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Effects of new assembled titanium mesh cage on the improvement in biomechanical performance of single-level anterior cervical corpectomy and fusion: a finite element analysis

BMC Musculoskeletal Disorders volume 26, Article number: 404 (2025) Cite this article

Abstract

Background

Anterior cervical corpectomy and fusion (ACCF) with Traditional Titanium Mesh Cages (TTMCs) can lead to complications such as cage subsidence, dysphagia, and implant-related issues. These complications suggest that the biomechanical stability of ACCF with TTMC may be insufficient. This study aims to evaluate whether a New Assembled Titanium Mesh Cage (NTMC) can improve the biomechanical performance after ACCF.

Methods

ACCF procedures using both TTMC and NTMC models were constructed and compared. The range of motion (ROM) of the surgical segments and stress peaks in various regions including the endplate, bone-screw interface, facet joints, and adjacent intervertebral discs were analyzed.

Results

The use of NTMC significantly reduced the postoperative ROM of the surgical segments by 80.7%-82.0% compared to ACCF with TTMC. Additionally, stress peaks at the endplate, bone-screw interface, and facet contact force (FCF) were higher in ACCF with TTMC compared to NTMC. TTMC also induced higher stress peaks in the C3/4 and C6/7 intervertebral discs (ranging from 0.2009–6.961 MPa and 0.2477–4.735 MPa, respectively), followed by the NTMC (ranging from 0.1322–3.820 MPa and 0.2227–4.104 MPa, respectively).

Conclusions

The utilization of NTMC, which includes enlarged spacers and emulates endplate geometries, effectively reduces the risks of cage subsidence and instrument-related complications in ACCF. Furthermore, ACCF with NTMC also decreases the risks of dysphagia, facet joint degeneration, and adjacent disc degeneration during the follow-up period by altering the fixing method while maintaining construct stability.

Peer Review reports

Introduction

Anterior cervical corpectomy and fusion (ACCF) is widely regarded as an effective treatment for various conditions, including posterior osteophytes of the vertebral, ossified posterior longitudinal ligament (OPLL), prolapse of free nucleus pulposus, and tumors [1]. This procedure effectively decompresses the compressed spinal cord while restoring the height and curvature of the cervical vertebra [2, 3]. Traditionally, the use of Traditional Titanium Mesh Cages (TTMCs) has been favored in ACCF due to their ability to provide structural support without autografts, thereby reducing donor-site morbidity. Autografts from the iliac crest, fibula, or ribs can lead to complications such as blood loss, infection, and donor-site pain [4]. Instead, resected vertebral bodies and lower-quantity autografts are typically used with TTMCs, resulting in satisfactory clinical outcomes. However, the use of TTMCs in ACCF is not without drawbacks. Studies have shown a high rate of TTMC subsidence, which can cause neck pain and neurological deterioration [5, 6]. In severe cases, implant failure may cause the TTMC to protrude into the spinal canal and compress the spinal cord, potentially leading to paralysis or even death. [7]. The main reason may lie in that the endplates are uneven whereas both sides of TTMC are flat, and the mismatch between them results in a small contact area and a large stress concentration. For another, dysphagia is one of the common complications that occur frequently after anterior cervical spine surgery [8] and the cervical anterior titanium plate has been considered an independent risk factor of dysphagia because it may incite an inflammatory reaction of the prevertebral fascia according to a previous study [9].

To address these complications, a New Assembled Titanium Mesh Cage (NTMC) has been designed. The NTMC consists of two spacers that match the shapes of the upper and lower endplates, located on both sides of the Titanium Mesh Cage (TMC). In contrast to the TTMC, the NTMC eliminates the need for an anterior titanium plate and instead fixes the TMC to the spacer using a special slot structure. Furthermore, two screws are inserted into the upper and lower vertebral bodies via each spacer to enhance the stability of the anterior spinal column.

This study aims to evaluate whether the use of NTMC can improve the biomechanical performance of ACCF. By addressing the issues of subsidence and dysphagia associated with TTMCs, it is hypothesized that the NTMC can provide enhanced stability and reduce complications.

