Accuracy Validation in Image - Guided Orthopaedic Surgery

Validating the accuracy of image-guided surgical systems is a challenging and important problem which has received little attention in the literature. Potential sources of inaccuracy include: CT imaging noise, model generation errors, errors introduced by fixturing, intra-operative data noise, registration errors, and inaccuracies in surgical tools and actions. In this paper, we discuss our experience in validating an example image-guided application in orthopaedic surgery. Various sources of inaccuracy are identified and approaches for mitigating their effects are suggested. The difficult problem of generating a reliable ground-truth for evaluating the accuracy of surgical registration is discussed, and surface-based registration accuracy results are presented. A fiducial marker design which can be used to establish highly accurate ground-truth correspondence between pre-and intra-operative data is offered. Finally, the need for better accuracy met-rics in image-guided surgery is noted, and shortcomings of metrics which are commonly used in the literature are illustrated .