A Three-Dimensional Finite Element Analysis for the Stability of Tibial Plateau Prosthesis in Improved Unicompartmental Knee Arthroplasty

A Three-Dimensional Finite Element Analysis for the Stability of Tibial Plateau Prosthesis in Improved Unicompartmental Knee Arthroplasty | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A Three-Dimensional Finite Element Analysis for the Stability of Tibial Plateau Prosthesis in Improved Unicompartmental Knee Arthroplasty Shuaixian Tao, Jidong Wang, Yurong Zhao, Jiumei Luosong, Zhaowei Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6137782/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background The primary treatment for end-stage unicompartmental knee osteoarthritis is unicompartmental knee arthroplasty. Reducing postoperative complications following unicompartmental knee arthroplasty has become a focal point of current research. Objective This study aimed to investigate the effects of stress magnitude and distribution on the tibial plateau prosthesis and tibial structure after conventional medial knee arthroplasty and modified surgery using finite element analysis. By comparing the two surgical methods, the advantages and feasibility of the modified surgery were evaluated. Method Models of unicompartmental knee arthroplasty with a fixed platform were constructed using Workbench 18.2 software, including models without fixed columns, models with fixed columns, and models with fixed columns and bone cement. To restore the normal physiological structure of the knee joint to a greater extent, the posterior inclination angle of the tibial fixation platform prosthesis was set to 5°. A vertical downward load of 1000 N was applied to the center of the tibial surface of the three models. The stress data of the tibial fixation platform prosthesis and the tibia under the prosthesis were observed and compared in each model. Result When there is a cement pile under the fixed platform column, the von Mises stress, first principal stress, and strain of the tibia are all lower than the other two cases. Therefore, the tibia with bone cement piles has less deformation and is more stable under stress compared to the other two structures of the tibia. Health sciences/Diseases Health sciences/Medical research knee osteoarthritis Fixed platform Unicompartmental replacement Biomechanics Finite element analysis Technological improvement Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 1 Introduction The knee joint is the largest weight-bearing joint in the lower limbs of the human body and is prone to knee osteoarthritis (KOA) [1] . The main clinical manifestations of KOA are progressive degeneration of cartilage, narrowing of joint spaces compared to anatomical spaces, and formation of osteophytes around the knee joint, leading to joint pain and limited mobility [2] . Due to the physiological characteristics of the knee joint, degeneration of the medial meniscus is more common than that of the lateral meniscus, which can lead to an increase in pressure on the medial compartment joint cartilage and accelerate the development of medial compartment osteoarthritis in the knee joint [3] . The knee joint first undergoes knee inversion, which means that the load is more concentrated in the medial compartment. This inversion will lead to higher mechanical stress and inner wear [4] . Compared with the lateral compartment, the medial compartment of the knee bears higher compressive stress and contact pressure [5] . In a normally inverted knee, the medial compartment typically bears 60-70% of the total intrinsic compressive load [6,7] , while the medial meniscus bears greater pressure, making it more prone to tearing under severe load conditions. Knee inversion further increases the load on the medial compartment. Research has shown that the pressure in the medial compartment increases significantly with the adjustment of varus [8] .This also explains why knee osteoarthritis is more common in the medial compartment of the knee joint. The degeneration of knee cartilage leads to varus deformity, further increasing the pressure in the medial compartment, resulting in a vicious cycle of aggravation of the medial knee joint bone joint, while other compartments are not affected. This also provides a theoretical basis for unicompartmental replacement surgery of the medial compartment of the knee joint. Compared to total knee arthroplasty, unicompartmental arthroplasty aims to maintain knee function and improve patient prognosis by only replacing the affected compartment. It is a knee conserving surgery that preserves bone mass and anterior and posterior cruciate ligaments, as well as the lateral compartment. It has the advantages of minimal trauma, less bleeding, shorter hospital stay, better proprioceptive and motor abilities, and good patient satisfaction [9-12] . However, it is accompanied by a high revision rate of unicompartmental replacement surgery, with a 5-year revision rate of 7% -15% [13] . The high revision rate of unicompartmental replacement is highly correlated with postoperative complications [14.15] , such as tibial periprosthetic fractures, tibial prosthesis collapse, polyethylene pad wear, and so on [16] . How to reduce postoperative complications and revision rates has become a hot topic at present. Therefore, after more than 400 cases of unicompartmental replacement surgery, we propose to make technical improvements to the knee unicompartmental replacement surgery. On the basis of the original tibial plateau prosthesis fixed column, we deepen the fixed column and build a bone cement column to increase the support and stability of the tibial plateau prosthesis. Three-dimensional finite element analysis(3D FEA) is a computational method used to predict the behavior of materials in three-dimensional space under various forces. In the field of orthopedics, this technology is valuable for designing and testing implants. It allows for a detailed analysis of the performance of implants in complex anatomical structures [17] . In medical applications, 3D FEA is used to create patient specific biomechanical models, enabling accurate analysis of stress distribution in tissues and organs. This is crucial for understanding the mechanical behavior of biological structures under load. 3D FEA has the advantage of creating physically accurate patient specific biomechanical models based on in vivo imaging data. It allows for precise calibration in complex environments through reverse analysis techniques, enabling the study of tissue stress and contact pressure distribution. 3D FEA is a powerful tool for evaluating the mechanical behavior and stability of these prostheses under various conditions. This analysis helps to understand the stress distribution, micro motion, and overall biomechanical performance of the prosthesis, which is crucial for optimizing design and surgical outcomes. The aim of this study is to use finite element analysis to establish models of tibial plateau prosthesis without fixation, with fixed column, and with fixed column+bone cement column unicompartmental replacement surgery. By setting specific conditions to compare the stress and strain of the tibial plateau prosthesis and tibia in each model, the advantages and clinical feasibility of the improved technique of knee unicompartmental replacement surgery (deepening of tibial plateau prosthesis fixed column) are explored, providing reference and guidance for the technical improvement of clinical surgery. 