Materials and methods

Finite element model of the intact lower cervical spine

An intact C2 - 7 finite element (FE) model was constructed with the following steps. Computed tomography (CT) images (SOMATOM Definition AS +, Siemens, Germany) of the C2 - 7 cervical spine were obtained from a young patient (33 years of age; height, 175 cm; weight, 72 kg) and were then imported into Mimics 17.01(Materialise Corporation, Belgium) to reconstruct the surface model of each vertebra. Solid models of the cortical shell, cancellous bone, and intervertebral disk were constructed in Geomagic Studio 2015 (Raindrop Geomagio Inc. USA). Meshes of the bones, intervertebral disks, and ligaments were constructed using Hypermesh 14.0 (Atari Corporation. USA) and imported into Abaqus 6.14 (Dassault System. France) for material property definitions, model assembly, and FE analysis [10].

Figure 1 shows the FE model of the intact C2 - 7 cervical spine, which consisted of 6 vertebrae, 5 intervertebral disks, the anterior longitudinal ligament, the posterior longitudinal ligament, the capsular ligament, the interspinous ligament, the supraspinous ligament, and the ligamentum flavum. A 0.4-mm-thick shell consisting of cortical bone [11] and the nucleus pulposus was modeled as an incompressible inviscid fluid, and the intervertebral disc was divided into the annulus fibrosus and nucleus pulposus with a volume ratio of 7:3 [12]. The annulus fibrosus was modeled as an annulus ground substance embedded with annulus fibers. Annulus fibers surrounded the ground substance with an inclination to the transverse plane between 15° and 45° [13]. The ligaments were defined as 3D truss elements acting nonlinearly in tension only via the hyperelastic material designation in Abaqus, which allowed for the definition of axial stiffness as a function of axial strain. All the ligaments were attached to the corresponding vertebrae using tension-only truss elements [12]. A convergence analysis was performed to ensure that the maximum changes in the strain energy were < 5%. The element types and material properties used in the FE model are shown in Table 1, which is based on previous publications [12, 14].

Fig. 1
figure 1

Finite element model of the intact C2-7 cervical spine: (A) front view, (B) sagittal view, (C) intact intervertebral Disk. D Annulus fiber

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Table 1 Material properties assigned to the finite element model
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FE model of the ACCF procedures

Figure 2A and B show the FE model of ACCF using the NTMC for interbody fusion. After the corpectomies, an NTMC with a 12-mm diameter was implanted into the space. Both ends of the NTMC were enlarged by adding a spacer to each end, which matched the shapes between the endplates by measuring the patient's preoperative CT scan data. Good matching between the endplate and spacer was achieved using the Boolean calculation to remove the portion that overlapped with the vertebral body. The contact area in the spacer-endplate interface was 3.57 cm2. Different from the TTMC, the anterior titanium plate was removed in NTMC, the TMC was fixed to the spacer by the slot structure (Fig. 3C), and the screws were inserted into the upper and lower vertebral bodies through each spacer. For all surgical models, the interfaces at the cage endplate and bone screw were defined as a tied contact condition to simulate a complete fusion status [15].

Fig. 2
figure 2

Finite element models of the surgical procedures: (A) front view of ACCF using the TTMC, (B) the structure of TTMC

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Figure 3A and B show the FE model of ACCF using the NTMC for interbody fusion. After the corpectomies, an NTMC with a 12-mm diameter was implanted into the space. Both ends of the NTMC were enlarged by adding a spacer to each end, which matched the shapes between the endplates by measuring the patient's preoperative CT scan data. Good matching between the endplate and spacer was achieved using the Boolean calculation to remove the portion that overlapped with the vertebral body. The contact area in the spacer-endplate interface was 3.57 cm2. Different from the TTMC, the anterior titanium plate was removed in NTMC, the TMC was fixed to the spacer by the slot structure (Fig. 3C), and the screws were inserted into the upper and lower vertebral bodies through each spacer. For all surgical models, the interfaces at the cage endplate and bone screw were defined as a tied contact condition to simulate a complete fusion status [15].

