Custom-Made 3D-Printed Implants as Novel Approach to Reconstructive Surgery after Oncologic Resection in Pediatric Patients

Surgical Outcomes and Complications of Custom-Made Prostheses in Upper Limb Oncological Reconstruction: A Systematic Review

Bone tumors of the upper limb are a common cause of bone pain and pathological fractures in both old and young populations. Surgical reconstruction and limb salvage have become valid options for these patients despite this kind of surgery being challenging due to the need for wide bone resection and the involvement of surrounding soft tissues. Computer-assisted technology helps the surgeon in pre-operative planning and in designing customized implants. The aim of this study was to investigate the surgical outcomes and complications of custom-made prostheses in oncologic reconstruction of the upper limb and if they are reliable options for patients suffering from aggressive tumors. An electronic search on PubMed, Google Scholar, and Web of Knowledge was conducted to identify all available articles on the use of custom-made prostheses in oncological resections of the upper limb. Twenty-one studies were included in the review, comprising a total of 145 patients with a mean age of 33.68 years. The bone involved was the humerus in 93 patients, and the radius was involved in 36 patients. There were only six cases involving proximal ulna, three cases involving the scapula, and seven cases involving the elbow as well as soft tissues around it. The most frequent primary tumor was the giant cell tumor, with 36 cases, followed by osteosarcoma with 25 cases, Ewing Sarcoma with 17 cases, and Chondrosarcoma with 7 total cases. Forty patients were affected by bone metastases (such as renal cell cancer, breast cancer, melanoma, and rectal cancer) or hematologic diseases involving bone (lymphoma, myeloma, or non-Hodgkin disease). Custom-made prostheses are a viable option for patients who suffer from malignant tumors in their upper limbs. They are a reliable aid for surgeons in cases of extensive resections.

3D printing in pediatric surgery

Pediatric surgery presents a unique challenge, requiring a specialized approach due to the intricacies of compact anatomy and the presence of distinct congenital features in young patients. Surgeons are tasked with making decisions that not only address immediate concerns but also consider the evolving needs of children as they grow. The advent of three-dimensional (3D) printing has emerged as a valuable tool to facilitate a personalized medical approach. This paper starts by outlining the basics of 3D modeling and printing. We then delve into the transformative role of 3D printing in pediatric surgery, elucidating its applications, benefits, and challenges. The paper concludes by envisioning the future prospects of 3D printing, foreseeing advancements in personalized treatment approaches, improved patient outcomes, and the continued evolution of this technology as an indispensable asset in the pediatric surgical arena.

Biological Prosthesis (Hollow 3D-Printed Titanium Custom-Made Prosthesis and Bone Graft) for Humeral Reconstruction in Pediatric Oncologic Patients: Surgical Indications and Results

This study presents the mid-term outcomes of a novel "biological prosthesis" for pediatric humerus reconstruction after major bone tumor removal. This approach involves a hollow 3D-printed titanium custom-made prosthesis combined with bone grafting. The primary aim was to preserve and revitalize the unaffected autologous proximal or distal humeral stump. Between 2017 and 2021, we treated five pediatric patients (mean age 11.2 years; range 7-17) with humeral bone sarcomas. A one-stage surgical procedure involved tumor resection and implanting a hollow 3D-printed custom-made prosthesis. In two cases, we preserved the proximal humerus; in two, the distal part; and in one, both. Graft materials included homologous bone chips in three cases and free vascularized fibular grafts in two cases. All patients were clinically and radiographically assessed after a mean follow-up of 32.2 months (range of 14-68). No significant complications were observed, and no implant revisions were needed. Osseointegration was evident in all cases within eight months post-surgery; vascular support for the remaining autologous stump was demonstrated in all cases. Our hollow 3D-printed custom-made prosthesis and bone grafting offer the potential for partial or complete articular surface preservation. This approach encourages revascularization of the epiphysis, leading to satisfactory outcomes in humerus reconstruction within the pediatric population.