2 Materials and Methods 2.1 Design the establishment and finite element analysis of models without fixed columns, with fixed columns, and with fixed columns and bone cement for medial knee joint fixation platform unicompartmental replacement surgery. 2.2 Materials 2.2.1 Software configuration Workbench 18.2, Mimics 20.0, Geomagic 2013, SOLIDWORKS 2017. The above software generated Figure 1-10. 2.2.2 Selection of prostheses Fixed platform unicompartmental prosthesis (Zimmer-Biomet, USA) 2.2.3 Material properties and contact conditions After considering the contact conditions between the prosthesis and the tibia, the mechanical performance parameters of the titanium alloy material are shown in Table 1. Grid division is crucial for finite element analysis, directly affecting the accuracy and speed of the solution. The number of grids is shown in Table 2. Table 1 Material Parameters Elastic modulus/GPa Poisson's ratio Cortical bone 15 0.33 Trabecular bone 0.12 0.33 Fixed platform 200 0.3 Bone cement pile 2.1 0.3 Table 2 Number of grids No fixed column Fixed column Fixed column + bone cement pile Cortical bone 369043 369043 369043 Trabecular bone 488102 488214 487324 Fixed platform 35177 38344 38344 Bone cement pile 0 0 1464*2 total 892322 895601 897639 2.3 Methods 2.3.1 Boundary Conditions and Load Application To simulated the normal walking state under physiological load conditions, the load was applied to the joint surface, to replicate the actual stress environment. The distal end of the tibia and a portion of the shaft were removed while preserving the tibial plateau. To more closely restore the physiological structure of the knee joint, the fixed platform prosthesis was set at an angle of 5° with the horizontal plane. Fixed constraints were applied at the bottom of the model, fully constraining all directions of the bottom surface. A vertical load of 1000N was applied to the upper surface of the tibia to simulate the physiological load at the knee joint when a normal adult stands on both feet. Based on the physiological distribution, the load was evenly distributed with 60% on the medial platform and 40% on the lateral platform of the tibia, to simulate the physiological state as closely as possible. The boundary conditions are shown in Figure 1. The boundary conditions were consistent across all three scenarios. 2.3.2 Model Establishment A three-dimensional model of a fixed platform unicompartmental prosthesis and tibia was established using the computer-aided design software Workbench 18.2. The tibial model was reconstructed based on medical imaging data, utilizing titanium alloy as the prosthetic material (Figure 2 to 6). 3 Results 3.1 von Mises stress Von Mises stress is a critical parameter for evaluating the deformation behavior of materials under composite stress states.Represents the equivalent stress in three-dimensional situations where materials are subjected to a combination of normal stress (tension or compression) and shear stress (shear force in different directions). By calculating von Mises stress, complex stress states can be simplified into a single value, facilitating the evaluation of material strength and stability. The positions of the maximum and minimum values were consistent across the three cases. Compared with the first two cases, the von Mises stress in the tibia was minimized when a bone cement pile was present. (Figures 7 and 8). 3.2 First principal stress The first principal stress indicates the direction and magnitude of the maximum normal stress that occurs in a material under a composite stress state. It represents the maximum tensile or compressive stress in a specific direction within the material, providing crucial information for designing and evaluating the safety of structures. By analyzing the first principal stress, the bearing capacity of the material in a specific direction can be determined to ensure that the structure does not exceed its ultimate strength under actual usage conditions. The first principal stress was minimized when a bone cement pile was present under the fixed column of the fixed platform(Figures 9 and 10). 3.3 Strain Strain refers to the degree of deformation of a material under external loading or deformation. It describes the relative displacement and deformation within the material. By analyzing strain, the degree of deformation and distortion of materials under specific loads or loading conditions can be determined, thereby evaluating the stability, safety, and performance of the structure. The tibial strain was minimized when a bone cement pile was present under the fixed platform column(Figures 11 and 12). 4 Application in surgery Based on the aforementioned results, the surgical technique was applied by drilling two fixed bolt holes in the temporary fixed platform mold and deepening the two fixed bolt holes of the tibia using a bone hammer and the tail end of a footstool (Figure 13). The postoperative imaging data are shown in Figure 14. 5 Discussions Unicompartmental knee arthroplasty(UKA), also known as unicompartmental arthroplasty, is primarily used to treat knee arthritis, especially in patients with severe cartilage wear or joint deformities [18] . In the early 1950s, McKeever first proposed the concept that osteoarthritis could be confined to a specific compartment in the knee joint and subsequently implanted the first unicompartmental knee prosthesis in 1952 [19] . In 1968, Gunston developed a multi center knee prosthesis that more accurately replicated knee joint kinematics while preserving the cruciate ligament. The Oxford femoral prosthesis, first used in 1982, consisted of a spherical joint surface femoral prosthesis and a flat tibial prosthesis. An unconstrained high-density polyethylene "meniscus" bearing, which conformed to the metal component and was maintained by its shape and soft tissue tension, was inserted between the two components. This design was adjusted in 1987 to lower the anterior lip of the meniscus bearing to prevent it from extending onto the femur. The third generation Oxford UKA was launched in 1998, featuring includes a larger size range and instrumentation designed for minimally invasive surgery [20] . UKA is one of the methods for treating unicompartmental knee inflammation, which involves replacing the damaged area to alleviate knee pain and improve patients' daily living abilities. With the improvement of unicompartmental technology and continuous optimization of prosthesis design, UKA has garnered significant interest as an effective treatment for knee arthritis, with advantages such as a wide range of motion, better physical sensation, and high postoperative scores [21] . However, its high revision rate and complications, including postoperative prosthesis loosening, periprosthetic fractures, and tibial plateau collapse, cannot be overlooked. Knee osteoarthritis patients often suffer from osteoporosis, which has been shown to be related to complications such as postoperative prosthesis loosening, fractures around the