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J Knee Surg
DOI: 10.1055/a-2664-7551
Original Article

Computed Tomography-Based Analysis of Implant Positioning after Total Knee Arthroplasty: A Randomized Controlled Trial Comparing Conventional and Robotic Arm-Assisted Procedures

Authors

  • Clément Horteur 

    1   Department of Orthopaedic Surgery and Sport Traumatology, Grenoble South Teaching Hospital, Echirolles, France

  • Benoit Gaulin

    1   Department of Orthopaedic Surgery and Sport Traumatology, Grenoble South Teaching Hospital, Echirolles, France

  • Pierre Pascal

    2   Department of Radiology, Grenoble-Alpes University Hospital, Grenoble, France

  • Corentin Leroy

    4   Data Engineering Unit, CIC, Public Health Department, Université Grenoble Alpes, Inserm, Grenoble Alpes University Hospital, Grenoble, France

  • Joris Giai

    5   Université Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, CHU Grenoble Alpes, TIMC, INSERM CIC1406, Grenoble, France

  • Jérôme Murgier

    3   Department of Orthopaedic Surgery, Clinique Aguilera RAMSAY, Santé Biarritz, France

  • Johannes Barth

    3   Department of Orthopaedic Surgery, Clinique Aguilera RAMSAY, Santé Biarritz, France

  • Régis Pailhé

    3   Department of Orthopaedic Surgery, Clinique Aguilera RAMSAY, Santé Biarritz, France
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Abstract

The aim of this study was to evaluate the deviation from the surgical plan of femoral and tibial components positioning after robotic total knee arthroplasty (R-TKA) compared with conventional TKA (C-TKA) based on postoperative three-dimensional computed tomography (3D-CT). This prospective randomized trial included 60 patients: 29 in the C-TKA group and 31 in the R-TKA one. Early postoperative 3D-CT-based analysis of implants positioning was performed. Measurements were performed twice by two observers, showing good to excellent intra- and interobserver reproducibility (interclass coefficient ranging from 0.71 to 0.96). Absolute deviations from the surgical plan (mechanical alignment in the C-TKA group and personalized alignment in the R-TKA group) were compared between groups. Primary endpoint was coronal lower limb frontal alignment: hip–knee–ankle (HKA) angle. Secondary endpoints were frontal, sagittal, and rotational positioning of both tibial and femoral components. Planned frontal lower limb alignment was similarly achieved in both group: HKA angle mean difference was 2.28 ± 1.81 degrees in the C-TKA group and 1.84 ± 1.46 degrees in the R-TKA group (p = 0.379). Deviations from the surgical plan were lower in the R-TKA group compared with the C-TKA group for all parameters, except tibial rotation (9.02 ± 4.51 vs. 7.42 ± 3.96 degrees, respectively). These differences turned out to be statistically significant only for sagittal alignment of both femoral (1.71 ± 1.34 vs. 3.61 ± 2.05 degrees, p < 0.001) and tibial (3.78 ± 1.15 vs. 4.94 ± 1.99 degrees, p = 0.018) components. Accuracy in achieving planned coronal lower limb alignment is not higher using R-TKA compared with C-TKA. Regarding component positioning, R-TKA appears superior in the sagittal plane while no significant differences were identified in terms of frontal alignment and rotation.

Level of Evidence I.

Keywords

robotic - total knee arthroplasty - computed tomography


Publication History

Received: 21 March 2025

Accepted: 23 July 2025

Article published online:
06 August 2025

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