A practical guide to image processing in the creation of 3D models for orthopedics

Three-dimensional (3D) computer modelling and 3D printing technology is approaching a commodity level in many areas, including medical applications. 3D computer models are used in a wide variety of these applications, such as preoperative planning and patient-specific customized implants in orthopedics that treat complex fractures and correct pathologic anatomy. This article provides a detailed description of the processes involved in creating and printing a 3D anatomic model. In addition, the various steps associated with the imaging of anatomic injuries or deformities using computed tomographic or magnetic resonance imaging scanners, image processing and segmentation techniques, the creation of a virtual 3D model, printer selection for 3D printing of the model, and hardware and software requirements are discussed. An example of a case in which a 3D printed model was used as a preoperative planning tool is provided to demonstrate the procedures involved from start to finish, culminating in a 3D printed anatomic model.