prosthesis, and collapse of the tibial plateau [22] . With the increasing aging population in China, minimizing complications while preserving the benefits of UKA has become a focal point of current research. Therefore, we proposed improvements to the UKA surgical technique and validated their significance through 3D FEA. During UKA surgery, after inserting a temporary bone plate (tibial plateau trial) for tibial fixation, a conventional gun drill was used to drill bolt holes. Subsequently, a foot pedal and bone hammer were used to deepen the drilling column from its original height of 6.85mm to 10mm. After fully filling the space with bone cement, the tibial plateau prosthesis was placed, and the area beneath the fixation column was filled with bone cement to form a bone cement column. Using finite element analysis software, we established models of knee joint medial fixed platform unicompartmental replacement surgery without fixed columns, with fixed columns, and with fixed columns and bone cement columns. Based on the load distribution ratio of the medial and lateral compartments of the knee joint, we assumed that the medial compartment bears 60% of the normal standing knee joint pressure load under human physiological conditions. By setting specific boundary conditions, we simulated and analyzed the knee joint unicompartmental replacement surgery model as closely as possible to real conditions. The finite element analysis results demonstrated that when a bone cement pile was present under the fixed platform column, the von Mises stress, first principal stress, and strain of the tibia were lower than in the other two scenarios. Platforms with bone cement piles exhibited better mechanical properties under various load conditions, resulting in less tibial deformation. This finding strongly supports the evaluation of one of the key factors for surgical success: the stability of the prosthesis and bone. In orthopedics, the elastic modulus is often used to describe material stiffness. Compared with tibial plateau prostheses, cortical bone has a lower hardness [23] . The elastic modulus is a key parameter in biomechanics, defining a materials ability to deform under stress and recover its original shape after stress relief. The introduction of a tibial plateau prosthesis creates a significant difference in elastic modulus at the prosthesis-bone interface, leading to the stress shielding effect [24.25] . Some scholars have investigated special treatments and adjustments of tibial plateau prostheses to reduce the elastic modulus at the contact surface with bone tissue, matching it as closely as possible to minimize the stress shielding effect and ensure the long-term success of prosthesis implantation [25] . Similarly, this study deepened the hole under the original tibial plateau fixation column and filled it with bone cement, creating a whole and form a lower elastic modulus at the bone contact surface. Compared with the large difference in elastic modulus caused by direct contact between the original fixation column and cancellous bone, this approach plays an intermediate transitional role and enhances biomechanical compatibility. Additionally, we proposed the "column" theory, which likens the deepening of the fixed column of the tibial plateau prosthesis to deepening the foundation of a house. The deeper the foundation, the more stable the structure, thereby increasing the support and stability of the tibial plateau prosthesis in UKA surgery. Although 3D FEA largely simulates the physiological state of bone structure, it still has limitations and cannot exclude interference from muscles and other unpredictable factors. It also cannot directly represent clinical results. However, this study provides valuable information for clinical surgical techniques and lays a theoretical foundation for future clinical experiments. Further research is needed to determine whether the advantages of this improved surgical technique can be applied to obese and osteoporotic patients. Future studies can optimize material selection, prosthesis design, and surgical techniques to enhance the effectiveness of artificial joint replacement surgery. Declarations Funding Not applicable. Author Contribution S.T. and J.W. and Y.Z. wrote the main manuscript text. J.L. and Z.L. prepared figure 13 and 14. Z.L.have drafted the work and substantively revised it. S.T. and J.W. and Y.Z. contributed equally as co-first authors. All authors reviewed the manuscript. Data Availability All data generated or analysed during this study are included in this published article. Human Ethics and Consent to Participate declarations Not applicable. References GBD 2015 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016 Oct 8;388(10053):1545-1602. Castañeda S, Roman-Blas JA, Largo R, et al. Osteoarthritis: a progressive disease with changing phenotypes. Rheumatology (Oxford). 2014 Jan;53(1):1-3. Yadav S K, Shirol V S, Chavan R, et al. Microscopic Structural Changes in Osteoarthritic Menisci of the Human Knee Joint. Journal of the Scientific Society. 2022, 49(3): 310-317. Russell EM, Miller RH, Umberger BR, et al. Lateral wedges alter mediolateral load distributions at the knee joint in obese individuals. J Orthop Res. 2013 May;31(5):665-71. Devaraj A K , Acharya K K V , Adhikari R .Comparison of Biomechanical Parameters between Medial and Lateral Compartments of Human Knee Joints.Bentham Science Publishers B.V. 2020(1). Putnis S, Neri T, Parker D. Outcomes of Surgery for Medial Arthrosis. Osteotomy About the Knee: A Comprehensive Guide. 2020: 47-63. Mø lgaard C M, Kersting U G. The effect of shoe design and lateral wedging on knee loading[M]//Proc. Of Int. Society of Biomech. XXIII. Brussels, Belgium. 2011. Willinger L, Lang JJ, Berthold D, et al. Varus alignment aggravates tibiofemoral contact pressure rise after sequential medial meniscus resection. Knee Surg Sports Traumatol Arthrosc. 2020 Apr; 28(4):1055-1063. Lim JW, Cousins GR, Clift BA,et al. Oxford unicompartmental knee arthroplasty versus age and gender matched total knee arthroplasty - functional outcome and survivorship analysis. J Arthroplasty. 2014 Sep; 29(9):1779-83. Newman J, Pydisetty RV, Ackroyd C. Unicompartmental or total knee replacement: the 15-year results of a prospective randomised controlled trial. J Bone Joint Surg Br. 2009 Jan; 91(1):52-7. Liddle AD, Judge A, Pandit H, et al. Adverse outcomes after total and unicompartmental knee replacement in 101,330 matched patients: a study of data from the National Joint Registry for England and Wales. Lancet. 2014 Oct 18; 384(9952):1437-45. Lombardi AV Jr, Berend KR, Walter CA, et al. Is recovery faster for mobile-bearing unicompartmental than total knee arthroplasty? Clin Orthop Relat Res. 2009 Jun; 467(6):1450-7. Lunebourg A, Parratte S, Ollivier M, et al. Are Revisions of Unicompartmental Knee Arthroplasties More Like a Primary or Revision TKA? J Arthroplasty. 2015 Nov; 30(11):1985-9. Lewold S, Robertsson O, Knutson K, et al. Revision of unicompartmental knee arthroplasty: outcome in 1,135 cases from the Swedish Knee Arthroplasty study. Acta Orthop Scand. 1998 Oct; 69(5):469-74. Hang JR, Stanford TE, Graves SE, et al. Outcome of revision of unicompartmental knee replacement. Acta Orthop. 