in a newly high aluminum bearing steel

A new type of lightweight high aluminum bearing steel had been developed based on the widely used high carbon chromium bearing steel. Via multi-scale experimental characterizations and theoretical calculations, here we mainly focused on the evolution of microstructure including precipitates under different quenching temperatures. Accordingly, the mechanical properties, mechanisms and fracture features of the new high-Al steel after tempering were characterized in detail. As austenitizing temperature rose, matrix of steel varied from multiphase structure of martensite, retained austenite (RA) and ferrite to the full martensite and RA. RA was found in all four samples with the austenitizing temperature from 850 °C to 1000 °C. In terms of precipitates, a transformation from M3C to M7C3 were observed. As a phase newly introduced by Al, AlFe3C (κ carbides) would dissolve into matrix at 900 °C. Eventually, the yield strength of the researched steel could reach 1430 MPa with an unnotched impact energy of 35 J. Theoretical results showed that high strength of researched steel was mainly caused by solid solution effect of carbon and high density of dislocation. In terms of toughness and fracture observation, high impact energy was attributed to the highest density of grain boundary, and also, κ carbides were found at the origin of secondary crack. This study highlighted the significant effect of Al addition and quenching process based on the traditional bearing steel, which showed a novel method and idea to reduce significantly the weight of bearings.

Characteristics of Nonunion Fractures in Patients with Antebrachial Fractures at dr. Mohamad Soewandhie General Hospital Surabaya 2021-2022: A Retrospective Study

Background: Nonunion, a complication of fracture healing, can lead to patient morbidity. Contributing factors include age, gender, fracture type, multiple fractures, infection, prolonged nonsteroidal anti-inflammatory drug (NSAID) use, smoking, nutritional status, and history of chronic disease. This study aims to determine the prevalence and characteristics of nonunion antebrachial fractures at dr. Mohamad Soewandhie General Hospital Surabaya. Methods: This retrospective descriptive study involved 111 patients. Data was gathered from medical records treated at dr. Mohamad Soewandhie General Hospital Surabaya for antebrachial fracture during 2021-2022. The study protocol obtained approvals from two local ethical committees. Data included demographics, fracture characteristics, fracture type, multiple fractures, infection, NSAID use, hypertension and diabetes history, smoking habits, and nutritional status by BMI calculation. Results: This study found a 24.3% prevalence of antebrachial nonunion fractures at dr. Mohamad Soewandhie General Hospital Surabaya in 2021-2022, mostly in males (66.7%) aged 17-25 years (22.2%). Nonunion in antebrachial fractures is marked by high rates in closed (92.6%) and single fractures (92.6%). Notably, infections (22.2%), smoking (7.4%), and hypertension history (7.4%) are common contributors. Despite ideal BMI in many cases (44.4%), nonunion still occurred. Conclusions: The study conducted at Dr. Mohamad Soewandhie General Hospital in Surabaya revealed a high prevalence of antebrachial nonunion fractures at 24.3%, particularly among young males. It was found that closed, single fractures were the most common type, with infections, smoking, and a history of hypertension being significant contributing factors. Interestingly, even individuals with an ideal BMI were still at risk for nonunion.

Effect of fan-shaped structure on high temperature tensile properties of nickel-based deformed superalloys

GH4742 alloy is a kind of precipitation-hardened superalloy, which is widely used in turbine disc, compressor disc, bearing ring and other parts due to its excellent high temperature mechanical properties. In this paper, high-temperature tensile comparison experiments were carried out at four temperatures, 1050 °C, 1080 °C, 1110 °C and 1140 °C, between alloy A containing a fan-shaped structure and alloy B without a fan-shaped structure. The results show that the tensile strength and plasticity of alloy A at 1050 °C are superior to those of alloy B. With the increase of temperature, the difference of tensile strength and plasticity between alloy A and B decreases gradually. By analyzing the fracture, both alloy A and B were found to have a large number of tough dimples, which showed ductile fracture characteristics. But alloy B was found to have some icing-like fracture at 1050 °C, which showed some brittle fracture characteristics. After 1110 °C, the difference in tensile strength and plasticity between alloy A and B almost disappears because γ′ phase is completely dissolved in the matrix. TEM results show that dislocations gather around the large-size γ′ phase, and for the small-size γ′ phase, dislocations tend to cut into γ′ phase directly. The results show that the existence of fan-shaped structure is beneficial to the high temperature tensile properties of GH4742 alloy, which has a certain reference effect on the production of GH4742 alloy in the future.

