The present work presents evaluation and experimental verification of the use of X-ray computed tomographic microscopy (micro-CT) for accurate characterization of geometry, microarchitecture, and stiffness properties of bones. These properties are crucial for designing and building optimized implants for joint and dental reconstruction applications. High-resolution micro-CT scans would provide more detailed and accurate information about the microarchitecture and density distribution across patient bones. Nevertheless, micro-CT applications on live patients require invasive procedures involving small bone biopsy specimens. Alternatively, micro-CT could be used on samples collected from selected cadavers of different age, gender, and race groups to establish a database that could be used for providing useful microarchitecture information. The micro-CT scans of investigated bone samples reveal that the trabecular bone is anisotropic and heterogeneous. The results also showed considerable degree of parametric variability and uncertainty on microarchitecture and stiffness properties of patient’s trabecular bone.

The present paper presents an integrated computer-aided engineering (CAE) approach combining digital imaging, solid modeling, robust design methodology, and finite element analysis in order to conduct a parametric investigation of the design of locked plating systems. The present study allows for understanding the contributions of different design parameters on the biomechanics and reliability of these systems. Furthermore, the present approach will lead to exploration of optimum design parameters that will result in robust system performance. Three-dimensional surface models of cortical and cancellous femoral bone were derived via digital computed tomography (CT) image processing techniques and a medical imaging analysis program. A nine orthogonal array matrix simulation (L9) was conducted using finite element methods to study the effects of the various design parameters on plate performance. The introduced technique was demonstrated and experimentally verified on a case study using a Smith & Nephew PERI- LOC distal femur locking plate and a Synthes Less Invasive Stabilization System (LISS).

In this paper, a method for robust design of a neural network (NN) model for prediction of delamination (Da), damage width (Dw), and hole surface roughness (Ra) during drilling in carbon fiber reinforced epoxy (BMS 8‐256) is presented. This method is based on a parametric analysis of neural network models using a design of experiments approach. The effects of number of neurons (N), hidden layers (L), activation function (AF), and learning algorithm (LA) on the mean square error (MSE) of model prediction are quantified. Using the aforementioned method, a robust NN model was developed that predicted process‐induced damage with high accuracy.

Existing implants used with Total Knee Arthroplasty (TKA), Total Hip Arthroplasty (THA), and other joint reconstruction treatments, have displayed premature failures and frequent needs for revision surgery in recent years, particularly with young active patients who represent more than 55% of all joint reconstruction patients. Bone cement and stress shielding have been identified as the major reasons for premature joint failures. A breakdown of the cement may happen, and revision surgery may be needed because of the aseptic loosening. The significant mismatch of stiffness properties of patient trabecular bones and metallic implant materials in joint reconstruction surgery results in the stress shielding phenomenon. This could lead to significant bone resorption and increased risk of bone fracture and the aseptic loosening of implants. The present project introduces an approach for development of customized cellular structures to match the mechanical properties and architecture of human trabecular bone. The present work aims at fulfilling the objectives of the introduced approach by exploring new designs of customized lattice structures and texture tailored to mimic closely patients’ bone anisotropic properties and that can incorporate an engineered biological press-fit fixation technique. The effects of various lattice design variables on the mechanical performance of the structure are examined through a systematic experimental plan using the statistical design of experiments technique and analysis of variance method. All tested lattice designs were explored under realistic geometrical, biological, and manufacturing constraints. Of the four design factors examined in this study, strut thickness was found to have the highest percent contribution (41%) regarding the structure stiffness, followed by unit cell type, and cell size. Strut shape was found to have the lowest effect with only 11% contribution. The introduced solution offers lattice structure designs that can be adjusted to match bone stiffness distribution and promote bone ingrowth and hence eliminating the phenomenon of stress shielding while incorporating biological press-fit fixation technique.