2010 Feb; 81(1):95-8. Sawatari T, Tsumura H, Iesaka K, et al. Three-dimensional finite element analysis of unicompartmental knee arthroplasty--the influence of tibial component inclination. J Orthop Res. 2005 May; 23(3):549-54. Welch-Phillips A, Gibbons D, Ahern DP, et al. What Is Finite Element Analysis? Clin Spine Surg. 2020 Oct; 33(8):323-324. Thompson SM, Lindisfarne EA, Bradley N, et al. Periprosthetic supracondylar femoral fractures above a total knee replacement: compatibility guide for fixation with a retrograde intramedullary nail. J Arthroplasty. 2014 Aug; 29(8):1639-41. Geller JA, Yoon RS, Macaulay W. Unicompartmental knee arthroplasty: a controversial history and a rationale for contemporary resurgence. J Knee Surg. 2008 Jan; 21(1):7-14. Johal S, Nakano N, Baxter M,et al. Unicompartmental Knee Arthroplasty: The Past, Current Controversies, and Future Perspectives. J Knee Surg. 2018 Nov; 31(10):992-998. Gill J R, Corbett J A, Wastnedge E, et al Forgotten joint score: comparison between total and unicompartmental knee arthroplasty. The Knee. 2021; 29:26–32. Zhuang Z, Huang C, Chen X, et al. Prevalence of osteoporosis in patients awaiting unicompartmental knee arthroplasty: a cross-sectional study. Front Endocrinol (Lausanne). 2023 Sep 11; 14:1224890. Crist B D , Aggarwal A , Lewis C, et al.Materials and Biomechanics. 2015.DOI:10.1007/978-2-8178-0475-0_6. Choi S K , Alzahrani M , Gorguluarslan R. An elastic modulus adjustment method for implants having lattice scaffolds structure and patient specific surgical implants which use the method:KR20180095176[P].KR20190100837A[2024-09-25]. Kuromoto N K , Sato H H , Tiagovalerio D, et al.Elastic Modulus of Oxidized Ti‐Nb Alloys[C]//John Wiley & Sons, Ltd.John Wiley & Sons, Ltd, 2015. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6137782","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":436455983,"identity":"57c4ef30-5dcd-4ad9-87c6-b80eeb54c9db","order_by":0,"name":"Shuaixian 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12:37:12","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":10334,"visible":true,"origin":"","legend":"\u003cp\u003eCement Pile\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/d22d076f36dcab250a1ead02.jpg"},{"id":79678514,"identity":"206bbec7-92d4-4182-acf2-7fead658ac40","added_by":"auto","created_at":"2025-04-01 12:29:12","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":33280,"visible":true,"origin":"","legend":"\u003cp\u003eTibia and Fixed Platform Assembly \u0026nbsp;(a) Front View \u0026nbsp;(b) Top View\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/cc2a0ca3a1cf1fc6cd4ef416.jpg"},{"id":79678516,"identity":"7a1dbe0c-d042-410b-aa76-71182356f613","added_by":"auto","created_at":"2025-04-01 12:29:12","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":19229,"visible":true,"origin":"","legend":"\u003cp\u003eFixed Platform and Cement Pile Assembly\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/333da9c8ab44e9747f7ad872.jpg"},{"id":79680448,"identity":"96a22022-434b-42fc-a6fb-27d02f7324f4","added_by":"auto","created_at":"2025-04-01 12:45:12","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":65417,"visible":true,"origin":"","legend":"\u003cp\u003evon Mises stress cloud map of prosthetic tibial plateau (a)front view \u0026nbsp;without fixed column \u0026nbsp;(b) front view with fixed column (c) front view with fixed column+bone cement (d) top view without fixed column \u0026nbsp;(e) top view with fixed column (f) top view with fixed column+bone cement\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/59c896b8e1041fa912097412.jpg"},{"id":79679437,"identity":"d4786851-81e7-465d-8e96-d366a7f4cf90","added_by":"auto","created_at":"2025-04-01 12:37:12","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":50604,"visible":true,"origin":"","legend":"\u003cp\u003evon Mises stress cloud map of tibia (a) without fixed column, (b) with fixed column, (c) fixed column+bone cement\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/cb730bc50b593b0c14c25477.jpg"},{"id":79679445,"identity":"ce749907-58e7-4557-9a7a-60f3cb490fb5","added_by":"auto","created_at":"2025-04-01 12:37:12","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":48833,"visible":true,"origin":"","legend":"\u003cp\u003eCloud diagram of the first principal stress of the tibial plateau prosthesis (a) without fixed column, (b) with fixed column, (c) fixed column+bone cement\u003c/p\u003e","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/40198e6437c31489eb8a7d3e.jpg"},{"id":79678518,"identity":"e06f3845-d727-4968-8a4e-d0efac9b15dc","added_by":"auto","created_at":"2025-04-01 12:29:12","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":46798,"visible":true,"origin":"","legend":"\u003cp\u003eFirst principal stress cloud map of tibia (a) without fixed column, (b) with fixed column, (c) fixed column+bone cement\u003c/p\u003e","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/104ff1a635cddde4e2d7f992.jpg"},{"id":79679440,"identity":"2f9e1dd0-0a67-4310-9e41-e413834803bf","added_by":"auto","created_at":"2025-04-01 12:37:12","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":57419,"visible":true,"origin":"","legend":"\u003cp\u003eStrain cloud map of tibial plateau prosthesis (a) without fixed column, (b) with fixed column, (c) fixed column+bone cement\u003c/p\u003e","description":"","filename":"11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/240e2159ef755a1a5782ec73.jpg"},{"id":79678520,"identity":"2fa6074b-5437-4ca3-85a0-c9b09122e7db","added_by":"auto","created_at":"2025-04-01 12:29:12","extension":"jpg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":61047,"visible":true,"origin":"","legend":"\u003cp\u003eTibial strain cloud map \u0026nbsp;(a) without fixed column, (b) with fixed column, (c) fixed column+bone cement\u003c/p\u003e","description":"","filename":"12.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/7ad04b015da007692a42d011.jpg"},{"id":79680945,"identity":"ca00494b-0975-4258-8915-74540b199fed","added_by":"auto","created_at":"2025-04-01 12:53:12","extension":"jpg","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":59231,"visible":true,"origin":"","legend":"\u003cp\u003eOperation during surgery (a) deepening the fixed bolt hole of the tibia (b) deepening the depth of the fixed bolt hole of the tibia (Figure source: Intraoperative images taken by the author)\u003c/p\u003e","description":"","filename":"13.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/09361f1f75fc5db6f104e751.jpg"},{"id":79678539,"identity":"272b779e-6482-4a4a-9d22-4429a7f9590f","added_by":"auto","created_at":"2025-04-01 12:29:12","extension":"jpg","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":24958,"visible":true,"origin":"","legend":"\u003cp\u003eThe imaging data after surgery (a)orthopedic X-ray image after deepening the fixed bolt hole of the tibia, with the arrow indicating the deepened portion\u003c/p\u003e\n\u003cp\u003e(b) lateral X-ray image after deepening the fixed bolt hole of the tibia, with the arrow indicating the deepened part (Figure source: Postoperative X-ray taken by the author)\u003c/p\u003e","description":"","filename":"14.