Abstract
Objective:
Femoral reconstruction nails (RN) and three cannulated screws combined with a plate (TCP) are commonly employed for the treatment of ipsilateral femoral neck and shaft fractures (IFNSF). However, these fixation strategies are associated with a considerable incidence of postoperative complications, reflecting the biomechanical challenges of this fracture pattern. Therefore, this study aims to compare the biomechanical performance of a novel long proximal femoral bionic nail (PFBN) with these conventional fixation methods for the treatment of this complex fracture pattern.
Methods:
Computed tomography (CT) data of the femur were obtained from a healthy adult male volunteer to reconstruct a three-dimensional femoral model using Mimics 21.0 and Geomagic Studio 2013. A combined femoral shaft and ipsilateral femoral neck fracture model was then established in UG 12.0. Three internal fixation constructs—the long PFBN, RN, and TCP—were designed and assembled to simulate surgical fixation. Finite element analysis was subsequently performed using Abaqus 2022 to evaluate stress distribution and displacement characteristics among the three fixation constructs.
Results:
Under the three loading conditions, the long PFBN exhibited lower or comparable stress and displacement within the fixation constructs. Compared with the TCP construct, the long PFBN showed a more uniform stress distribution. In most loading scenarios, its mechanical performance was comparable to, or slightly better than, that of the RN construct. Analysis of fracture-site micromotion indicated that tangential micromotion at the femoral neck fracture interface in the long PFBN construct was intermediate between that of the RN and TCP constructs.
Conclusion:
In this finite element analysis, the long PFBN demonstrated relatively favorable biomechanical performance under axial, bending, and torsional loading conditions. These findings may provide preliminary biomechanical insights into the comparative performance of different fixation strategies for this complex fracture pattern.
Introduction
With the rapid development of transportation and construction industries, the incidence of ipsilateral femoral neck and shaft fractures (IFNSF) has increased in recent years, accounting for approximately 1%–9% of femoral shaft fractures (Mohan et al., 2019). The management of this complex injury remains challenging, with substantial variability in clinical outcomes. The overall complication rate is higher than that observed in isolated femoral shaft or femoral neck fractures. Reported complications include coxa vara (up to 28%) (Tsai et al., 2009), infection (up to 10%) (Du et al., 2016), malunion (up to 7%) (Tsai et al., 2009), nonunion (5%–9% for femoral shaft and 1%–2% for femoral neck) (Tsai et al., 2009; Ostrum et al., 2014), avascular necrosis of the femoral head (up to 4%) (Tsai et al., 2009), and internal fixation failure.
Currently, the clinical management of this fracture type primarily relies on two strategies: femoral reconstruction nails (RN) and cannulated screws combined with a plate (TCP) (Singh et al., 2008). Each approach offers distinct advantages. The RN provides intramedullary central fixation, with a load-bearing axis closer to the mechanical axis of the lower limb, which may facilitate more uniform stress transmission and reduce disruption to the blood supply at the fracture site. In addition, both fractures can be addressed simultaneously using a single implant (Zhao et al., 2023; Dahuja et al., 2018). In contrast, the TCP strategy enables separate and relatively rigid fixation of the femoral neck and shaft, thereby providing more direct local control. However, clinical observations and previous studies suggest that both strategies are associated with certain biomechanical limitations. For proximal femoral fractures, both RN and TCP typically adopt parallel screw configurations, which have been associated with complications such as screw loosening, cut-out, loss of the neck–shaft angle, and avascular necrosis of the femoral head under complex loading conditions (Gadegone et al., 2017; Samsami et al., 2019; Bojan et al., 2018). For femoral shaft fractures, these fixation methods involve intramedullary central fixation (RN) and extramedullary eccentric fixation (TCP), respectively. In the TCP system, the screws and plate are not integrated into a single construct, which may lead to discontinuous load transfer. This may contribute to stress shielding at the fracture interface and potentially affect the bone healing process (Baghel et al., 2021; Angelini et al., 2021).
