The application of Three-dimensional printing on foot fractures and deformities: A mini-review

Reconstruction of the Talus and Calcaneus Using a Three-Dimensional (3D)-Printed Custom Implant Following a Shotgun Wound: A Case Report

We present a case detailing the successful reconstruction of the hindfoot in a 15-year-old male patient who suffered a self-inflicted shotgun wound. The patient had multiple complex fractures in these bones, resulting in considerable bone loss and the destruction of the articular surface. Considering the extent of the injuries and the failure of prior intervention from an outside surgeon, traditional reconstruction methods would not have adequately addressed the severity of the damage. Consequently, the treating physician opted to address the deformity using a three-dimensional (3D)-printed custom implant to salvage the limb. The treatment involved a two-stage surgical plan. The first stage encompassed debridement with the removal of antibiotic cement, which had been placed at the time of the initial injury, followed by debridement and placement of a new temporary antibiotic spacer. A 21-day course of antibiotics was administered to combat the developing osteomyelitis. Following the successful eradication of the infection, a second surgery entailed removing the spacer and residual bone, inserting the 3D-printed implant filled with bone graft, and fusing the hindfoot. Post-surgery, the patient steadily progressed from non-weight-bearing to full weight-bearing and was fully weight-bearing at five months post-surgery. He had reported significant improvements in pain and mobility. There were no complications, and the 3D-printed implant exhibited excellent integration with the surrounding bone tissue with a two-year follow-up. This case serves as a demonstration of the utility of 3D-printed custom implants in severe foot and ankle trauma, showcasing the technology's potential to revolutionize orthopedic surgery. Despite the potential risks, this approach highlights significant benefits and opens avenues for tailored reconstructions in complex orthopedic injuries.

Response surface methodology and machine learning based tensile strength prediction in ultrasonic assisted coating of poly lactic acid bone plates manufactured using fused deposition modeling

Poly Lactic Acid (PLA) based bone plates fabricated using Fused Deposition Modeling have poor mechanical strength which can be improved by biocompatible polydopamine (PDM) coating. However, PDM particles, being heavy in nature, settle at the container bottom with increase in coating solution concentration at the time of bone plate coating using dip coating technique. Thus, the present work aims to witness the effect of ultrasonic assisted coating parameters on tensile strength of coated bone plates. The coating parameters involving power of ultrasonic vibrations, coating solution concentration and immersion time were varied. The standard Response Surface Methodology (RSM) was applied and experimental trials were performed for obtaining tensile strength of bone plates under varied coating parameters. The objective of the present study was to compare the values of tensile strength predicted using RSM and machine learning (ML) models. Based on the obtained experimental values, gradient boosting regression (GBReg), linear regression (LReg) and random forest regression (RFReg) were trained and tested for predicting tensile strength of bone plates. The accuracy and prediction errors corresponding to RSM and ML based models were compared with respect to R2, Mean Squared Error (MSE), Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE). The findings revealed that GBReg exhibited R2, MSE, RMSE and MAE values as 0.9312, 1.7142, 1.2877 and 1.0861 respectively, while RSM showed R2, MSE, RMSE and MAE values as 0.882, 2.13, 1.4595 and 1.258 respectively. RSM model has shown minimum accuracy with high prediction errors amongst the four models. GBReg has outperformed other ML models in terms of their accuracy and error metrics. The present study therefore suggests the application of GBReg based ML model for predicting tensile strength of PDM coated bone plates in response to its accurate and robust prediction performance.

Polymer/Graphene Nanocomposites via 3D and 4D Printing—Design and Technical Potential

Graphene is an important nanocarbon nanofiller for polymeric matrices. The polymer–graphene nanocomposites, obtained through facile fabrication methods, possess significant electrical–thermal–mechanical and physical properties for technical purposes. To overcome challenges of polymer–graphene nanocomposite processing and high performance, advanced fabrication strategies have been applied to design the next-generation materials–devices. This revolutionary review basically offers a fundamental sketch of graphene, polymer–graphene nanocomposite and three-dimensional (3D) and four-dimensional (4D) printing techniques. The main focus of the article is to portray the impact of 3D and 4D printing techniques in the field of polymer–graphene nanocomposites. Polymeric matrices, such as polyamide, polycaprolactone, polyethylene, poly(lactic acid), etc. with graphene, have been processed using 3D or 4D printing technologies. The 3D and 4D printing employ various cutting-edge processes and offer engineering opportunities to meet the manufacturing demands of the nanomaterials. The 3D printing methods used for graphene nanocomposites include direct ink writing, selective laser sintering, stereolithography, fused deposition modeling and other approaches. Thermally stable poly(lactic acid)–graphene oxide nanocomposites have been processed using a direct ink printing technique. The 3D-printed poly(methyl methacrylate)–graphene have been printed using stereolithography and additive manufacturing techniques. The printed poly(methyl methacrylate)–graphene nanocomposites revealed enhanced morphological, mechanical and biological properties. The polyethylene–graphene nanocomposites processed by fused diffusion modeling have superior thermal conductivity, strength, modulus and radiation- shielding features. The poly(lactic acid)–graphene nanocomposites have been processed using a number of 3D printing approaches, including fused deposition modeling, stereolithography, etc., resulting in unique honeycomb morphology, high surface temperature, surface resistivity, glass transition temperature and linear thermal coefficient. The 4D printing has been applied on acrylonitrile-butadiene-styrene, poly(lactic acid) and thermosetting matrices with graphene nanofiller. Stereolithography-based 4D-printed polymer–graphene nanomaterials have revealed complex shape-changing nanostructures having high resolution. These materials have high temperature stability and high performance for technical applications. Consequently, the 3D- or 4D-printed polymer–graphene nanocomposites revealed technical applications in high temperature relevance, photovoltaics, sensing, energy storage and other technical fields. In short, this paper has reviewed the background of 3D and 4D printing, graphene-based nanocomposite fabrication using 3D–4D printing, development in printing technologies and applications of 3D–4D printing.

Smart 3D Printed Hydrogel Skin Wound Bandages: A Review

Wounds are a major health concern affecting the lives of millions of people. Some wounds may pass a threshold diameter to become unrecoverable by themselves. These wounds become chronic and may even lead to mortality. Recently, 3D printing technology, in association with biocompatible hydrogels, has emerged as a promising platform for developing smart wound dressings, overcoming several challenges. 3D printed wound dressings can be loaded with a variety of items, such as antibiotics, antibacterial nanoparticles, and other drugs that can accelerate wound healing rate. 3D printing is computerized, allowing each level of the printed part to be fully controlled in situ to produce the dressings desired. In this review, recent developments in hydrogel-based wound dressings made using 3D printing are covered. The most common biosensors integrated with 3D printed hydrogels for wound dressing applications are comprehensively discussed. Fundamental challenges for 3D printing and future prospects are highlighted. Additionally, some related nanomaterial-based hydrogels are recommended for future consideration.