Towards markerless robot-assisted navigation with 2D-3D registration for anterior cruciate ligament reconstruction.

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Abstract

[Indexed for MEDLINE] Conflict of interest statement: Declaration of competing interest The authors have no relevant interests to declare. This work was funded in part by the University of Denver. 6. Clin Biomech (Bristol). 2019 Oct;69:168-177. doi: 10.1016/j.clinbiomech.2019.07.026. Epub 2019 Jul 24. Does navigated patellar resurfacing in total knee arthroplasty result in proper bone cut, motion and clinical outcomes? Belvedere C(1), Ensini A(2), Tamarri S(3), d'Amato M(4), Barbadoro P(4), Feliciangeli A(4), Rao A(4), Leardini A(3). Author information: (1)Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. Electronic address: belvedere@ior.it. (2)Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy; Department of Orthopaedic Surgery, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. (3)Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. (4)Department of Orthopaedic Surgery, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. BACKGROUND: In total knee arthroplasty with patellar resurfacing, patellar bone preparation, component positioning and motion assessments are still not navigated. Only femoral/tibial component positioning is supported by computer-assistance. The aim of this study was to verify, in-vivo, whether knee surgical navigation extended to patellar resurfacing, by original instrumentation and procedures for patellar-based tracking, could achieve accurate patella preparation in terms of original thickness restoration, bone cut orientation, and normal knee motion. METHODS: An additional navigation system for patellar data acquisition was used together with a standard navigation system for total knee arthroplasty in 20 patients. This supported the surgeon for patellar resurfacing via measurement of removed bone thickness, three-dimensional patellar cut orientations, and patello-femoral motion. Radiological and clinical examinations at 6 and 24-month follow-up were also performed. FINDINGS: The medio-lateral patellar-bone cut orientation was respectively 0.5° (standard deviation: 3.0°) and 1.4° (1.7°) lateral tilt, as measured via navigation and post-operatively on the Merchant x-ray view. The cranio-caudal orientation was 3.8° (7.2°) of flexion. The thickness variation between patellar pre- and post-implantation was 0.2 (1.3) mm. Immediately after implantation, patello-femoral as well as tibio-femoral kinematics was within the normality. Good radiological and clinical examinations at 6 and 24-month follow-up were also observed. INTERPRETATION: For the first time, the effect of patellar navigation for its resurfacing was assessed in-vivo during surgery, with very good results for thickness restoration, proper cut orientation, and normal knee motion. These results support the introduction of patella-related navigation-based surgical procedures for computer-assisted total knee arthroplasty. Copyright © 2019 Elsevier Ltd. All rights reserved. DOI: 10.1016/j.clinbiomech.2019.07.026