Reconstruction for Massive Proximal Tibial Bone Defects Using Patient-customized Three-dimensional-printed Metaphyseal Cones in Revision Total Knee Arthroplasty

Abstract Background: The reconstruction of massive bone defects is one of the main challenges in revision total knee arthroplasty (RTKA). Although several methods are available, each of them has its prominent shortcomings. The purpose of this study is to review the clinical outcomes of RTKA with massive proximal tibial bone defects using patient-customized three-dimensional (3D)-printed highly porous metaphyseal cones.Methods: We retrospectively reviewed seven RTKAs with Anderson Orthopaedic Research Institute (AORI) type III tibial defects using patient-customized 3D-printed highly porous metaphyseal cones, which have been performed at a single institution between 2016 and 2018. Results: The mean age at diagnosis of the patients was 68 years old (61-77). The mean length of follow-up was 25.3 months (19-36). At the latest follow-up, no aseptic loosening or prosthetic joint infection has been determined. The mean HSS increased from 49 (39-63) to 78 (70-83) (P<0.01); the mean WOMAC increased from 59 (46-73) to 26 (12-38) (P<0.01). All patients obtained the range of motion and mechanical alignment improvement postoperatively.Conclusion: The patient-customized 3D-printed metaphyseal cone could be a promising technique in addressing severe tibial defects in RTKA. Our study shows encouraging short-term clinical and radiological outcomes with no aseptic loosening, periprosthetic infection, or fracture. Nevertheless, further follow-up and the expansion of sample size are needed to demonstrate the advantage of this innovative technique fully.