There has been a lot of hype surrounding the advantages to be gained from rapid prototyping processes in a number of fields, including medicine. Our literature review aims objectively to assess how effective patient-specific surgical guides manufactured using rapid prototyping are in a number of orthopaedic surgical applications. To this end, we carried out a systematic review to identify and analyse clinical and experimental literature studies in which rapid prototyping patient-specific surgical guides are used, focusing especially on those that entail quantifiable outcomes and, at the same time, providing details on the guides' design and type of manufacturing process. Here, it should be mentioned that in this field there are not yet medium- or long-term data, and no information on revisions. In the reviewed studies, the reported positive opinions on the use of rapid prototyping patient-specific surgical guides relate to the following main advantages: reduction in operating times, low costs and improvements in the accuracy of surgical interventions thanks to guides' personalisation. However, disadvantages and sources of errors which can cause patient-specific surgical guide failures are as well discussed by authors. Stereolithography is the main rapid prototyping process employed in these applications although fused deposition modelling or selective laser sintering processes can also satisfy the requirements of these applications in terms of material properties, manufacturing accuracy and construction time. Another of our findings was that individualised drill guides for spinal surgery are currently the favourite candidates for manufacture using rapid prototyping. Other emerging applications relate to complex orthopaedic surgery of the extremities: the forearm and foot. Several procedures such as osteotomies for radius malunions or tarsal coalition could become standard, thanks to the significant assistance provided by rapid prototyping patient-specific surgical guides in planning and performing such operations.

This paper is a systematic review of the literature on 3D-printed anatomical replicas used as templates for precontouring the fixation plates in orthopedic surgery. Embase, PubMed, Cochrane, Scopus and Springer databases were consulted for information on design study, fracture anatomical location, number of patients, surgical technique, virtual modeling approach and 3D printing process. The initial search provided a total of 496 records. After removing the duplicates, the title and abstract screening, and applying exclusion criteria and citations searching, 30 papers were declared eligible and included in the final synthesis. Seven studies were identified as focusing on retrospective non-randomized series of clinical cases, while two papers presented randomized case control studies. Two main approaches were highlighted in developing 3D-printed anatomical models for precontouring fixation plates: (a.) medical reconstruction, virtual planning and fracture reduction followed by 3D printing the model; (b.) medical reconstruction followed by 3D printing the model of the mirrored uninjured side. Revised studies reported advantages such as surgical time and blood loss reduction, while the reduction quality is similar with that of the conventional surgery. During the last couple of years there was an increase in the number of studies focused on precontouring orthopedic plates using 3D printing technology. Three-dimensionally-printed templates for plate precontouring were mostly used for acetabular fractures. Knowledge on medical virtual modeling and reconstruction is mandatory.

Purpose This paper aims to propose a new solution for producing customized three-dimensional (3D)-printed flat-shaped splints, which are then thermoformed to fit the patient’s hand. The splint design process is automated and is available to clinicians through an online application. Design/methodology/approach Patient anthropometric data measured by clinicians are associated with variables of parametric 3D splint models. Once these variables are input by clinicians in the online app, customized stereo lithography (STL) files for both splint and half mold, in the case of the bi-material splint, are automatically generated and become available for download. Bi-materials splints are produced by a hybrid manufacturing process involving 3D printing and overmolding. Findings This approach eliminates the need for 3D CAD-proficient clinicians, allows fast generation of customized splints, generates two-dimensional (2D) drawings of splints for verifying shape and dimensions before 3D printing and generates the STL files. Automation reduces splint design time and cost, while manufacturing time is diminished by 3D printing the splint in a flat position. Practical implications The app could be used in clinical practice. It meets the demands of mass customization using 3D printing in a field where individualization is mandatory. The solution is scalable – it can be extended to other splint designs or to other limbs. 3D-printed tailored splints can offer improved wearing comfort and aesthetic appearance, while maintaining hand immobilization, allowing visually controlled follow-up for edema and rapidly observing the need for revision if necessary. Originality/value An online application was developed for uploading patient measurements and downloading 2D drawings and STL files of customized splints. Different models of splints can be designed and included in the database as alternative variants. A method for producing bi-materials flat splints combining soft and rigid polymers represents another novelty of the research.

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