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/d66a5b21340994dcaf3b35b6.jpg"},{"id":80291592,"identity":"d5ac6eee-9a98-4509-bb0e-294d5419635a","added_by":"auto","created_at":"2025-04-10 08:02:10","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1038047,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6137782/v1/ae2c8715-3fd4-478d-8675-95ccb1cce9fd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Three-Dimensional Finite Element Analysis for the Stability of Tibial Plateau Prosthesis in Improved Unicompartmental Knee Arthroplasty","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eThe knee joint is the largest weight-bearing joint in the lower limbs of the human body and is prone to knee osteoarthritis (KOA)\u003csup\u003e[1]\u003c/sup\u003e. The main clinical manifestations of KOA are progressive degeneration of cartilage, narrowing of joint spaces compared to anatomical spaces, and formation of osteophytes around the knee joint, leading to joint pain and limited mobility\u003csup\u003e[2]\u003c/sup\u003e. Due to the physiological characteristics of the knee joint, degeneration of the medial meniscus is more common than that of the lateral meniscus, which can lead to an increase in pressure on the medial compartment joint cartilage and accelerate the development of medial compartment osteoarthritis in the knee joint\u003csup\u003e[3]\u003c/sup\u003e. The knee joint first undergoes knee inversion, which means that the load is more concentrated in the medial compartment. This inversion will lead to higher mechanical stress and inner wear \u003csup\u003e[4]\u003c/sup\u003e. Compared with the lateral compartment, the medial compartment of the knee bears higher compressive stress and contact pressure\u003csup\u003e[5]\u003c/sup\u003e. In a normally inverted knee, the medial compartment typically bears 60-70% of the total intrinsic compressive load\u003csup\u003e[6,7]\u003c/sup\u003e, while the medial meniscus bears greater pressure, making it more prone to tearing under severe load conditions. \u0026nbsp;Knee inversion further increases the load on the medial compartment. Research has shown that the pressure in the medial compartment increases significantly with the adjustment of varus\u003csup\u003e[8]\u003c/sup\u003e.This also explains why knee osteoarthritis is more common in the medial compartment of the knee joint. The degeneration of knee cartilage leads to varus deformity, further increasing the pressure in the medial compartment, resulting in a vicious cycle of aggravation of the medial knee joint bone joint, while other compartments are not affected. This also provides a theoretical basis for unicompartmental replacement surgery of the medial compartment of the knee joint. Compared to total knee arthroplasty, unicompartmental arthroplasty aims to maintain knee function and improve patient prognosis by only replacing the affected compartment. It is a knee conserving surgery that preserves bone mass and anterior and posterior cruciate ligaments, as well as the lateral compartment. It has the advantages of minimal trauma, less bleeding, shorter hospital stay, better proprioceptive and motor abilities, and good patient satisfaction\u003csup\u003e[9-12]\u003c/sup\u003e. However, it is accompanied by a high revision rate of unicompartmental replacement surgery, with a 5-year revision rate of 7% -15%\u003csup\u003e[13]\u003c/sup\u003e. The high revision rate of unicompartmental replacement is highly correlated with postoperative complications\u003csup\u003e[14.15]\u003c/sup\u003e, such as tibial periprosthetic fractures, tibial prosthesis collapse, polyethylene pad wear, and so on\u003csup\u003e[16]\u003c/sup\u003e. How to reduce postoperative complications and revision rates has become a hot topic at present. Therefore, after more than 400 cases of unicompartmental replacement surgery, we propose to make technical improvements to the knee unicompartmental replacement surgery. On the basis of the original tibial plateau prosthesis fixed column, we deepen the fixed column and build a bone cement column to increase the support and stability of the tibial plateau prosthesis.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThree-dimensional finite element analysis(3D FEA) is a computational method used to predict the behavior of materials in three-dimensional space under various forces. \u0026nbsp;In the field of orthopedics, this technology is valuable for designing and testing implants. It allows for a detailed analysis of the performance of implants in complex anatomical structures\u003csup\u003e[17]\u003c/sup\u003e. In medical applications, 3D FEA is used to create patient specific biomechanical models, enabling accurate analysis of stress distribution in tissues and organs. This is crucial for understanding the mechanical behavior of biological structures under load. 3D FEA has the advantage of creating physically accurate patient specific biomechanical models based on in vivo imaging data. It allows for precise calibration in complex environments through reverse analysis techniques, enabling the study of tissue stress and contact pressure distribution. 3D FEA is a powerful tool for evaluating the mechanical behavior and stability of these prostheses under various conditions. This analysis helps to understand the stress distribution, micro motion, and overall biomechanical performance of the prosthesis, which is crucial for optimizing design and surgical outcomes.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe aim of this study is to use finite element analysis to establish models of tibial plateau prosthesis without fixation, with fixed column, and with fixed column+bone cement column unicompartmental replacement surgery. By setting specific conditions to compare the stress and strain of the tibial plateau prosthesis and tibia in each model, the advantages and clinical feasibility of the improved technique of knee unicompartmental replacement surgery (deepening of tibial plateau prosthesis fixed column) are explored, providing reference and guidance for the technical improvement of clinical surgery.\u003c/p\u003e"},{"header":"2 Materials and Methods","content":"\u003cp\u003e2.1 Design the establishment and finite element analysis of models without fixed columns, with fixed columns, and with fixed columns and bone cement for medial knee joint fixation platform unicompartmental replacement surgery.\u003c/p\u003e\n\u003cp\u003e2.2 Materials\u003c/p\u003e\n\u003cp\u003e2.2.1 Software configuration\u003c/p\u003e\n\u003cp\u003eWorkbench 18.2, Mimics 20.0, Geomagic 2013, SOLIDWORKS 2017.\u003c/p\u003e\n\u003cp\u003eThe above software generated Figure 1-10.\u003c/p\u003e\n\u003cp\u003e2.2.2 Selection of prostheses\u003c/p\u003e\n\u003cp\u003eFixed platform unicompartmental prosthesis (Zimmer-Biomet, USA)\u003c/p\u003e\n\u003cp\u003e2.2.3\u003c/p\u003e\n\u003cp\u003eMaterial properties and contact conditions\u003c/p\u003e\n\u003cp\u003eAfter considering the contact conditions between the prosthesis and the tibia, the mechanical performance parameters of the titanium alloy material are shown in Table 1. Grid division is crucial for finite element analysis, directly affecting the accuracy and speed of the solution. The number of grids is shown in Table 2.