Fig. 3
figure 3

Finite element models of the surgical procedures: (A) front view of ACCF using the NTMC, (B) the structure of NTMC, (C) the TMC and the spacer are connected by the slot structure

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Loading and boundary conditions

The FE model of intact C2 − C7 segments was fixed at the inferior endplate of C7. Follower loads of 75 N were used to simulate muscle force and head weight. A 1.0-N.m moment and a 75-N follower load were applied to the odontoid of the C2 vertebrae to produce flexion, extension, lateral bending, and axial rotation [16]. The surgical segment ROMs, the stress of the C6 endplate stresses, bone-screw interfacial stresses, facet contact force, and intradiscal pressure were compared between the constructs of ACCF using the TTMC and ACCF using the NTMC. Based on previous studies and literature data, C4/5 and C5/6 were chosen as the implanted levels because they are the most frequently involved levels in clinical practice [17].

Results

Model Validation

The intersegmental ROMs at C2 - 3, C3 - 4, C4 - 5, C5 - 6, and C6 - 7 were 4.29°, 6.49°, 7.45°, 7.35°, and 4.89°, respectively, in flexion; 3.16°, 4.57°, 6.32°, 5.22°, and 4.21°, respectively, in extension; 5.14°, 5.42°, 5.67°, 4.21°, and 3.85°, respectively, in bending; and 2.14°, 3.15°, 4.36°, 3.60°, and 2.08°, respectively, in rotation. As shown in Fig. 4, the intersegmental ROMs in each motor direction showed good agreement with the outcomes of previous publications, which consistency can be as high as 65.8% to 99.7 % 9 [16, 18, 19]. Moreover, a previous study of cadaver specimens in vitro, the intersegmental ROMs at C2 - 3, C3 - 4, C4 - 5, C5 - 6, and C6 - 7 were 3.90°, 7.05°, 6.02°, 7.93°, and 5.33°, respectively, in flexion; 2.21°, 4.97°, 5.32°, 7.81°, and 5.61°, respectively, in extension; 4.32°, 6.54°, 4.07°, 4.28°, and 2.79°, respectively, in bending; and 2.37°, 3.97°, 5.13°, 6.22°, and 3.63°, respectively, in rotation, which consistency is up to 98.4% [12].

Fig. 4
figure 4

The predicted ROMs of the intact model are validated by previously published studies

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ROMs of the surgical segments

As shown in Fig. 5, the ROMs of the intact C4 - 6 model in flexion, extension, bending, and rotation were 14.8°, 11.55°, 9.86°, and 7.96°, respectively. Postoperatively, the ROMs of ACCF using a TTMC and ACCF using the NTMC were significantly reduced to 5.28° and 0.98°, respectively, in flexion; 5.38° and 0.97°, respectively, in extension; 5.55° and 1.03°, respectively, in bending; and 2.85° and 0.55°, respectively, in rotation. The differences in the surgical segment ROMs between the TTMC and NTMC can be as much as 82.0%, and the differences were significant between the two groups, which is similar to previous literature [20].

Fig. 5
figure 5

Comparisons of the ROMs of the surgical segments (C4-C6) among the intact model, TTMC and NTMC model

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Cortical endplate stresses

Figure 6A shows the maximum stresses in the C6 superior endplates. The endplate stress peaks were higher in the construct of ACCF using a TTMC, wherein the stresses were 4.47, 21.27, 14.35, and 23.89 MPa in flexion, extension, bending, and rotation, respectively. In the same direction of movement, the endplate stress peaks were lower by using the NTMC in ACCF, which reduced to 2.05, 4.38, 3.91, and 4.34 MPa, respectively. The stress distributions in the C6 superior endplates are shown in Fig. 6B.

Fig. 6
figure 6

A Comparisons of the Maximum von Mises stresses in the C6 superior endplate between TTMC and NTMC model; (B) The stress cloud map of the C6 superior endplates between TTMC and NTMC model

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Stress at the bone-screw interface

The maximum von Mises stresses in the screw interface are shown in Fig. 7A. In the ACCF using a TTMC model, the stresses at the titanium bone–screw interface in flexion, extension, lateral bending, and axial rotation were 40.04, 153.23, 134.79, and 103.57 MPa, respectively. In the ACCF using an NTMC model without anterior titanium plate fixation, the stresses at the bone-screw interfacial in flexion, extension, lateral bending, and axial rotation were 18.62, 14.41, 49.28 and 41.13 MPa, respectively. The stress cloud map in the C6 bone-screw interfacial stresses between the two models is shown in Fig. 7B.

