Improving Cutting Path on Custom 3D-Printed Surgical Guides for Bone-Tumor Resection

Custom three-dimensional (3D) printed guides are being used in the operative room as an aid to surgeons for increasing the accuracy of their cutting and resection techniques. In terms of bone-tumor resection, the cutting path printed in the custom jig is significantly important for two main purposes: first, the required fit for the implant that will replace the resected bone section and, second, the interaction between the remaining, healthy bone and the new implant in terms of forces, stresses and deformation. Bone tumor resection has posed a challenge in orthopedic oncology, specifically due to a high level of difficulty in performing a limb-sparing surgery with negative margins on the remaining bone. A straight cutting path is usually used in clinical procedures due to the type of tooling available inside the operative room. 3D printed cutting path guides offer the possibility to evolve from a straight to a different path, e.g. a tapered path, and overcome fitting problems during surgery. This work investigates the current straight cutting path used for typical bone tumor resection and compares it to a proposed tapered cutting path in terms of both implant fitting and stress analysis. Finite element analysis software is used to simulate a compression force exerted over the femur bone. Different taper cut angles are studied and results are reported to obtain an ideal angle for resection. Results are presented to evidence the need to evolve from the current resection technique in order to minimize the number of revision surgeries and for a better quality of life of patients under this type of surgical procedure.