\u003c/p\u003e\n\u003cp\u003eTable 1 Material Parameters\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eElastic modulus/GPa\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003ePoisson\u0026apos;s ratio\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eCortical bone\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e15\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e0.33\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eTrabecular bone\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e0.12\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e0.33\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eFixed platform\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e200\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e0.3\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eBone cement pile\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e2.1\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 2 Number of grids\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eNo fixed column\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eFixed column\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eFixed column + bone cement pile\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eCortical bone\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e369043\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e369043\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e369043\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eTrabecular bone\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e488102\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e488214\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e487324\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eFixed platform\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e35177\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e38344\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e38344\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eBone cement pile\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e1464*2\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003etotal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e892322\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e895601\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e897639\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e2.3 Methods\u003c/p\u003e\n\u003cp\u003e2.3.1 Boundary Conditions and Load Application\u003c/p\u003e\n\u003cp\u003eTo simulated the normal walking state under physiological load conditions, the load was applied to the joint surface, to replicate the actual stress environment. The distal end of the tibia and a portion of the shaft were removed while preserving the tibial plateau. To more closely restore the physiological structure of the knee joint, the fixed platform prosthesis was set at an angle of 5\u0026deg; with the horizontal plane. Fixed constraints were applied at the bottom of the model, fully constraining all directions of the bottom surface. A vertical load of 1000N was applied to the upper surface of the tibia to simulate the physiological load at the knee joint when a normal adult stands on both feet. Based on the physiological distribution, the load was evenly distributed with 60% on the medial platform and 40% on the lateral platform of the tibia, to simulate the physiological state as closely as possible. The boundary conditions are shown in Figure 1. The boundary conditions were consistent across all three scenarios.\u003c/p\u003e\n\u003cp\u003e2.3.2 Model Establishment\u003c/p\u003e\n\u003cp\u003eA three-dimensional model of a fixed platform unicompartmental prosthesis and tibia was established using the computer-aided design software Workbench 18.2. \u0026nbsp; The tibial model was reconstructed based on medical imaging data, utilizing titanium alloy as the prosthetic material (Figure 2 to 6).\u003c/p\u003e"},{"header":"3 Results","content":"\u003cp\u003e3.1 von Mises stress\u003c/p\u003e\n\u003cp\u003eVon Mises stress is a critical parameter for evaluating the deformation behavior of materials under composite stress states.Represents the equivalent stress in three-dimensional situations where materials are subjected to a combination of normal stress (tension or compression) and shear stress (shear force in different directions). By calculating von Mises stress, complex stress states can be simplified into a single value, facilitating the evaluation of material strength and stability.\u003c/p\u003e\n\u003cp\u003eThe positions of the maximum and minimum values were consistent across the three cases. Compared with the first two cases, the von Mises stress in the tibia was minimized when a bone cement pile was present. (Figures 7 and 8).\u003c/p\u003e\n\u003cp\u003e3.2 First principal stress\u003c/p\u003e\n\u003cp\u003eThe first principal stress indicates the direction and magnitude of the maximum normal stress that occurs in a material under a composite stress state. It represents the maximum tensile or compressive stress in a specific direction within the material, providing crucial information for designing and evaluating the safety of structures. By analyzing the first principal stress, the bearing capacity of the material in a specific direction can be determined to ensure that the structure does not exceed its ultimate strength under actual usage conditions.\u003c/p\u003e\n\u003cp\u003eThe first principal stress was minimized when a bone cement pile was present under the fixed column of the fixed platform(Figures 9 and 10).\u003c/p\u003e\n\u003cp\u003e3.3 Strain\u003c/p\u003e\n\u003cp\u003eStrain refers to the degree of deformation of a material under external loading or deformation. It describes the relative displacement and deformation within the material. By analyzing strain, the degree of deformation and distortion of materials under specific loads or loading conditions can be determined, thereby evaluating the stability, safety, and performance of the structure.\u003c/p\u003e\n\u003cp\u003eThe tibial strain was minimized when a bone cement pile was present under the fixed platform column(Figures 11 and 12).\u003c/p\u003e"},{"header":"4 Application in surgery","content":"\u003cp\u003eBased on the aforementioned results, the surgical technique was applied by drilling two fixed bolt holes in the temporary fixed platform mold and deepening the two fixed bolt holes of the tibia using a bone hammer and the tail end of a footstool (Figure 13). \u0026nbsp;The postoperative imaging data are shown in Figure 14.\u003c/p\u003e"},{"header":"5 Discussions","content":"\u003cp\u003eUnicompartmental knee arthroplasty(UKA), also known as unicompartmental arthroplasty, is primarily used to treat knee arthritis, especially in patients with severe cartilage wear or joint deformities\u003csup\u003e[18]\u003c/sup\u003e. In the early 1950s, McKeever first proposed the concept that osteoarthritis could be confined to a specific compartment in the knee joint and subsequently implanted the first unicompartmental knee prosthesis in 1952\u003csup\u003e[19]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eIn 1968, Gunston developed a multi center knee prosthesis that more accurately replicated knee joint kinematics while preserving the cruciate ligament. The Oxford femoral prosthesis, first used in 1982, consisted of a spherical joint surface femoral prosthesis and a flat tibial prosthesis. An unconstrained high-density polyethylene \u0026quot;meniscus\u0026quot; bearing, which conformed to the metal component and was maintained \u0026nbsp;by its shape and soft tissue tension, was inserted between the two components. This design was adjusted in 1987 to lower the anterior lip of the meniscus bearing to prevent it from extending onto the femur. The third generation Oxford UKA was launched in 1998, featuring includes a larger size range and instrumentation designed \u0026nbsp;for minimally invasive surgery\u003csup\u003e[20]\u003c/sup\u003e. UKA is one of the methods for treating unicompartmental knee inflammation, which involves replacing the damaged area to alleviate knee pain and improve patients\u0026apos; daily living abilities.