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The plaster-casting method to create a scoliosis brace consists of mould generation and rectification to obtain the desired orthosis geometry. Alternative methods entail the use of 3D scanning and CAD/CAM. However, both manual and digital design entirely rely on the orthotist expertise. Characterisation of the rectification process is needed to ensure that digital designs are as efficient as plaster-cast designs. Three-dimensional scans of five patients, pre-, and post-rectification plaster moulds were obtained using a Structure Mark II scanner. Anatomical landmark positions, transverse section centroids, and 3D surface deviation analyses were performed to characterise the rectification process. The rectification process was characterised using two parameters. First, trends in the external contours of the rectified moulds were found, resulting in lateral tilt angles of 81 ± 3.8° and 83.3 ± 2.6° on the convex and concave side, respectively. Second, a rectification ratio at the iliac crest (0.23 ± 0.04 and 0.11 ± 0.02 on the convex and concave side, respectively) was devised, based on the pelvis width to estimate the volume to be removed. This study demonstrates that steps of the manual rectification process can be characterised. Results from this study can be fed into software to perform automatic digital rectification.

External fixation is a commonly used method in stabilizing fracture sites. The performance of the fixator depends on how it affects the mechanical properties of the fracture site and is governed by parameters like the fixator type and fixator configuration. Identifying ideal configurations prior to surgery will help surgeons in planning the procedure, limiting the possibility of complications such as non-union. In this study, a framework has been proposed as a surgical pre-planning tool, to assist surgeons compare mechanical properties of a fracture site under different fixator configurations, and thereby identify the optimum solution. A computational tool was identified as the best method for this purpose. Cost and time of computation were given special consideration to reduce complexity in clinical settings. A pilot study was conducted on a section of the proposed framework, where the aim was to understand the feasibility of implementation. In the pilot study, a unilateral uni-planar fixator on a simple diaphyseal transverse fracture was analyzed. During the pilot study the selected fixator was tested and a few models were developed to assess system stability. The models were then compared to identify the optimum model that could be used with the proposed framework. The proposed framework provided a suitable solution for the use case and out of the models developed the simplified finite element model was identified as the best option for the use case.