Fig. 7
figure 7

A Comparisons of the Maximum von Mises stresses in the C6 bone-screw interfacial between TTMC and NTMC model; (B) The stress cloud map of the C6 bone-screw interfacial stresses between TTMC and NTMC model

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Facet contact force at the surgical and adjacent segments

The facet contact force (FCF) at the surgical and adjacent segments is shown in Fig. 8. The FCF in the TTMC model was 32.02, 33.86, 8.59, 9.01, and 23.67 MPa in the supra-adjacent (C2/3, C3/4), surgical (C4/5, C5/6) and infra-adjacent segments (C6/7), respectively, occurring under the extension moment. In the NTMC model, the FCF of the supra-adjacent (C2/3, C3/4), surgical (C4/5, C5/6) and infra-adjacent segments (C6/7) decreased to 19.70, 4.51, 0.02, 1.10, and 12.59 MPa, respectively. In the intact model, the FCF of the supra-adjacent (C2/3, C3/4), surgical (C4/5, C5/6) and infra-adjacent segments (C6/7) were 18.86, 18.35, 20.32, 21.38, and 20.89 MPa under the extension moment, respectively.

Fig. 8
figure 8

Facet contact force in extension at all segments among the intact model, TTMC and NTMC model

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Stress on the C3/4 intervertebral disc

Intradiscal pressure (IDP) measures at the supra-adjacent (C3/4) segment is presented in Fig. 9. Compared with the TTMC model, stress on the upper (C3/4) adjacent intervertebral disc in the NTMC model was lower during flexion, extension, lateral bending, and rotation. In the TTMC model, the maximum von Mises stresses on the C3/4 intervertebral disc were 0.20 MPa during flexion; 4.52 MPa during extension; 4.53 MPa during lateral bending; and 6.96 MPa during rotation, respectively. In the NTMC model, the maximum von Mises stresses on the C3/4 intervertebral disc were 0.13 MPa during flexion; 3.60 MPa during extension; 2.17 MPa during lateral bending; and 3.82 MPa during rotation, respectively, and intact model, the maximum von Mises stresses on the C3/4 intervertebral disc were 0.19 MPa during flexion; by 0.32 MPa during extension; by 0.37 MPa during lateral bending; and by 0.36 MPa during rotation, respectively. The stress distributions on the C3/4 intervertebral disc are shown in Fig. 9B.

Fig. 9
figure 9

A Comparisons of the Maximum von Mises stresses in the IDP of the C3/4 segment among the intact model, TTMC model, and NTMC model; (B) The stress cloud map of IDP of the C3/4 segment between TTMC and NTMC model

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Stress on the C6/7 intervertebral disc

IDP measures at the infra-adjacent (C6/7) segment are presented in Fig. 10. In these two models, the NTMC group had lower stress on the intervertebral disc than the TTMC group. In the TTMC group, the maximum von Mises stresses on the C6/7 intervertebral disc were 0.25 MPa during flexion; 4.00 MPa during extension; 4.37 MPa during lateral bending; and 4.74 MPa during rotation, respectively. In the NTMC group, the maximum von Mises stresses on the C6/7 intervertebral disc were 0.22 MPa during flexion; 2.92 MPa during extension; 2.32 MPa during lateral bending; and 4.10 MPa during rotation, respectively, and intact model, the maximum von Mises stresses on the C6/7 intervertebral disc were 0.21 MPa during flexion; by 0.32 MPa during extension; by 0.33 MPa during lateral bending; and by 0.33 MPa during rotation, respectively. The stress distributions on the C6/7 intervertebral disc are shown in Fig. 10B.

Fig. 10
figure 10

A Comparisons of the Maximum von Mises stresses in the IDP of the C6/7 segment among intact model, TTMC model, and NTMC model; (B) The stress cloud map of IDP of the C6/7 segment between TTMC and NTMC model

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Discussion

Construct stability

This study conducted a comprehensive comparison of the biomechanical stabilities provided by ACCF with TTMC and NTMC models. The results demonstrate that both models significantly reduce the range of motion (ROM) in the surgical segments when compared to the intact model. This indicates that both ACCF with TTMC and NTMC models can achieve strong construct stability in the surgical segments.

