Innovative knee implant design for different materials and optimisation by finite element method

Total knee arthroplasty (TKA) has been used for more than 50 years to treat chronic degenerative conditions of the knee. One of the most economical and consistently successful orthopedic procedures is total knee arthroplasty (TKA). Total knee arthroplasty (TKA) is a procedure that relieves knee pain by replacing the majority of damaged tissue within the knee joint with a prosthetic implant. Implants are only used in cases of severe knee joint injuries, excessive deformations or degenerative diseases such as osteoarthritis. All these diseases cause patients to experience more or less severe pain, discomfort and restricted limb movement. After the implant, the patient can resume normal daily activities, which relieves the pain. Through targeted reflex therapy and recovery exercises, mobility is restored during the procedure. TKA has led to reproducible, durable and effective improvements in patients, as evidenced by outcomes such as reduced pain and improved overall quality of life. In addition to reviewing the indications, risks and procedures of total knee replacement, this exercise plays an important role in the health of patients with knee arthritis. However, with regard to pain reduction, functional improvement and better quality of life, patientreported outcomes have been shown to be significantly improved. The use of knee implants is one of the options used in the surgical treatment of knee conditions that reduce the quality of life, such as osteoarthritis (calcification of the knee due to trauma), sedentary lifestyle, increased fat content in the body that affects health, cartilage damage, wear and tear of the knee due to cartilage loss, and the inability to perform bending movements, which is one of the main functions of the joint. To anticipate implant life and foresee potential issues, prosthetic behavior and qualities must be studied before being implanted into a human body. An embed's composition may alter, however it is typically made of biocompatible substances like plastic, ceramics, or metal alloys. The affected person's needs can also influence the implant's design. Due to improper bone resectioning, defective implant component design, and implant component wear and tear over time, instability at the knee implants and subsequent stages following TKA are all brought on by these factors. Similar to this, faulty surgical techniques, inaccurate fabrication of implant components, inappropriate implant selection, joint loosening, and patients' pre-existing anatomical flaws all contribute to the misalignment of knee implants. Bone cement may be used during total knee replacement to fill the area between the prosthesis and bone. When applying cement, installing a prosthesis, loosening a tourniquet, or decreasing a joint, a condition known as cement embolism or bone cement implantation syndrome can cause hypoxia and/or hypotension as well as cardiac mortality. The real incidence of this issue is unknown, however it is still uncertain if it is uncommon or underdiagnosed. Devices such as knee implants and prostheses are designs that are the result of collaboration between engineers, orthopaedic specialists and surgeons. This interdisciplinary collaboration increases the success rate of the application. Research into new materials and the development of new technologies are accelerating these processes. Research is constantly being conducted to create implants that are fully biocompatible, do not cause side effects such as allergic, anti-bacterial and resistant to external influences. In recent years, significant research has been conducted into the interactions between biomaterials and tissues, as well as the use of biocompatible materials to reconstruct the body's natural tissues. In the present, there is an increase in patients suffering from arthritis or other injuries brought on by accidents or sports, which has led to an increase in the number of patients undergoing arthroplasty surgery. As a result, a sizable number of patients may choose a revision surgical procedure. The materials to be applied to form the knee implant must be biocompatible, meaning they must be able to function as intended within the body without triggering a reaction that would cause the body to reject them. Due to their interaction with the surrounding tissues and environment, biomaterials do manufacture or release microscopic particles that cause the blood to develop free radical ions, which in turn causes inflammation in the affected area. Due to the fact that only a small number of microscopic particles are emitted, only a few biomaterials are examined and used in the medical industry. However, the particular requirements of the implant's material to be utilized vary, and must be established by the patient's condition, the structural makeup of the joint, and the surgical procedure that will be applied. In knee replacement surgery, damaged or worn knee joint components are replaced with artificial implants. Metal, ceramic and plastic materials are used to make artificial implants. They are used to improve the functionality of the knee, reduce pain and improve the patient's quality of life. Depending on how the implant is used, the parts that come into contact with each other will wear out, and if the wear exceeds a certain limit, the implant will need to be replaced. Most knee replacements can be used for 15 to 20 years. This is obviously inadequate in today's environment where life expectancy is continually rising. For instance, a patient who has a total hip replacement at age 50 can require one or two reoperations throughout the course of their lifespan. It's crucial for maintaining knee health after a prosthesis to avoid actions that put strain on the knee, refrain from running unless absolutely essential, and maintain a healthy weight. This dissertation aims to design an artificial knee implant to solve knee joint problems caused by the patient's health status, age, gender, weight, etc. In these situations, the final model created must be a lifelike model customized for each patient due to the complexity of the geometric design of any three-compartment knee prosthesis and the specificity of the particular dimensions of the components. In this way, when designing the implant model, the design size and geometric harmony should be determined by taking into account individual features such as anatomy and physiology. One of the most important steps during implant design is the creation of a CAD design based on the patient's anatomical measurements. The advantage of the method is that the model can be applied to a large number of patients by simply changing the design dimensions. The study aims to use Computer Aided Design (CAD) and Computer Aided Analysis (CAE) methods. The designs were done in SolidWorks software and the analyses were done in ANSYS WorkBench software. After the CAD model was created, analyses were performed using ANSYS WorkBench software and then optimisation was performed using the finite element approach. During the designs, artificial knee implant models with 5 different wall thicknesses and 4 different materials (PE, UHMWPE, PEEK, PMMA) were considered and the changes that occur on the implant under the influence of different pressure values were analysed using the finite element (FEM) method. As a result, the optimum wall thickness, material and pressure value for the designed artificial knee implant model were optimised using the finite element method. In addition, the most suitable knee implant was determined by cost comparison. Furthermore, the side effects that occur after the application of the examined materials to the body were also examined. The biomaterials considered to be used for the production of knee implants, as well as their basic properties, benefits, disadvantages, application conditions and postoperative complications that may occur depending on such situations are determined.