Study Design: Biomechanical study.Objective: To evaluate the performance of the contact surface for 3D printed patient-specific cages using CT-scan 3D endplate reconstructions in comparison to the contact surface of commercial cages.Summary of Background Data: Previous strategies to improve the surface of contact between the device and the endplate have been employed to attenuate the risk of cage subsidence. Patient-specific cages have been used to help, but only finite-element studies have

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... uated the effectiveness of this approach. There is a possible mismatch between the CT-scan endplate image used to generate the cage and the real bony endplate anatomy that could limit the performance of the cages.Methods: A cadaveric model is used to investigate the possible mismatch between 3D printed patient-specific cages and the endplate and compare them to commercially available cages (Medtronic Fuse and Capstone). Contact area and contact stress were used as outcomes.Results: When PS cage was compared to the Capstone cage, the mean contact area obtained was 100±23.6 mm² and 57.5±13.7 mm², respectively (p<0.001). When compared to the Fuse cage, the mean contact area was 104.8±39.6 mm² and 55.2±35.1 mm², respectively(p<0.001).Conclusion: Patient-specific cages improve the contact area between the implant and the endplate surface, reducing the contact stress and the risk of implant subsidence during LIF surgeries.Level of Evidence: N/A