Custom plate

Abstract: Bone plates for the fixation of complex fractures in proximity to joints often have to be reshaped to follow the bone contour. Good adhesion of the screws in areas where the bone is osteoporotic is also a challenge. One possible solution to these issues is to tailor-make plates by creating a digital three-dimensional model of the fracture from a computed tomography (CT) scan, digitally reducing the fracture, designing a plate, and finally manufacturing it directly from the digital model with solid free-form fabrication (SFF) technology. This study designs a custom plate for a distal tibia fracture, and investigates and refines the procedure from the CT scan to the final implant, with the aim of making it usable in trauma orthopaedics. The bone plate is manufactured using electron beam melting (EBM) technology. The challenges of bone plate design using digitalization and SFF are discussed. The virtual models created by the engineer while digitally reducing the fracture and modeling the plate are valuable for the physician while planning the surgery. A combination of surgery planning and digital plate design improves the surgeon's preparations and ensures correspondence between the plan and the designed implant. The proposed procedure, with the approximate required time in brackets, includes the separation of bone in the DICOM file (60 min), the reduction of fracture (5-30 min), revision (30 min), modelling of the plate (30-120 min), confirmation (30 min), manufacturing with SFF (10 h), post-processing (60 min), and finally cleaning and sterilization (90 min). The whole procedure requires about three working days.

Abstract: The high cost of commercially available force plates instrumented to quantify postural sway can be prohibitive to both research and clinical institutions. Therefore custom plate design and construction within the institutional environment is not uncommon. Some plate designs, however, may give erroneous measurements depending upon subject position. We report here on the existence of a kern boundary on the plate surface. Loads placed inside this boundary result in support compression, while those placed outside cause at least one support to experience tension. The findings indicate that the type of force transducer used for corner support (unidirectional or bidirectional), the type of connection between the plate and transducers, plate weight, subject weight, plate dimensions and transducer preloads are all critical to accurate measurements.

Abstract: Fractures of the orbit often require operative repair with materials ranging from autologous tissue to titanium implants. Reconstructive techniques of the lateral orbital rim and wall offer a unique challenge due to the structural and aesthetic demands with regard to its natural contour. The authors present a case in which a patient sustained a ballistic injury involving the lateral orbital rim and wall requiring reconstruction. The authors employed the use of a single titanium orbital mesh fan plate (DePuy Synthes, Warsaw IN) in an injury-specific and cost-effective technique to rapidly restore the contour and structure of the lateral orbit rivaling the result of a 3D printed custom plate.

Abstract: The present study proposes an integrated computer-aided approach combining femur surface modeling, fracture evidence recover plate creation, and plate modification in order to conduct a parametric investigation of the design of custom plate for a specific patient. The study allows for improving the design efficiency of specific plates on the patients’ femur parameters and the fracture information. Furthermore, the present approach will lead to exploration of plate modification and optimization. The three-dimensional (3D) surface model of a detailed femur and the corresponding fixation plate were represented with high-level feature parameters, and the shape of the specific plate was recursively modified in order to obtain the optimal plate for a specific patient. The proposed approach was tested and verified on a case study, and it could be helpful for orthopedic surgeons to design and modify the plate in order to fit the specific femur anatomy and the fracture information.