Prior studies have consistently concluded that the strong stability observed in the surgical segment is primarily attributed to the fixation provided by the anterior titanium plate [21]. These studies have shown that the anterior titanium plate fixation system offers immediate and rigid fixation for the anterior column, effectively reducing the subsidence rate of the TMC and promoting bony fusion rates [22, 23]. For instance, Tsitsopoulos et al. [24] conducted a cadaveric study comparing the construct stability between a stand-alone cage and an additional plate augmentation. Their findings revealed that the intersegmental ROMs were reduced by only 49.2%− 67.7% in the stand-alone cage group, while the use of the additional plate system significantly reduced the ROMs by 73.7–92.8% [24]. Nayak et al. [25] also discovered that the fixation system provided significantly lower surgical segmental range of motion (ROM) compared to the use of a stand-alone cage in a similar cadaveric study.

However, compared with the TTMC model, in all movement directions, the ROMs of the surgical segments in the NTMC model decreased by 80.7%− 82.0% postoperatively, which concludes that the ACCF with the NTMC model has higher construct stability. In present study, the ACCF with the NTMC model removes the anterior titanium plate, which means that the new model’s stability does not rely on the anterior titanium plate fixation. The possible reasons why the new model can maintain stability lie in its special fixing methods.

One is that the TMC was fixed to the spacers by the slot structure, which can achieve rigid stability and a great combination effect. The other important step is by designing screw paths on the spacers and inserting 2 screws into the upper and lower vertebral bodies through these screw paths at an inclination of 45°, which can offer an immediate fixation for the anterior column. The above-mentioned fixation structures can make the NTMC model connect as a whole and have strong stability, which can substitute the traditional anterior titanium plate structure to some extent.

Multiple meta-analyses show that although anterior titanium plate fixation can offer an immediate and rigid fixation, this is also one of the important independent risk factors that lead to dysphagia after surgery [26]. According to the results of the present study, after removing the anterior titanium plate fixation, the NTMC model can maintain better stability of the anterior column while reducing the incidence of dysphagia after surgery to some degree.

In the present study, similar to previous studies, the boundary conditions of the spacer-bone interfaces were assigned to be tied contacts to simulate the status of bony fusion [14], and the complete fusion status during analyses (tied interfaces) is a limiting assumption. Previous studies have shown that there is no significant change in the force distribution of facet joints during extension with or without follower loads. Compared with the cage-bone interfaces in the TTMC model, the spacer-bone interfaces have a larger area in contact with the whole endplate, which is more beneficial to bone growth and bone fusion. As the bony fusion at the endplate space, the stiffness of the anterior column increases, which further improves the stability of the construct. A recent study found that, compared with immediately after surgery, the ROMs of the surgical level were further reduced by 11.5% when the bony fusion was achieved at the intervertebral space [27].

Therefore, the special fixing methods of the new model and the larger contact area between the spacer and the endplate are the keys to maintaining the construct stability.

Subsidence resistance

TMC subsidence is one of the common postoperative complications in ACCF [28]. The high interfacial stress concentration is an important factor that facilitates the cage penetrating the endplate and inducing cage subsidence [28, 29].

Although cage subsidence has few influences on the clinical outcomes in most patients, some severe cases may induce kyphosis, neurologic deterioration, and instrumental complications because of the significant decrease in intervertebral height and the subsequent increase in stress load within the anterior titanium plate [30].

To address these issues, the NTMC model consisting of two spacers located on both sides of the TMC that match the shapes of the upper and lower endplate was developed, and which contact area in the spacer-endplate interface was 3.57 cm2. The outcomes of endplate stresses showed that ACCF using TTMC for vertebral body construction induced approximately sixfold greater stress peaks on the C6 endplate than the NTMC model (14.5–23.9 vs. 2.0–4.4 MPa, respectively). For the TTMC model, the contact area between the TMC end and the endplate is small (the contact area was 0.31 cm2), which results in a large stress concentration and facilitates cage subsidence.

