Evaluation of the Safety, Feasibility, and Early Clinical Outcomes of Patient-Specific Bone Defect Implants Fabricated From Titanium Alloy (Ti-6Al-4V) Using 3D Printing Technology

The goal of this clinical trial is to evaluate the safety and feasibility of patient-specific bone defect implants fabricated from Ti-6Al-4V using 3D printing technology and to assess early clinical outcomes within the first 12 months following implantation of these customized devices. The main question it aims to answer is: "In patients with bone defects requiring surgical reconstruction, are patient-specific bone defect implants fabricated from titanium alloy (Ti-6Al-4V) using 3D printing technology - designed and produced at VinUni, safe and feasible for clinical use, and do they result in favorable early clinical outcomes within the first 12 months following implantation?"

Bone defects resulting from trauma, tumor resection, infection, or congenital abnormalities represent a significant clinical burden in orthopedic and reconstructive surgery worldwide. Large or complex bone defects often lead to prolonged disability, functional impairment, and reduced quality of life if not appropriately treated. According to the World Health Organization (WHO), each year there are approximately 20-50 million non-fatal road traffic injuries globally, many of which are associated with fractures and segmental bone loss requiring surgical intervention.1 In addition, age-related musculoskeletal disorders such as osteoporosis, which affects an estimated 200 million people worldwide, further increase the incidence of bone defects and fracture-related complications.2 Epidemiological studies have shown that bone loss following tumor resection, severe trauma, or chronic infection remains a major challenge due to limited regenerative capacity and high mechanical demands at defect sites. Traditional reconstruction methods, including autologous and allogeneic bone grafting, although widely applied, are associated with several limitations such as donor-site morbidity, limited graft availability, risk of infection transmission, prolonged treatment time, and difficulty in achieving optimal anatomical reconstruction.3,4 As a result, bone reconstruction using artificial implantable materials has emerged as a promising therapeutic strategy. Among available options, artificial bone implants based on metallic biomaterials, particularly titanium alloys, have gained increasing attention due to their ability to provide immediate mechanical stability and support biological integration.5-7 Titanium and titanium-based alloys have been extensively used in clinical bone implantation for several decades and are recognized as among the most reliable materials for skeletal reconstruction.5,7 These materials have demonstrated favorable mechanical strength, corrosion resistance, and excellent biocompatibility, allowing long-term implantation in the human body. Titanium implants have been successfully applied in a wide range of clinical settings, including cranial and craniofacial reconstruction, limb and long bone defect replacement, spinal fixation, and dental implantation.5 Regulatory authorities such as the U.S. Food and Drug Administration (FDA) have approved the use of titanium alloys, including Ti-6Al-4V, for implantable medical devices based on accumulated evidence of safety and effectiveness.6 Furthermore, international standards such as ISO 5832 and ISO 10993, and also Vietnamese national standard clearly define requirements for chemical composition, mechanical properties, and biocompatibility testing of titanium alloys used in medical implants.8-10 Numerous international and domestic studies have consistently reported low toxicity, minimal inflammatory response, and good osseointegration associated with titanium-based implants, thereby confirming their trial.show_full_description

Inclusion Criteria: * Diagnosed with a bone defect requiring surgical reconstruction, as determined by the treating orthopedic surgeon * Suitable candidate for implantation of a patient-specific device manufactured from Ti-6Al-4V * Able to undergo preoperative imaging (CT ± MRI) required for implant design * Willing and able to provide written informed consent * Willing to comply with scheduled follow-up visits and study assessments Exclusion Criteria: * Active systemic or local infection at the surgical site at the time of implantation * Known hypersensitivity or allergy to titanium or titanium alloys * Severe uncontrolled comorbidities that significantly increase surgical risk (e.g., uncontrolled diabetes, severe cardiovascular disease) * Pregnant or breastfeeding women * Participation in another interventional clinical study that may interfere with the outcomes of this study * Inability to complete follow-up assessments within the required timeframe