Novel Positioning Feedback System as a Guidance in Bone Tumor Resection

Need: Bone resection using customized 3D-printed guides can improve accuracy, but the technique is still associated with clinically significant errors. Technical solution: We developed an inexpensive optical feedback system (OFS) that compares intraoperative 2D camera images to the pre-operative plan, and accurately depicts the surgeon's guide placement prior to cutting, reducing the errors in resection. Proof of concept: We simulated wide resections of a bone sarcoma on 24 cadaver femurs using 3 cutting guide types. Guide placement was measured using the OFS and compared to CT-scans showing the actual guide position. We carried out a second, controlled study on 20 sawbones, comparing the accuracy of the final bone cuts with and without the surgeon actively using the OFS to adjust the guide position before cutting. Results: For cadavers, in 2 of 3 planes, the position of the jig recorded by the OFS closely matched its actual position, with an accuracy of .87 degrees +/- .65 degrees(r = .94) and 1.2 degrees +/- 1.3 degrees(r = .81) in the transverse and sagittal planes, respectively. In the second study, OFS increased accuracy of the final cut about the transverse and sagittal planes, respectively by 53.1% (P = .011)/54.7% (P = .04) and 33% (P = .051)/38% (P = .042) in terms of rotation and translation. Next steps: Developing the OFS as a mobile application to reduce the processing time and improve accessibility in the operating room. Conclusion: The OFS could accurately depict the guide placement on the bone and significantly improve the surgical accuracy of 3D printed jigs.

Automated summary

The use of an inexpensive optical feedback system (OFS) can accurately depict the placement of surgical guides and significantly improve the accuracy of 3D printed jigs.