3D Surgical Planning for Customized Devices in Orthopaedics: Applications in Massive Hip Reconstructions of Oncological Patients

This study investigates the morphological impact of using three-dimensional (3D) printed custom implants in surgical hip reconstruction compared to the conventional bone graft and standard size implant methods. An amount of 16 patients at the Rizzoli Orthopaedic Institute who underwent hip reconstruction surgery for tumors involving the P2 pelvis region were selected using stratified sampling. Half of them were randomly selected to receive 3D-printed implants, and the other half were selected to receive standard implants with bone grafts. Six months post-surgery, computed tomography (CT) scans were used to identify the hip joint center of rotation and to measure greater the trochanter offset and acetabular inclination angle. These CT scans were also used to construct a 3D model of the pelvis for 3D measurements. The results show no significant differences in accuracy, using Student’s t-test and Mann–Whitney U-test (p-value > 0.05), between the two methods for reconstructing the hip joint center of rotation or greater trochanter offset. However, 3D-printed implants showed statistically significant greater precision, using Student’s t-test (p-value < 0.05), in reconstructing the acetabular inclination angle compared to the conventional bone graft and standard-sized off-the-shelf implants. This superior precision reduces the risk of impingement of the femur implant neck with the acetabulum implant cup, which directly relates to improved implant survivorship. These findings support the continued exploration of 3D printing technology for personalized orthopedic solutions.