\u003c/p\u003e\n\u003cp\u003eWith the improvement of unicompartmental technology and continuous optimization of prosthesis design, UKA has garnered significant interest as an effective treatment for knee arthritis, with advantages such as a wide range of motion, better physical sensation, and high postoperative scores\u003csup\u003e[21]\u003c/sup\u003e. However, its high revision rate and complications, including postoperative prosthesis loosening, periprosthetic fractures, and tibial plateau collapse, cannot be overlooked. Knee osteoarthritis patients often suffer from osteoporosis, which has been shown to be related to complications such as postoperative prosthesis loosening, fractures around the prosthesis, and collapse of the tibial plateau\u003csup\u003e[22]\u003c/sup\u003e. With the increasing aging population in China, minimizing complications while preserving the benefits of UKA has become a focal point of current research. Therefore, we proposed improvements to the UKA surgical technique and validated their significance through 3D FEA.\u003c/p\u003e\n\u003cp\u003eDuring UKA surgery, after inserting a temporary bone plate (tibial plateau trial) for tibial fixation, a conventional gun drill was used to drill bolt holes. Subsequently, a foot pedal and bone hammer were used to deepen the drilling column from its original height of 6.85mm to 10mm. After fully filling the space with bone cement, the tibial plateau prosthesis was placed, and the area beneath the fixation column was filled with bone cement to form a bone cement column. Using finite element analysis software, we established models of knee joint medial fixed platform unicompartmental replacement surgery without fixed columns, with fixed columns, and with fixed columns and bone cement columns. Based on the load distribution ratio of the medial and lateral compartments of the knee joint, we assumed that the medial compartment bears 60% of the normal standing knee joint pressure load under human physiological conditions. By setting specific boundary conditions, we simulated and analyzed the knee joint unicompartmental replacement surgery model as closely as possible to real conditions. The finite element analysis results demonstrated that when a bone cement pile was present under the fixed platform column, the von Mises stress, first principal stress, and strain of the tibia were lower than in the other two scenarios. Platforms with bone cement piles exhibited better mechanical properties under various load conditions, resulting in less tibial deformation. This finding strongly supports the evaluation of one of the key factors for surgical success: the stability of the prosthesis and bone.\u003c/p\u003e\n\u003cp\u003eIn orthopedics, the elastic modulus is often used to describe material stiffness. Compared with tibial plateau prostheses, cortical bone has a lower hardness\u003csup\u003e[23]\u003c/sup\u003e. The elastic modulus is a key parameter in biomechanics, defining a materials ability to deform under stress and recover its original shape after stress relief. The introduction of a tibial plateau prosthesis creates a significant difference in elastic modulus at the prosthesis-bone interface, leading to the stress shielding effect\u003csup\u003e[24.25]\u003c/sup\u003e. Some scholars have investigated special treatments and adjustments of tibial plateau prostheses to reduce the elastic modulus at the contact surface with bone tissue, matching it as closely as possible to minimize the stress shielding effect and ensure the long-term success of prosthesis implantation\u003csup\u003e[25]\u003c/sup\u003e. Similarly, this study deepened the hole under the original tibial plateau fixation column and filled it with bone cement, creating a whole and form a lower elastic modulus at the bone contact surface. Compared with the large difference in elastic modulus caused by direct contact between the original fixation column and cancellous bone, this approach plays an intermediate transitional role and enhances biomechanical compatibility. Additionally, we proposed the \u0026quot;column\u0026quot; theory, which likens the deepening of the fixed column of the tibial plateau prosthesis to deepening the foundation of a house. The deeper the foundation, the more stable the structure, thereby increasing the support and stability of the tibial plateau prosthesis in UKA surgery.\u003c/p\u003e\n\u003cp\u003eAlthough 3D FEA largely simulates the physiological state of bone structure, it still has limitations and cannot exclude interference from muscles and other unpredictable factors. It also cannot directly represent clinical results. However, this study provides valuable information for clinical surgical techniques and lays a theoretical foundation for future clinical experiments. Further research is needed to determine whether the advantages of this improved surgical technique can be applied to obese and osteoporotic patients. Future studies can optimize material selection, prosthesis design, and surgical techniques to enhance the effectiveness of artificial joint replacement surgery.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNot applicable.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eS.T. and J.W. and Y.Z. wrote the main manuscript text. J.L. and Z.L. prepared figure 13 and 14. Z.L.have drafted the work and substantively revised it. S.T. and J.W. and Y.Z. contributed equally as co-first authors. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data generated or analysed during this study are included in this published article.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eHuman Ethics and Consent to Participate declarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGBD 2015 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016 Oct 8;388(10053):1545-1602.\u003c/li\u003e\n\u003cli\u003eCasta\u0026ntilde;eda S, Roman-Blas JA, Largo R, et al. Osteoarthritis: a progressive disease with changing phenotypes. Rheumatology (Oxford). 2014 Jan;53(1):1-3.\u003c/li\u003e\n\u003cli\u003eYadav S K, Shirol V S, Chavan R, et al. Microscopic Structural Changes in Osteoarthritic Menisci of the Human Knee Joint. Journal of the Scientific Society. 2022, 49(3): 310-317.\u003c/li\u003e\n\u003cli\u003eRussell EM, Miller RH, Umberger BR, et al. Lateral wedges alter mediolateral load distributions at the knee joint in obese individuals. J Orthop Res. 2013 May;31(5):665-71.