# Morphometric Analysis and Three-Dimensional Computed Tomography Reconstruction of Thai Distal Femur
## 1 Introduction  
The largest bone in the human body is a femur, which is widely researched in fields such as forensic anthropology and orthopedics. For forensic anthropology research, the femur's morphology, both proximal and distal parts, was investigated to determine differences in the femur concerning populations and sex [1,2]. The orthopedics research involvesan analysis of the proximal femur, including a femoral head, neck, and the proximal femoral medullary canal for hip joint studies [2; 3; 4]. The dimensions of the distal femur are important, especially in the prostheses or implants design for a knee joint such as total knee arthroplasty (TKA) [5; 6; 7]. Generally, the femur's morphometric studies could be conducted by direct measurements based on a dry bone using Vernier calipers or rulers [8; 9; 10; 11]. Alternatively, the indirect method was performed using a reversed engineering technique based on the data from radiography, computed tomography scans (CT), and magnetic resonance imaging (MRI). The advantage of this method is the investigation in a digital format that is non-destructive of the specimen, and the useful assessment identified anatomical landmarks and included the automatically calculated measurement [12]. Computed tomography data can be measured in both two-dimensional (2D) and three-dimensional (3D) formats [13; 14; 15; 16]. Based on three-dimensional measurement, the femoral 3D models were created by a reverse engineering technique, which involves returning the physical product to virtual models that can be considered as two phases, including a digitization and reconstruction phase. The digitization phase relates data acquisition from physical objects, a sample part or prototype, using various forms of a scanner. The data from scanning have been collected as images or a 3D coordinates representation of the object's surface (point cloud data). Then, in the reconstruction phase, the data are transferred to Computer-Aided Reverse Engineering (CARE) software for the reconstruction of the three-dimensional model in which the surface is represented as a polygonal mesh [3; 17; 18; 19; 20]. In addition, the morphological evaluation based on 3D models is an adequate accurate dimension and convenient measurement. Moreover, the models can be configured such as rotation, translation, and clipping [21; 22]. There are several studies featuring the morphometric analysis of Thai femoral such as a study of morphological parameters of the proximal femur with a three-dimensional measurement technique [4], a measurement of the anteroposterior and mediolateral length of distal femur based on MRI [23], and intraoperative anthropometric measurement of resected Thai distal femurs during surgery [24]. However, a morphometric study of the Thai distal femur has reported some parameters that may be insufficient for the application, such as the sexual prediction in forensic science or knee prosthesis design. For the design of the knee implant, the dimension of implant geometry is one factor that affects the durability of the prostheses. The optimization of the implant dimension coverage surface area between bone and implant component is one approach to improving the longevity of the prostheses because it can reduce stress around the bone and wear in the tibial insert [25]. In addition, the biomechanics of the knee joint should be considered in the designing process of the knee implant. Finite Element Analysis (FEA), the process of simulating the behavior of a physical problem using a numerical mathematic technique, is the method that is used to analyze the biomechanics of various knee prosthesis designs [26]. This method allows the modeling of complex geometry and system of loads such as forces, pressure, and movement that corresponding to activities in daily life. Therefore, FEM can be efficient in simulating various situations to improve the design of various implants [25; 27; 28]. This study aims to provide only fundamental morphometric data of the Thai distal femur.