The present study concluded that the larger the spacer-endplate interface contact area, the lower the subsidence rate of the TMC. In addition, some new cages also have been reported to support this viewpoint. These new cages offered larger contact areas with the endplate by enlarging the surface area and simulating the endplate shapes in the cage end to prevent excessive stress concentration, which effectively dispersed the stress distribution and reduced the subsidence rate [5, 31]. Due to the anatomical structure of the cervical spine among patients being different, it is difficult to achieve perfect anatomical matching with the endplates by using the new cages [32]. However, the postoperative results found that these new cages are still in close contact with the endplates, effectively increasing the contact area, rebuilding the intervertebral height, and dispersing the endplate's stress. By simulating the shape of the endplate, these new cages significantly decreased the interval between the spacer and the endplate compared with conventional TMC with a flat end [5, 31]. Therefore, the reduction of the interval leads to a significant increase in the contact area, which further reduces the stress concentration and decreases the risk of postoperative subsidence [33].

It can be seen from the endplate stress programs that due to the limited interface contact area between TMC and endplate, the stress distribution of using TTMC in ACCF is mainly concentrated on the anterior and lateral parts of the endplate. By using the NTMC in ACCF, due to the spacer simulating the shape of the endplate, the contact area at the cage-endplate significantly expanded, and the stress distribution on the endplate became homogeneous, which reduced the concentration of stress and decreased the subsidence rate of the TMC.

Additionally, there is a crucial point. NTMC contacts the entire endplate, including the peripheral epiphyseal ring. TTMC contacts the middle part of the endplate, excluding the epiphyseal ring. As is well known, the elastic modulus of the epiphyseal ring is much higher than that of the middle part of the endplate, which may be another key factor in the low possibility of postoperative subsidence in NTMC.

Risks of instrument-related complications

In the ACCF using a TTMC model, the stresses at the anterior screw-plate interface in flexion, extension, lateral bending, and axial rotation were 16.519, 16.499, 58.432, and 37.004, respectively. In the ACCF using NTMC for reconstruction induced lower stress peaks in the bone-screw interfaces and no anterior screw-plate stress because of canceling the anterior plate system, which relieved the fatigues of the fixation and facilitated to decrease the risks of screw looseness, screw, and plate breakage.

Compared with the use of TTMC, the reasons for the lower stress loads at the bone-screw interface by implanting the NTMC were attributed to the increase in the contact area at the spacer-endplate interface and the dispersion of the stress distribution, which offered greater stability for the anterior column [5, 29] and decreased the risks of instrument-related complications in ACCF.

Risks of degeneration at adjacent discs

It is of great importance to evaluate the changes in internal stresses at adjacent levels by measuring the IDP at surgical adjacent segments [34]. Increases in IDP at adjacent levels after surgery may be relevant to many reasons, such as discogenic pathology, changes in cervical curvature, and subsequent pain [35]. In addition, the stress load led to the intervertebral disc cells being stimulated by stresses such as compressive stress and tensile stress, which not only increased the change of ROM but also damaged the intervertebral disc to a large extent. Because of offers a better fixation method to improve the stabilities of the cervical spine, the adjacent IDP in the NTMC model was less than that in the TTMC model in all directions, which agreed with the changes of ROM, suggesting that the new model could delay the degeneration at adjacent discs.

Besides, the paravertebral muscle strength played a crucial role in regulating IDP. Therefore, for daily activities, individuals should pay attention to the muscle strength of their neck through exercise to decrease the IDP at adjacent levels after surgery.