The occurrence of these complications is likely multifactorial; however, the mismatch between internal fixation devices and the anatomical and biomechanical environment of the femur may represent an important contributing factor. To improve internal fixation strategies for proximal femoral fractures, the research team led by Academician Yingze Zhang investigated the trabecular architecture of the proximal femur and proposed the concept of triangular-supported fixation (TSF). This concept involves constructing a stable triangular support structure to restore the physiological load distribution of tensile and compressive trabeculae in the proximal femur. Such a design may enhance fixation strength and improve rotational stability (Zhu et al., 2021; Zhang Kaixuan et al., 2024). Based on this concept, the proximal femoral bionic nail (PFBN) was developed. Previous finite element analyses and preliminary clinical studies suggest that PFBN exhibits favorable biomechanical performance in proximal femoral fractures, such as intertrochanteric fractures (Zhang Yi-Fan et al., 2024; Ding et al., 2023). However, the application of this concept and the long PFBN in the treatment of femoral shaft fractures combined with ipsilateral femoral neck fractures remains insufficiently investigated from a biomechanical perspective.
Therefore, this study aimed to compare the biomechanical performance of a long proximal femoral bionic nail (PFBN), based on the triangular-supported fixation concept, with two conventional internal fixation methods—femoral reconstruction nail (RN) and cannulated screws combined with a plate (TCP)—using a finite element model of IFNSF. Stress distribution, displacement patterns, and fracture-site micromotion were analyzed to evaluate the biomechanical performance of the long PFBN for this complex fracture pattern.
Materials and methods
General information
A healthy adult male volunteer (body weight: 73 kg) with no history of fractures, tumors, or limb trauma was included in this study. The study protocol was approved by the Medical Ethics Committee of the Third Hospital of Hebei Medical University (Approval No. Ke2021-059-1). The requirement for written informed consent was waived.
Image data acquisition
A 64-slice spiral computed tomography (CT) scanner was used to acquire images of the lower limb of the volunteer. The scanning range extended from the hip joint to the knee joint to ensure complete femoral CT data acquisition. All images were stored in Digital Imaging and Communications in Medicine (DICOM) format for subsequent analysis.
Femur model reconstruction
The DICOM files were imported into Mimics 21.0 software (Materialise, Belgium) for three-dimensional reconstruction. Based on the CT attenuation values of different tissues, grayscale threshold values were defined to segment the initial femoral structure. Region growing, mask editing, and smoothing procedures were applied to generate a geometric model of the femur, which was subsequently exported in STL format. The femoral geometry was then imported into Geomagic Studio 2013 (Geomagic, USA), where noise reduction, surface smoothing, feature removal, contour editing, mesh generation, and surface fitting were performed to reconstruct a solid femoral model. Subsequently, separate models of cortical and cancellous bone were established.
Fracture and fixation model establishment
The geometries of the internal fixation devices were designed in UG 12.0 (Siemens PLM Software, Germany) according to manufacturer specifications. The intramedullary nails had a length of 380 mm, a diameter of 11 mm, and a neck–shaft angle of 125°. The distal locking screws had a diameter of 5 mm. For the PFBN, the proximal fixation screw and support screw had diameters of 7.5 mm and 5.5 mm, respectively. For the RN, the proximal screws had a diameter of 6.5 mm. The plate used in the TCP system had a length of 330 mm and a thickness of 5 mm, while the cannulated screws had a diameter of 6.5 mm and a length of 95 mm. Based on previous studies (Alborno et al., 2023; Wolinsky and Johnson, 1995; Alho, 1996), an unstable Pauwels type III femoral neck fracture was created at the base of the femoral neck. Additionally, approximately 2 mm of bone was removed from the midshaft to simulate a comminuted femoral shaft fracture (Shengyuan, 2022). The fracture models were then assembled with the corresponding fixation devices according to standard orthopedic surgical principles by an experienced orthopedic surgeon. To reduce computational cost, screw threads were simplified as smooth cylindrical surfaces. The assembled models were exported in STP format for subsequent analysis (Figure 1).
FIGURE 1
The complete femoral and fixation models were imported into HyperMesh 13.0 software (Altair, USA) for mesh generation. Both bone and implant models were meshed using C3D4 tetrahedral elements. Mesh convergence analysis demonstrated that the variation in key outcome parameters was less than 5%, indicating adequate mesh convergence. The mesh size of both cortical and cancellous bone was set to 1.5 mm. The femoral model consisted of 125,789 nodes and 496,822 elements. The numbers of nodes and elements for the three models are summarized in Table 1.
