Three-dimensional (3D) printing has developed as a revolutionary technology in surgical planning, prosthetic manufacturing, tissue engineering, and resident and medical student education. The technology allows to obtain an accurate design and manufacturing of physical models from medical imaging for patient-specific perioperative planning, and allows surgeons to perform complex reconstructions with high degrees of efficiency and quality.
The ability to create patient-specific models for use in the operating room permit the precise and rapid contouring of vascularized bone flaps.
The use of home-based 3D printing has become possible with the increasing availability and decreasing cost of 3D printing software and printers. Computed aided design (CAD) software is widely available and easy to use for home 3D printing systems. According to our knowledge few studies describe use of 3D printing with a in hospital-based 3D printer and no studies describe the use of 3D printing in the design of vascularized bone flaps for tibial reconstruction. The aim of this project is to evaluate the efficacy in using home 3D printing technology for fibular bone transfer in lower limb reconstruction after tibial resection due to osteomyelitis or tibial bone defect after acute trauma.
The reconstruction of large bone defects caused by trauma, disease or tumor resection is a fundamental challenge for orthopedic and plastic surgeons. Their critical size exceeds the intrinsic capacity of self-regeneration and consequently bone repair is delayed and impaired. This type of lesion is termed non-union bone fracture and requires additional treatment with bone graft materials in order to restore pre-existing function. Successful bone augmentation procedures should include an osteoconductive scaffold with sufficient mechanical stability, an osteo-inductive stimulus to induce osteogenesis, and should enable osseointegration and vascularity. The currently available treatment strategies of bone loss are based on autologous, allogeneic or xenogeneic bone transplantation, as well as synthetic biomaterials. Although autologous bone grafting still represents the gold standard technique for large bone reconstruction, several factors limit its application. A major restricting parameter is the volume of bone needed to treat this type of injury, as well as the associated pain and possible donor site complications due to the additional surgical intervention at the bone harvest site. Similar disadvantages may be observed for allogenic bone grafts including immunogenic reactions and transfer of diseases. Furthermore, many of these standard clinical grafting approaches fail due to the lack of adequate vascularization. Insufficient vascularity of the fracture site reduces the exchange of gas, nutrients and waste between the tissue and the blood system, as well as the delivery of cells to the site of injury, leading to inner graft necrosis. To circumvent this problem, vascularized bone transfers represent an excellent option that ensures bone vitality and avoids graft resorption. The use of vascularized bone flaps has become the gold standard for tibial reconstruction. The fibula flap is the workhorse flap for tibial reconstruction due to its thickness, length, and bone uniformity. However, the greatest challenges that remains is how to most accurately shape vascularized bone flaps minimizing the operative time of such complex surgery in the same time. Complex fractures and their reconstructions require modeling of the transferred bone to adapt to the anatomical shape which is time consuming. During conventional fibular free flap reconstruction of tibial defects, surgeons have to wait the end of the resection time to perform the fibular osteotomy and also spend a lot of time in modelling the flap prior to transfer. The last point increases the time of ischemia which is critical for flap survival. The success of a microsurgical procedure is highly related with the length of the surgical procedure.
Virtual surgical planning and 3D printing technologies has changed the way of bony reconstruction in recent years. This technique gave improved results in terms of reduced operating time and good aesthetic and functional results. 3D printing templates which can be used as a guide during bone resection and modeling of bone free flap for reconstruction.
Different studies exist in literature regarding the use of 3D printing for mandibular reconstruction after tumor resection with bone flap. Seruya et al. reported significantly decreased flap ischemia time, from 170 to 120 minutes in a series of 10 computer-assisted mandibular reconstructions; these results are confirmed by several studies in literature. Another benefit described is the improvement of accuracy in mandibular bone reconstruction. The cutting guides used for mandibular and fibular osteotomies and pre-bent titanium plates provided a faithful duplication of the preoperative virtual plan which allowed the surgeons to assemble the fibular segments into the defect of mandible as preoperative design and minimize the adjustments for the final inset compared to conventional method. There are no studies in literature regarding the use of these technologies for planning and guide tibial reconstruction with fibular flap.
The aim of this project is to optimize the technique of tibial bone reconstruction with fibular flap (which is now the gold standard for the treatment of extensive defect) using virtual surgical planning and 3D printing template. The purpose is to demonstrate how this technologies is able to optimize the fibular free flap harvest by performing an accurate preoperative planning, directing during surgery the site of osteotomy and modelling the flap for the precise in-setting at the level of tibial defect; the capacity of accurately reproducing the bone structure and defect could led to a better functional outcome reducing the risk of bone non-union and also sparing, if not necessary, the quantity of bone flap harvested at the donor site. The precise preoperative planning should led to a reduction of the surgical time and intraoperative/post-operative complication related and costs for the socio-sanitary system.