\u003c/li\u003e\n\u003cli\u003eDevaraj A K , Acharya K K V , Adhikari R .Comparison of Biomechanical Parameters between Medial and Lateral Compartments of Human Knee Joints.Bentham Science Publishers B.V. 2020(1).\u003c/li\u003e\n\u003cli\u003ePutnis S, Neri T, Parker D. Outcomes of Surgery for Medial Arthrosis. Osteotomy About the Knee: A Comprehensive Guide. 2020: 47-63.\u003c/li\u003e\n\u003cli\u003eM\u0026oslash; lgaard C M, Kersting U G. The effect of shoe design and lateral wedging on knee loading[M]//Proc. Of Int. Society of Biomech. XXIII. Brussels, Belgium. 2011.\u003c/li\u003e\n\u003cli\u003eWillinger L, Lang JJ, Berthold D, et al. Varus alignment aggravates tibiofemoral contact pressure rise after sequential medial meniscus resection. Knee Surg Sports Traumatol Arthrosc. 2020 Apr; 28(4):1055-1063.\u003c/li\u003e\n\u003cli\u003eLim JW, Cousins GR, Clift BA,et al. Oxford unicompartmental knee arthroplasty versus age and gender matched total knee arthroplasty - functional outcome and survivorship analysis. J Arthroplasty. 2014 Sep; 29(9):1779-83.\u003c/li\u003e\n\u003cli\u003eNewman J, Pydisetty RV, Ackroyd C. Unicompartmental or total knee replacement: the 15-year results of a prospective randomised controlled trial. J Bone Joint Surg Br. 2009 Jan; 91(1):52-7.\u003c/li\u003e\n\u003cli\u003eLiddle AD, Judge A, Pandit H, et al. Adverse outcomes after total and unicompartmental knee replacement in 101,330 matched patients: a study of data from the National Joint Registry for England and Wales. Lancet. 2014 Oct 18; 384(9952):1437-45.\u003c/li\u003e\n\u003cli\u003eLombardi AV Jr, Berend KR, Walter CA, et al. Is recovery faster for mobile-bearing unicompartmental than total knee arthroplasty? Clin Orthop Relat Res. 2009 Jun; 467(6):1450-7.\u003c/li\u003e\n\u003cli\u003eLunebourg A, Parratte S, Ollivier M, et al. Are Revisions of Unicompartmental Knee Arthroplasties More Like a Primary or Revision TKA? J Arthroplasty. 2015 Nov; 30(11):1985-9.\u003c/li\u003e\n\u003cli\u003eLewold S, Robertsson O, Knutson K, et al. Revision of unicompartmental knee arthroplasty: outcome in 1,135 cases from the Swedish Knee Arthroplasty study. Acta Orthop Scand. 1998 Oct; 69(5):469-74.\u003c/li\u003e\n\u003cli\u003eHang JR, Stanford TE, Graves SE, et al. Outcome of revision of unicompartmental knee replacement. Acta Orthop. 2010 Feb; 81(1):95-8.\u003c/li\u003e\n\u003cli\u003eSawatari T, Tsumura H, Iesaka K, et al. Three-dimensional finite element analysis of unicompartmental knee arthroplasty--the influence of tibial component inclination. J Orthop Res. 2005 May; 23(3):549-54.\u003c/li\u003e\n\u003cli\u003eWelch-Phillips A, Gibbons D, Ahern DP, et al. What Is Finite Element Analysis? Clin Spine Surg. 2020 Oct; 33(8):323-324.\u003c/li\u003e\n\u003cli\u003eThompson SM, Lindisfarne EA, Bradley N, et al. Periprosthetic supracondylar femoral fractures above a total knee replacement: compatibility guide for fixation with a retrograde intramedullary nail. J Arthroplasty. 2014 Aug; 29(8):1639-41.\u003c/li\u003e\n\u003cli\u003eGeller JA, Yoon RS, Macaulay W. Unicompartmental knee arthroplasty: a controversial history and a rationale for contemporary resurgence. J Knee Surg. 2008 Jan; 21(1):7-14.\u003c/li\u003e\n\u003cli\u003eJohal S, Nakano N, Baxter M,et al. Unicompartmental Knee Arthroplasty: The Past, Current Controversies, and Future Perspectives. J Knee Surg. 2018 Nov; 31(10):992-998.\u003c/li\u003e\n\u003cli\u003eGill J R, Corbett J A, Wastnedge E, et al Forgotten joint score: comparison between total and unicompartmental knee arthroplasty. The Knee. 2021; 29:26\u0026ndash;32.\u003c/li\u003e\n\u003cli\u003eZhuang Z, Huang C, Chen X, et al. Prevalence of osteoporosis in patients awaiting unicompartmental knee arthroplasty: a cross-sectional study. Front Endocrinol (Lausanne). 2023 Sep 11; 14:1224890.\u003c/li\u003e\n\u003cli\u003eCrist B D , Aggarwal A , Lewis C, et al.Materials and Biomechanics. 2015.DOI:10.1007/978-2-8178-0475-0_6.\u003c/li\u003e\n\u003cli\u003eChoi S K , Alzahrani M , Gorguluarslan R. An elastic modulus adjustment method for implants having lattice scaffolds structure and patient specific surgical implants which use the method:KR20180095176[P].KR20190100837A[2024-09-25].\u003c/li\u003e\n\u003cli\u003eKuromoto N K , Sato H H , Tiagovalerio D, et al.Elastic Modulus of Oxidized Ti‐Nb Alloys[C]//John Wiley \u0026amp; Sons, Ltd.John Wiley \u0026amp; Sons, Ltd, 2015.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"knee osteoarthritis, Fixed platform, Unicompartmental replacement, Biomechanics, Finite element analysis, Technological improvement","lastPublishedDoi":"10.21203/rs.3.rs-6137782/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6137782/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe primary treatment for end-stage unicompartmental knee osteoarthritis is unicompartmental knee arthroplasty. Reducing postoperative complications following unicompartmental knee arthroplasty has become a focal point of current research.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eThis study aimed to investigate the effects of stress magnitude and distribution on the tibial plateau prosthesis and tibial structure after conventional medial knee arthroplasty and modified surgery using finite element analysis. By comparing the two surgical methods, the advantages and feasibility of the modified surgery were evaluated.\u003c/p\u003e\u003ch2\u003eMethod\u003c/h2\u003e \u003cp\u003eModels of unicompartmental knee arthroplasty with a fixed platform were constructed using Workbench 18.2 software, including models without fixed columns, models with fixed columns, and models with fixed columns and bone cement. To restore the normal physiological structure of the knee joint to a greater extent, the posterior inclination angle of the tibial fixation platform prosthesis was set to 5\u0026deg;. A vertical downward load of 1000 N was applied to the center of the tibial surface of the three models. The stress data of the tibial fixation platform prosthesis and the tibia under the prosthesis were observed and compared in each model.\u003c/p\u003e\u003ch2\u003eResult\u003c/h2\u003e \u003cp\u003eWhen there is a cement pile under the fixed platform column, the von Mises stress, first principal stress, and strain of the tibia are all lower than the other two cases. Therefore, the tibia with bone cement piles has less deformation and is more stable under stress compared to the other two structures of the tibia.\u003c/p\u003e","manuscriptTitle":"A Three-Dimensional Finite Element Analysis for the Stability of Tibial Plateau Prosthesis in Improved Unicompartmental Knee Arthroplasty","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-01 12:29:07","doi":"10.21203/rs.3.rs-6137782/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d59601d3-06d3-40da-930d-fd83a692597c","owner":[],"postedDate":"April 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":46471768,"name":"Health sciences/Diseases"},{"id":46471769,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2025-04-10T07:54:02+00:00","versionOfRecord":[],"versionCreatedAt":"2025-04-01 12:29:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6137782","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6137782","identity":"rs-6137782","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}