TABLE 1
| Components | Nodes | Elements |
|---|---|---|
| Long PFBN | 187962 | 764162 |
| RN | 188656 | 769867 |
| TCP | 195506 | 779283 |
The number of nodes and elements in the three models.
Material properties and boundary conditions
The mesh models were imported into Abaqus 2022 (Dassault Systèmes, France) for finite element analysis. As shown in Table 2, and based on previous studies (Shengyuan, 2022), all bone tissues and internal fixation devices were assumed to be homogeneous, isotropic, and linearly elastic materials, and the corresponding material properties were assigned accordingly. According to previous studies (Anwar et al., 2020), the contact interactions and boundary conditions were defined as follows: the interface between cancellous and cortical bone was modeled as a tied contact; the fracture surfaces were defined as sliding contact with a friction coefficient of 0.46 (Hong et al., 2017). The friction coefficient between bone and implants was set to 0.3 (Chen et al., 2004), and that between implant components was set to 0.2 (Lee et al., 2016).
TABLE 2
| Part | Young’s modulus, E (GPa) | Poisson’s ratio, ν |
|---|---|---|
| Cortical bone | 17 | 0.3 |
| Cancellous bone | 1.3 | 0.3 |
| Titanium alloy | 110 | 0.3 |
Material parameters.
As illustrated in Figure 2 and based on previous studies (Yang et al., 2025), three loading conditions were simulated: axial, bending, and torsional loading. The distal end of the femur was fully constrained by restricting all six degrees of freedom. Under axial loading, a uniformly distributed load equivalent to approximately three times the body weight was applied to the femoral head to simulate the peak load experienced by the hip joint during walking. A lateral load of 175 N was applied to represent forces acting on the femur during activities such as normal gait and lateral bending. A torsional moment of 15 Nm was applied to the femoral head to represent rotational loading experienced by the proximal femur during daily activities.
FIGURE 2
Results
Validation of the finite element model
To assess the accuracy and biomechanical reliability of the finite element model, validation analyses were performed at both the intact femur level and the fixation model level. First, following commonly adopted methods in previous finite element studies (Keyak et al., 1990; Viceconti et al., 2005), a 700 N axial load was applied to the intact femur model to simulate physiological loading during single-leg stance. The results (Figure 3) showed that the maximum von Mises stress was primarily concentrated in the medial cortical region of the femoral neck, with a peak value of 16.82 MPa. The overall deformation pattern was consistent, and the maximum displacement occurred at the femoral head, with a value of 1.76 mm. The stress distribution pattern indicated that the load was transmitted from the femoral head along the medial cortex of the femoral neck toward the femoral shaft, consistent with the physiological load transfer characteristics of the proximal femur. In addition, both stress and displacement values were comparable to those reported in previous studies (Keyak et al., 1990; Taddei et al., 2004), suggesting that the intact femur model demonstrated reasonable biomechanical consistency. Furthermore, to assess the fixation model, the RN model (Table 3) was analyzed under the same 700 N axial loading condition. The results were compared with those reported in previous finite element and biomechanical studies (Shengyuan, 2022). The stress distribution characteristics and displacement ranges obtained in this study were generally consistent with those reported in the literature, further supporting the reliability of the finite element model for internal fixation analysis.
FIGURE 3
TABLE 3
| Parameters | Present study | Tian et al. (2022) |
|---|---|---|
| Implant von mises stress (MPa) | 149.92 | 160.39 |
| Femoral displacement (mm) | 4.16 | 4.56 |
Comparison results with previous literature.
Stress and displacement distribution
Axial loading
Under axial loading (Figure 4), the PFBN exhibited lower implant stress (444.8 MPa) than RN (481.9 MPa) and TCP (781.0 MPa). A similar trend was observed for femoral stress, with PFBN (113.1 MPa) showing lower values than RN (204.8 MPa) and TCP (326.5 MPa). Displacement followed a comparable pattern: PFBN showed the lowest displacement (13.4 mm), RN exhibited similar values (13.7 mm), and TCP showed higher displacement (20.0 mm).
