Surgical treatment of complex deformities necessitates a detailed appreciation of the complex three dimensional abnormal anatomies involved. Preoperative planning for these complex cases traditionally involves x-ray and computerised tomography (CT). These modalities offer only two-dimensional images to represent three-dimensional anatomy. Advances in digital imaging have allowed three-dimensional reconstructions to be derived from CT images. These greatly improve understanding of complex deformities, but will never be able to replace the intuitive understanding that is gained by handling a physical model.

The Rapid Prototyping technique Selective Laser Sintering (SLS) is used in the industrial setting to manufacture prototype models from Computer Aided Designs (CAD). This technology can be utilised to convert CT images into accurate three-dimensional physical models of the human bony anatomy.

We present the use of SLS modelling to aid in the preoperative planning of complex reconstructive surgery in children. Cases include bladder exstrophy, developmental dysplasia of the hip and reconstruction of a complex elbow malunion.

The models provide invaluable visual and tactile information to the operating surgeon, accurately demonstrating the abnormal anatomy in an easily comprehensible manner. They allow estimation of the magnitude and degree of corrections necessary and evaluation of bony deficiencies.

Aim: Advances in digital imaging have allowed three dimensional reconstructions to be derived from CT images which greatly improve understanding of complex deformities. Selective laser sintering (SLS) is used in the industrial setting to manufacture prototype models from Computer Aided Designs (CAD). This technology can be utilised to convert CT images into accurate three dimensional physical models of the human bony anatomy. This SLS modelling was used as an aid in the pre-operative planning of complex pelvic surgery.

Materials and Methods: Standard pre-operative X-ray of the pelvis and a CT scan was undertaken. Using MIMICS software and selective laser sintering, models of these deformities could be made. The cases included bladder exstrophy and a complex developmental dysplasia of the hip with associated femoral head dislocation. The cost of this was comparable with a CT scan or MRI scan.

Conclusion: These models provide invaluable visual and tactile information to the operating surgeon, accurately demonstrating the abnormal anatomy in an easily comprehensible manner. They allow estimation of the magnitude and degree of corrections necessary and evaluation of bony deficiencies.