Limitations

FE analysis is a traditional style for judging the diagnosis after different surgical strategies and offering treatment options. However, there are still some limitations of the current study. Firstly, we idealized some situations within an acceptable range. The frictionless contact in the facet joint surfaces may lead to potential errors [36, 37]. Any possible micromotion among the TMC-spacers, bone-implant, and bone-screw interface were ignored, which were modeled as a tie. Secondly, although we operated on an in vitro model for surgical simulation and inserted a device in the surgical models, simplified in vitro models may not simulate the actual biomechanical environment during the surgery process, especially for endplates and ligaments at the surgical segments. Thirdly, in this research, we performed the finite element model based on CT data from a 33-year-old patient, which might not take the impact of degenerative pathology into account on the biomechanical properties of the spine. Finally, the present methods for a reasonable estimation of the stress threshold for subsidence are limited. Because of the physiological curvature of the cervical spine is lordotic, the load on the anterior spine would be eccentric with respect to the posterior spine. Therefore, any compressive load is not only pure axial translation but also involves a rotation. As mentioned above, since the spine rotation is not taken into account, our previous stress applied at the interface between the cage and the endplate cannot lead to a reasonable estimation of the stress threshold for subsidence. In addition, due to the subsidence failure is also associated with big shear loads and bending moments, even if the load was following the spine curvature (follower load), we would not be sure that the load would be uniformly distributed across the cage-endplate interface. Thus, the FE model may not be the best representation of the real state. However, the main purpose of this research is to provide a trend rather than actual data. Moreover, various types of TMC have different structural and biomechanical features, and the results of the current study have certain limitations and may not apply to other devices.

Conclusions

The application of the NTMC that possessed enlarged spacers and emulated the endplate geometries has the potential to effectively decrease the risks of cage subsidence and instrument-related complications in ACCF. Additionally, in the ACCF with the NTMC, the anterior titanium plate was removed and offered a better fixation system to stabilize the anterior column, which might decrease the risks of facet joints degeneration, adjacent discs degeneration, and dysphagia during the follow-up by changing the fixing method while maintaining the construct stability.

Data availability

No datasets were generated or analysed during the current study.

Abbreviations

ACCF:

Anterior cervical corpectomy and fusion

ACDF:

Anterior cervical discectomy and fusion

NTMC:

New Assembled Titanium Mesh Cage

CT:

Computed tomography

FCF:

Facet contact force

IDP:

Intradiscal pressure

OPLL:

Ossified posterior longitudinal ligament

ROM:

range of motion

TTMC:

Traditional Titanium Mesh Cage

TMC:

Titanium Mesh Cage

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Acknowledgements

We would like to thank the person who gave assistance to this study.

Funding

This study was supported by the National Natural Science Foundation of China (82172522), Sichuan Province Science and Technology Support Program of China (NO.2020YFS0089), Sichuan Province Science and Technology Support Program of China (NO.2020YFS0077), Post-Doctor Research Project, West China Hospital, Sichuan University (NO. 2019HXBH063), and the Postdoctoral Science Foundation of China (NO. 2020M673240).

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Author notes

  1. Ke-rui Zhang and Yi Yang contributed equally to this manuscript and should be considered co-first authors.

Authors and Affiliations

  1. Department of Orthopedic West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu , Sichuan, 610041, China

    Ke-rui Zhang, Yi Yang, Li-tai Ma, Bei-yu Wang, Chen Ding, Yang Meng, Xin Rong & Hao Liu

  2. School of Nursing, the Hongkong Polytechnic University, Hong Kong, China

    Ya-qin Li

  3. Department of Operation Room, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu , Sichuan, 610041, China

    Ying Hong

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  1. Ke-rui Zhang
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Contributions

KRZ and YY contributed to the design of the study. HL and YQL drafted the manuscript with the help from LTM. YH helped in the statistical analyses. Statistical analyses were discussed with BYW and CD. YM and XR contributed to the revision. All authors have read and approved the final manuscript.

Corresponding author

Correspondence to Hao Liu.

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Because this is a finite element study, ethics approval and consent to participate were not involved. Written informed consent was obtained from all individual participants included in this study. We confirm that all methods were performed by the relevant guidelines and regulations.

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The authors declare no competing interests. 

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Zhang, Kr., Yang, Y., Li, Yq. et al. Effects of new assembled titanium mesh cage on the improvement in biomechanical performance of single-level anterior cervical corpectomy and fusion: a finite element analysis. BMC Musculoskelet Disord 26, 404 (2025). https://doiorg.publicaciones.saludcastillayleon.es/10.1186/s12891-025-08625-9

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BMC Musculoskeletal Disorders

ISSN: 1471-2474

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