FIGURE 4
Bending loading
Under bending loading (Figure 5), the implant stress of the PFBN (234.6 MPa) was comparable to that of RN (234.8 MPa), whereas TCP exhibited higher stress (540.5 MPa). Femoral stress in the TCP model (305.8 MPa) was higher than that in PFBN (31.3 MPa) and RN (33.5 MPa). Displacement values were similar between PFBN (9.52 mm) and RN (9.53 mm), whereas TCP exhibited higher displacement (12.49 mm).
FIGURE 5
Torsional loading
Under torsional loading (Figure 6), the PFBN exhibited lower implant stress (296.0 MPa) than RN (309.8 MPa) and TCP (761.2 MPa). Femoral stress was higher in the TCP model (313.5 MPa) than in PFBN (44.5 MPa) and RN (46.0 MPa). Displacement showed a similar trend, with PFBN (4.33 mm) lower than RN (4.57 mm) and TCP (6.29 mm).
FIGURE 6
The biomechanical parameters of the three models under axial, bending, and torsional loading conditions are summarized in Table 4.
TABLE 4
| Load | Parameters | Long PFBN | RN | TCP |
|---|---|---|---|---|
| Axial | VMS of implant models (MPa) | 444.8 | 481.9 | 781.0 |
| VMS of femur models (MPa) | 113.1 | 204.8 | 326.5 | |
| Displacement (mm) | 13.38 | 13.73 | 20.00 | |
| Bending | VMS of implant models (MPa) | 234.6 | 234.8 | 540.5 |
| VMS of femur models (MPa) | 31.32 | 33.50 | 305.8 | |
| Displacement (mm) | 9.517 | 9.525 | 12.49 | |
| Torsional | VMS of implant models (MPa) | 296.0 | 309.8 | 761.2 |
| VMS of femur models (MPa) | 44.52 | 45.98 | 313.5 | |
| Displacement (mm) | 4.330 | 4.570 | 6.290 |
Biomechanical evaluation parameters of the three models under axial, bending, and torsional loading.
Tangential micromotion
CSLIP1 and CSLIP2 represent tangential micromotion of the contact interface in two orthogonal directions and were used to characterize micromotion at the fracture interface. Under axial loading, at the femoral neck fracture interface (Figure 7), the CSLIP1 values for PFBN, RN, and TCP were 0.153 mm, 0.575 mm, and 0.077 mm, respectively, while the corresponding CSLIP2 values were 0.092 mm, 0.433 mm, and 0.055 mm. At the femoral shaft fracture interface (Figure 8), the CSLIP1 values for PFBN, RN, and TCP were 0.102 mm, 0.106 mm, and 0.023 mm, respectively, while the corresponding CSLIP2 values were 0.091 mm, 0.097 mm, and 0.0013 mm, respectively.
FIGURE 7
FIGURE 8
Discussion
This study showed that, compared with two conventional fixation methods, the long PFBN, based on the triangular-supported fixation concept, demonstrated relatively improved stress distribution, displacement control, and fracture-site stability under axial, bending, and torsional loading conditions in the fixation of IFNSF. From a biomechanical perspective, the long PFBN may provide potential advantages in terms of load distribution and structural stability for this type of complex fracture.
The findings of this study suggest that the long PFBN may exhibit several distinct biomechanical characteristics compared with conventional fixation methods. First, in terms of load transfer, the proximal bionic triangular structure combined with distal intramedullary fixation may provide a more continuous load transfer pathway. Load may be transmitted from the femoral head through the proximal triangular structure to the intramedullary nail and subsequently distributed distally along the nail. This configuration may facilitate a more uniform stress distribution and potentially reduce local stress concentration. Second, regarding overall stability, the combined effect of the proximal triangular configuration, intramedullary fixation, and distal locking mechanism may enhance the resistance of the fixation system to axial, bending, and torsional loading. In addition, tangential micromotion at the femoral neck fracture site in the long PFBN model was intermediate between that of the RN and TCP models. Previous studies (Zhao et al., 2025; Ni et al., 2016) have suggested that, under certain conditions, fracture-site micromotion in the range of approximately 0.15 –0.4 mm may be associated with callus formation. However, this range is influenced by multiple factors, including loading conditions, micromotion direction, and the biological environment, and its applicability remains uncertain. In the present study, micromotion in one direction (0.153 mm) fell within this range, whereas that in the other direction (0.092 mm) was slightly below it. These findings may indicate that the long PFBN may limit excessive sliding while maintaining a certain degree of mechanical stimulation. However, whether this biomechanical characteristic translates into a more favorable healing environment remains unclear and requires further experimental and clinical validation. Therefore, the micromotion level observed in the long PFBN model may represent a relatively balanced mechanical environment between fixation stability and mechanical stimulation.