A new patient-specific overformed anatomical implant design method to reconstruct dysplastic femur trochlea

Patellar luxation with condylar defect is a challenging situation for reconstruction in humans. Patella reluxation, cartilage damage and pain are the most common complications. This study aims to present a new patient specific method of overformed implant design and clinical implantation that prevents luxation of patella without damaging the cartilage in a dog. Design processes are Computer Tomography, Computer Assisted Design, rapid prototyping of the bone replica, creation of the implant with surgeon's haptic knowledge on the bone replica, 3D printing of the implant and clinical application. The implant was fully seated on the bone. Patella reluxation or implant-related bone problem was not observed 80 days after the operation. However, before the implant application, there were soft tissue problems due to previous surgeries. Three-point bending test and finite element analysis were performed to determine the biomechanical safety of the implant. The stress acting on the implant was below the biomechanical limits of the implant. More cases with long-term follow-up are needed to confirm the success of this method in patellar luxation. Compared with trochlear sulcoplasty and total knee replacement, there was no cartilage damage done by surgeons with this method, and the implant keeps the patella functionally in sulcus. This is a promising multidisciplinary method that can be applied to any part of the bone and can solve some orthopaedic problems with surgeon's haptic knowledge.

Application of 3-dimensional printing implants for bone tumors

Three-dimensional (3D) additive manufacturing has recently been used in various medical fields. Among them, orthopedic oncology is one that utilizes it most actively. Bone and tumor modeling for surgical planning, personalized surgical instrument fabrication, and implant fabrication are typical applications. The 3D-printed metal implants using titanium alloy powder have created a revolutionary change in bone reconstruction that can be customized to all body areas; however, bioprinting remains experimental and under active study. This review explores the practical applications of 3D printing in orthopedic oncology and presents a representative case. The 3D-printed implant can replace the conventional tumor prosthesis and auto/allobone graft, thereby personalizing bone reconstruction. Biologic bone reconstruction using biodegradable or bioprinted materials beyond metal may be possible in the future.

Three-dimensional-printed titanium prostheses with bone trabeculae enable mechanical-biological reconstruction after resection of bone tumours

Reconstruction after resection has always been an urgent problem in the treatment of bone tumours. There are many methods that can be used to reconstruct bone defects; however, there are also many complications, and it is difficult to develop a safe and effective reconstruction plan for the treatment of bone tumours. With the rapid development of digital orthopaedics, three-dimensional printing technology can solve this problem. The three-dimensional printing of personalised prostheses has many advantages. It can be used to print complex structures that are difficult to fabricate using traditional processes and overcome the problems of stress shielding and low biological activity of conventional prostheses. In this study, 12 patients with bone tumours were selected as research subjects, and based on individualised reverse-engineering design technology, a three-dimensional model of each prosthesis was designed and installed using medical image data. Ti6Al4V was used as the raw material to prepare the prostheses, which were used to repair bone defects after surgical resection. The operation time was 266.43 ± 21.08 minutes (range 180-390 minutes), and intraoperative blood loss was 857.26 ± 84.28 mL (range 800-2500 mL). One patient had delayed wound healing after surgery, but all patients survived without local tumour recurrence, and no tumour metastasis was found. No aseptic loosening or structural fracture of the prosthesis, and no non-mechanical prosthesis failure caused by infection, tumour recurrence, or progression was observed. The Musculo-Skeletal Tumour Society (MSTS) score of limb function was 22.53 ± 2.09 (range 16-26), and ten of the 12 patients scored ≥ 20 and were able to function normally. The results showed that three-dimensional printed prostheses with an individualised design can achieve satisfactory short-term clinical efficacy in the reconstruction of large bone defects after bone tumour resection.

The Role of 3D Printing in Planning Complex Medical Procedures and Training of Medical Professionals-Cross-Sectional Multispecialty Review

Medicine is a rapidly-evolving discipline, with progress picking up pace with each passing decade. This constant evolution results in the introduction of new tools and methods, which in turn occasionally leads to paradigm shifts across the affected medical fields. The following review attempts to showcase how 3D printing has begun to reshape and improve processes across various medical specialties and where it has the potential to make a significant impact. The current state-of-the-art, as well as real-life clinical applications of 3D printing, are reflected in the perspectives of specialists practicing in the selected disciplines, with a focus on pre-procedural planning, simulation (rehearsal) of non-routine procedures, and on medical education and training. A review of the latest multidisciplinary literature on the subject offers a general summary of the advances enabled by 3D printing. Numerous advantages and applications were found, such as gaining better insight into patient-specific anatomy, better pre-operative planning, mock simulated surgeries, simulation-based training and education, development of surgical guides and other tools, patient-specific implants, bioprinted organs or structures, and counseling of patients. It was evident that pre-procedural planning and rehearsing of unusual or difficult procedures and training of medical professionals in these procedures are extremely useful and transformative.