Laser Transmission Welding of Polypropylene: Insights into Parameter Interplay, Thermal Analysis, Bonding Quality, Fracture Characteristics, and Weld Morphology

Laser Transmission Welding of Polypropylene: Insights into Parameter Interplay, Thermal Analysis, Bonding Quality, Fracture Characteristics, and Weld Morphology

Clinical characteristics and associated features of pure orbital roof fractures: A ten-year retrospective review

PurposeTo present the demographics and clinical characteristics of pure (rim-sparing) orbital roof fractures. MethodsThis retrospective observational study used 10 years of data from a single institution. Patient age, sex, laterality, field of binocular single vision, associated injuries, and radiologic features were analyzed. Orbital roof fractures were categorized into four groups: comminuted/open, hinged, trapdoor, and linear. These were further subdivided into blow-in (-down) and blow-out (-up) fractures. Injury etiology was classified into fall, traffic accidents, sports injuries, assault, work-related, and others. ResultsData documented a low incidence rate of 2.5% (27 patients) in 1074 patients. Most patients were male (81%). The most common cause of injury was fall (48%), followed by traffic accidents (22%). Comminuted/open fractures constituted the bulk of fracture types (54%), followed by hinged, and linear fractures. Blow-in and blow-out fractures had an incidence rate of 50% each. Concomitant fractures of the medial and inferior orbital walls were predominant. Low surgical intervention was noted owing to acceptable field of binocular single vision outcomes, and the field of binocular single vision included the primary position of gaze in 88% of patients. ConclusionPure orbital roof fractures occurred in 2.5% of patients with pure orbital fractures. Patients were predominantly male with trauma caused by high energy forces, which regularly caused comminution of the roof and fractures of the medial and inferior orbital walls. Most patients were managed conservatively.

Improving laser welded joint performance of medium-Mn steel through C and Mn partition by intercritical annealing process

In this paper, the fracture failure mechanism of laser welded (LW) joints of medium-Mn steel is studied. And the mechanical properties of the joints were greatly improved by designated intercritical annealing (IA) process. Experimental results showed that the elongation of the as-welded joint of medium-Mn steel is very low, and the fracture shows typical brittle fracture characteristics. Electron probe micro-analyzer (EPMA) test showed that there were many Mn segregation bands in the joint, and electron backscatter diffraction (EBSD) surface scanning test further demonstrated that many Mn23C6 carbides were produced at the martensite grain boundary (GB) of the fusion zone (FZ), which was the main reason for the occurrence of brittle fracture in the FZ. The IA process improves the segregation of Mn element at the GB of the joint and reduces the intergranular brittleness. At the same time, more austenite was distributed by C and Mn elements, and more Fe3C phases were found near austenite in the EBSD diagram, which provided nucleation centers for the formation of austenite. The product of strength and elongation (PSE) of the IA treated joint was dramatically increased by 2693.65%.

Periprosthetic Hip Fractures around the Stem: Can the Stem Design Affect Fracture Features?

Background: Total hip arthroplasty is one of the most successful orthopedic surgeries; nevertheless, many of these surgeries are the causes of failure, and among them, periprosthetic fractures are one of the major causes of revision. Our study focuses on periprosthetic hip fractures with two different stem designs. The aim of the study was to analyze the obtained results, focusing on the features of periprosthetic stem fractures observed. Methods: We retrospectively reviewed periprosthetic fractures occurring between 2010 and 2023, involving Alloclassic® or CLS® uncemented femoral stems. We analyzed demographic data, proximal femur morphology, and the fracture type. Results: We identified 97 patients. Considering the proximal femur morphology, we found that there was statistically significant prevalence of Dorr A proximal femur morphology in the CLS® group and of Dorr C in the Alloclassic® group. Considering the distribution of the fracture pattern, we reported a non-statistically significant prevalence of the fracture pattern with stable stems in the CLS® group. Conclusions: The choice of the prosthetic design of the femoral stem is a crucial element when planning total hip arthroplasty. However, we found a non-statistically significant difference between the two stems considered, raising questions about the real role of stem design as a primary determinant of periprosthetic hip fractures.