Further analysis of the relationship between structural features and mechanical performance suggests that the design characteristics of the long PFBN may contribute to its observed biomechanical behavior. First, the proximal support screw of the PFBN passes through the tension screw and, together with the proximal nail, forms a triangular stabilizing structure (Zhang Yi-Fan et al., 2024). This triangular configuration is geometrically similar to the distribution of compressive and tensile trabeculae in the Ward’s triangle region of the proximal femur (Ding et al., 2023), which may facilitate a more uniform transfer of load from the femoral head to the femoral shaft. Second, the long PFBN maintains an intramedullary central fixation pattern. Its centralized position may provide mechanical stability while preserving a certain level of physiological stress stimulation, which may help reduce stress shielding effects (Yang et al., 2025). In addition, the threaded locking between the proximal support screw and the main nail may provide angular stability, whereas the limited sliding permitted by the tension screw within the nail channel may contribute to a form of “dynamic stability.” This may help resist excessive shear motion while allowing controlled axial compression under loading conditions (Cheng et al., 2023). It should be noted that these structure–function relationships are primarily inferred from finite element analysis. Their biological implications remain uncertain and require further validation through experimental and clinical studies.
In clinical practice, RN and TCP are commonly used fixation methods for IFNSF. The RN provides intramedullary central fixation and allows simultaneous management of both fractures using a single implant, thereby maintaining continuity of load transfer. In contrast, the TCP strategy employs two fixation systems to stabilize the femoral neck and shaft separately, providing relatively strong local stability. However, both approaches may be associated with certain biomechanical limitations. Proximally, both systems typically adopt parallel screw configurations, which, under complex loading conditions, may be associated with stress concentration at the fixation margins and the screw–bone interface (Cheng et al., 2023), potentially increasing the risk of screw cut-out or loosening. In addition, the parallel configuration lacks a three-dimensional locking effect, which may be associated with complications such as coxa vara, femoral neck shortening (Cheng et al., 2023), and torsional micromotion, potentially influencing the fracture healing environment (Filipov, 2011). Furthermore, in the TCP system, the screws and plate are not integrated into a single construct, which may lead to discontinuous load transfer between components. This may contribute to localized stress concentration within the implant system. Moreover, the rigid fixation provided by the femoral shaft plate may contribute to stress shielding (Olmos et al., 2022), potentially reducing physiological mechanical stimulation at the fracture site and thereby influencing the healing process. In some cases, these factors may be associated with complications such as fixation failure, delayed union, or nonunion.
The findings of this study preliminarily suggest that the long PFBN may exhibit potential biomechanical advantages. For patients with unstable femoral neck fractures combined with comminuted femoral shaft fractures, the anti-rotational capability of the long PFBN may help mitigate certain limitations of conventional reconstruction nails. Compared with combined fixation strategies, its single-implant design may provide a structural basis for reduced surgical invasiveness. However, its minimally invasive characteristics and potential clinical benefits require further validation through well-designed clinical studies. Future research may focus on optimizing the structural parameters of the long PFBN and conducting targeted clinical investigations. In particular, its potential applicability may be further explored in patients with different fracture patterns and varying bone quality.
This study has several limitations that should be acknowledged. First, the finite element model was constructed based on CT data from a single healthy adult male femur, which does not account for variations in bone quality, age-related changes, osteoporosis, sex differences, or fracture complexity in clinical populations. This limitation may affect the generalizability of the findings. Second, soft tissues such as muscles and tendons were not included in the model, although they play an important role in load transmission in the proximal femur. Their exclusion may influence the predicted stress distribution and displacement patterns under physiological conditions. Third, the biomechanical performance of the long PFBN was evaluated only within a deterministic finite element framework, without direct experimental validation. Therefore, the results should be interpreted as comparative biomechanical findings under specific modeling assumptions rather than definitive evidence of clinical superiority. In addition, multiple subject-specific models were not established, which limits the assessment of the robustness of the findings under different conditions. Future studies should incorporate inter-individual variability, more physiologically representative modeling conditions, cadaveric biomechanical experiments, and clinical investigations to further validate and extend the present findings.
