Introduction: Computer navigation and customized 3D-printed jigs improve accuracy during bone tumor resection, but such technologies can be bulky, costly, and require intraoperative radiation, or long lead time to be ready in OR. Methods: We developed a method utilizing a compact, inexpensive, non-X-ray based 3D surface light scanner to provide a visual aid that helps surgeons accurately draw osteotomy lines on the surface of exposed bone to reproduce a well-defined preoperative bone resection plan. We tested the accuracy of the method on 18 sawbones using a distal femur hemimetaphyseal resection model and compared it with a traditional, freehand method. Results: The method significantly reduces the positional error from 2.53 (± 1.13) mm to 1.04 (± 0.43) mm (p< 0.001), and angular error of the front angle from 2.10° (± 0.83°) to 0.80° (± 0.66°) (p=0.001). The method also reduces the mean maximum deviation of the bone resection, with respect to the preoperative path, from 3.75mm to 2.69mm (p=0.003). However, no increased accuracy was observed at the back side of the bone surface where this method would not be expected to provide information. Discussion: In summary, we developed a novel 3D-LAD navigation technology. From the experimental study, we demonstrated that the method can improve the ability of surgeons to accurately draw the preoperative osteotomy lines and perform resection of a primary bone sarcoma, with comparison to traditional methods, using 18 sawbones.

Tracking of the position and orientation of a moving object by a camera can be accomplished by attaching a 2D marker with a specific pattern on the object. Recently, we have developed a projection-based surgical navigation system that can accurately guide in real-time the pre-operative plan of resection in orthopedic surgery, such as joint replacement or wide-resection of osteosarcoma (bone tumor). To this end, it is important to study the accuracy of registration and tracking due to various sources of errors, such as the printing resolution and quality of the 2D marker. In this study, we investigate and provide analysis of error and uncertainty for real-time tracking using a 2D marker with a camera. Experiments and computational simulations were conducted to quantify the estimation of errors in position and orientation due to the printing error of 2D markers using a 600-dpi laser printer. In addition, a theory of uncertainty propagation in a form of congruence transformation was derived for such systems and is illustrated with experimental results.