In this paper, an open data format for three-dimensional surgical planning of total hip arthroplasty based on XML is described. We design an XML (eXtensible Markup Language) format to save position and orientation of the implants, references to the 3D images and surface models, anatomical coordinate system, joint coordinate system for motion analysis, and quantitative evaluation results for planning. The main feature of the proposed method is an embedded script for generating drilled bone models at the client planning system. The embedded script reduces an amount of transfer data from the planning server as compared with generating the drilled bone models at the planning server and transferring them. In order to evaluate the usability of the XML data format, we implemented a client-server system for remote browsing of 3D planning. We applied the proposed system to five cases (three planning datasets for each) and compared the total time of transfer and processing for visualization of planning datasets between by the server-side model generating system and by the client-side model generating system with embedded script. In secondary and thirdly received planning dataset in each case, the total time of the client-side system was shorter than that of the server-side system. The results showed a potential usefulness of the proposed XML data format which embedding the script.