Conclusion
In this finite element study, the long PFBN demonstrated relatively favorable biomechanical performance under axial, bending, and torsional loading conditions. These findings may provide comparative biomechanical insights into the performance of different fixation strategies for this complex fracture pattern.
Statements
Data availability statement
The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding authors.
Ethics statement
The studies involving humans were approved by the Medical Ethics Committee of the Hebei Medical University Third Hospital. The studies were conducted in accordance with the local legislation and institutional requirements. The ethics committee/institutional review board waived the requirement of written informed consent for participation from the participants or the participants' legal guardians/next of kin.
Author contributions
ZF: Writing – original draft. KD: Writing – original draft. WL: Validation, Writing – original draft, Visualization, Software. BL: Writing – review and editing, Software, Visualization. TS: Writing – review and editing, Visualization, Software. YZ: Methodology, Writing – review and editing, Data curation. QZ: Writing – review and editing, Supervision. WC: Methodology, Data curation, Funding acquisition, Writing – original draft, Writing – review and editing.
Funding
The author(s) declared that financial support was received for this work and/or its publication. This study was funded by the National Natural Science Foundation of China (Grant No. 82202683) and the National Natural Science Foundation of China (Grant No. 82272578).
Conflict of interest
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Generative AI statement
The author(s) declared that generative AI was not used in the creation of this manuscript.
Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
Supplementary material
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fbioe.2026.1799331/full#supplementary-material
References
1
AlbornoY.AbunimerA.AbuodehY.SalamehM.KayaliH.AhmedG. (2023). The surgical outcomes of fixing ipsilateral femoral neck and shaft fractures: single versus double implants fixation. Eur. Journal Orthopaedic Surgery and Traumatology Orthopedie Traumatologie33 (5), 1613–1618. 10.1007/s00590-022-03312-0
2
AlhoA. (1996). Concurrent ipsilateral fractures of the hip and femoral shaft: a meta-analysis of 659 cases. Acta Orthop. Scand.67 (1), 19–28. 10.3109/17453679608995603
3
AngeliniA.MavrogenisA. F.CrimìA.GeorgoulisJ.SioutisS.BekosA.et al (2021). Double fractures of the femur: a review of 16 patients. Eur. Journal Orthopaedic Surgery and Traumatology Orthopedie Traumatologie31 (7), 1345–1354. 10.1007/s00590-021-02873-w
4
AnwarA.HuZ.AdnanA.GaoY.LiB.NazirM. U.et al (2020). Comprehensive biomechanical analysis of three clinically used fixation constructs for posterior malleolar fractures using cadaveric and finite element analysis. Sci. Reports10 (1), 18639. 10.1038/s41598-020-75819-7
5
BaghelA.KeshavK.KumarA.SharmaP. (2021). Clinicoradiological outcome of concomitant fractures of proximal femur and femoral shaft treated with second-generation cephalomedullary nailing. Cureus13 (6), e15381. 10.7759/cureus.15381
6
BojanA. J.JönssonA.GranhedH.EkholmC.KärrholmJ. (2018). Trochanteric fracture-implant motion during healing - a radiostereometry (RSA) study. Injury49 (3), 673–679. 10.1016/j.injury.2018.01.005
7
ChengX.YangY.ZhuJ.LiG.ChenW.WangJ.et al (2023). Finite element analysis of basicervical femoral neck fracture treated with proximal femoral bionic nail. J. Orthopaedic Surgery Research18 (1), 926. 10.1186/s13018-023-04415-y
8
ChenW.-P.TaiC. L.ShihC. H.HsiehP. H.LeouM. C.LeeM. S. (2004). Selection of fixation devices in proximal femur rotational osteotomy: clinical complications and finite element analysis. Clin. Biomechanics (Bristol, Avon)19 (3), 255–262. 10.1016/j.clinbiomech.2003.12.003
9
DahujaA.BhattyS.BansalK.KaurR.ShayamR. (2018). Role of PFN in ipsilateral fracture neck and shaft femur: a single solution to double fracture. Int. J. Res. Orthop.4 (3), 384–388. 10.18203/issn.2455-4510.IntJResOrthop20181472
10
DingK.ZhuY.ZhangY.LiY.WangH.LiJ.et al (2023). Proximal femoral bionic nail-a novel internal fixation system for the treatment of femoral neck fractures: a finite element analysis. Front. Bioengineering Biotechnology11 (5 Dec), 1297507. 10.3389/fbioe.2023.1297507
11
DuC. G.ZhangY. Z.ChenW. (2016). Zhonghua wai ke za zhi. Chin. Journal Surgery54 (7), 553–557. 10.3760/cma.j.issn.0529-5815.2016.07.017
12
FilipovO. (2011). Biplane double-supported screw fixation (F-technique): a method of screw fixation at osteoporotic fractures of the femoral neck. Eur. Journal Orthopaedic Surgery and Traumatology Orthopedie Traumatologie21 (7), 539–543. 10.1007/s00590-010-0747-9
13
GadegoneW. M.ShivashankarB.LokhandeV.SalphaleY. (2017). Augmentation of proximal femoral nail in unstable trochanteric fractures. SICOT-J3, 12. 10.1051/sicotj/2016052
14
HongJ.-B.DanY.OuyangL.LiuY.XiongL. M.LiS.et al (2017). Biomechanical study on different lengths of PFNA fixation for unstable intertrochanteric femoral fractures. J. Musculoskeletal and Neuronal Interactions17 (4), 299–302.
15
KeyakJ. H.MeagherJ. M.SkinnerH. B.MoteC. D. (1990). Automated three-dimensional finite element modelling of bone: a new method. J. Biomedical Engineering12 (5), 389–397. 10.1016/0141-5425(90)90022-f
16
LeeP.-Y.LinK. J.WeiH. W.HuJ. J.ChenW. C.TsaiC. L.et al (2016). Biomechanical effect of different femoral neck blade position on the fixation of intertrochanteric fracture: a finite element analysis. Biomed. Tech. Biomed. Engineering61 (3), 331–336. 10.1515/bmt-2015-0091
17
MohanK.EllantiP.FrenchH.HoganN.McCarthyT. (2019). Single versus separate implant fixation for concomitant ipsilateral femoral neck and shaft fractures: a systematic review. Orthop. Reviews11, 7963. 10.4081/or.2019.7963
18
NiM.NiuW.WongD. W. C.ZengW.MeiJ.ZhangM. (2016). Finite element analysis of locking plate and two types of intramedullary nails for treating mid-shaft clavicle fractures. Injury47 (8), 1618–1623. 10.1016/j.injury.2016.06.004
19
OlmosA. A. R.FertuzinhosA.CamposT. D.DiasI. R.ViegasC. A.PereiraF. A. M.et al (2022). Osteosynthesis metal plate system for bone fixation using bicortical screws: Numerical-Experimental characterization. Biology11 (6), 940. 10.3390/biology11060940
20
OstrumR. F.TornettaP.WatsonJ. T.ChristianoA.VafekE. (2014). Ipsilateral proximal femur and shaft fractures treated with hip screws and a reamed retrograde intramedullary nail. Clin. Orthop. Relat. Research®472 (9), 2751–2758. 10.1007/s11999-013-3271-5
21
SamsamiS.AugatP.RouhiG. (2019). Stability of femoral neck fracture fixation: a finite element analysis. Proc. Institution Mech. Eng. Part H, J. Engineering Medicine233 (9), 892–900. 10.1177/0954411919856138
22
ShengyuanT. (2022). Finite element analysis of three fixation methods for femoral shaft fractures combined with ipsilateral femoral neck fractures. Guiyang: Guizhou Medical University. 10.27045/d.cnki.ggyyc.2022.000466
23
SinghR.RohillaR.MaguN. K.SiwachR.KadianV.SangwanS. S. (2008). Ipsilateral femoral neck and shaft fractures: a retrospective analysis of two treatment methods. J. Orthopaedics Traumatology Official Journal Italian Soc. Orthop. Traumatology9 (3), 141–147. 10.1007/s10195-008-0025-3
24
TaddeiF.PancantiA.VicecontiM. (2004). An improved method for the automatic mapping of computed tomography numbers onto finite element models. Med. Engineering and Physics26 (1), 61–69. 10.1016/s1350-4533(03)00138-3
25
TsaiC.-H.HsuH. C.FongY. C.LinC. J.ChenY. H.HsuC. J. (2009). Treatment for ipsilateral fractures of femoral neck and shaft. Injury40 (7), 778–782. 10.1016/j.injury.2009.03.009
26
VicecontiM.OlsenS.NolteL. P.BurtonK. (2005). Extracting clinically relevant data from finite element simulations. Clin. Biomechanics (Bristol, Avon)20 (5), 451–454. 10.1016/j.clinbiomech.2005.01.010
27
WolinskyP. R.JohnsonK. D. (1995). Ipsilateral femoral neck and shaft fractures. Clin. Orthop. Relat. Res.318, 81–90.
28
YangY.WuD.ChengX.HeW.ChenW.ZhangY.et al (2025). Biomechanical evaluation of the triangular support structure of the proximal femoral bionic nail compared to conventional long intramedullary nails for subtrochanteric fractures. Front. Bioengineering Biotechnology13 (30), 1579842. 10.3389/fbioe.2025.1579842
29
ZhangK.ChenW.ZhangY. (2024a). Proximal Femur Bionic Nail (PFBN): a Panacea for unstable intertrochanteric Femur fracture. Engineering37, 152–158. 10.1016/J.ENG.2024.01.010
30
ZhangY.-F.RenC.YaoM. X.ZhaoS. G.DingK.WangH. C.et al (2024b). Biomechanical comparison of the therapeutic effect of a novel proximal femoral bionic intramedullary nail and traditional inverted triangle hollow screw on femoral neck fracture. J. Orthopaedic Surgery Research19 (1), 359. 10.1186/s13018-024-04770-4
31
ZhaoY.LiJ.LiuY.CuiG.LiZ. (2023). Comparison of reconstruction nails versus dual implants in the treatment of ipsilateral femoral neck and shaft fractures in adults: a meta-analysis and systematic review. BMC Musculoskeletal Disorders24 (1), 800. 10.1186/s12891-023-06933-6
32
ZhaoP.LiR.ChenJ.WangY.GuanJ.WuM. (2025). A biomechanical investigation of three fixation methods for unilateral denis type II sacral fractures using finite element analysis. Front. Bioengineering Biotechnology13, 1631457. 10.3389/fbioe.2025.1631457
33
ZhuY.DingK.LiY.WangH.ChenW.HouZ.et al (2021). Biomechanical comparison of triangle supporting fixation system and gamma nail fixation in the treatment of intertrochanteric fractures of the femur: finite element analysis. Chin. J. Orthop.41 (18), 1361–1366. 10.3760/cma.j.cn121113-20210601-00394
Summary
Keywords
combined approach, finite element analysis, integrated structure, ipsilateral femoral neck and shaft fractures, PFBN
Citation
Fan Z, Ding K, Liu W, Luo B, Shi T, Zhang Y, Zhang Q and Chen W (2026) Finite element analysis of long proximal femoral bionic nail (PFBN) fixation for femoral shaft fractures combined with ipsilateral femoral neck fractures. Front. Bioeng. Biotechnol. 14:1799331. doi: 10.3389/fbioe.2026.1799331
Received
29 January 2026
Revised
26 March 2026
Accepted
06 April 2026
Published
22 April 2026
Volume
14 - 2026
Edited by
Pankaj Pankaj, University of Edinburgh, United Kingdom
Reviewed by
Eberval Gadelha Figueiredo, University of São Paulo, Brazil
Mutalipu Silamujiang, People’s Hospital of Xinjiang Uygur Autonomous Region, China
Updates
Copyright
© 2026 Fan, Ding, Liu, Luo, Shi, Zhang, Zhang and Chen.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Wei Chen, surgeonchenwei@126.com; Qi Zhang, drzhangqi1@163.com
†These authors have contributed equally to this work
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.