High degree of alignment precision associated with total knee arthroplasty performed using a surgical robot or handheld navigation

Tony S Shen; Tyler J Uppstrom; Paul J Walker; Jonathan S Yu; Ryan Cheng; David J Mayman; Seth A Jerabek; Michael P Ast

doi:10.1007/s00167-023-07495-9

High degree of alignment precision associated with total knee arthroplasty performed using a surgical robot or handheld navigation

Knee Surg Sports Traumatol Arthrosc. 2023 Nov;31(11):4735-4740. doi: 10.1007/s00167-023-07495-9. Epub 2023 Jun 29.

Authors

Tony S Shen¹, Tyler J Uppstrom², Paul J Walker³, Jonathan S Yu³, Ryan Cheng², David J Mayman², Seth A Jerabek², Michael P Ast²

Affiliations

¹ Adult Reconstruction and Joint Replacement Service, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA. shent@hss.edu.
² Adult Reconstruction and Joint Replacement Service, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA.
³ Department of Orthopaedic Surgery, UCLA, Los Angeles, CA, USA.

PMID: 37382709
DOI: 10.1007/s00167-023-07495-9

Abstract

Purpose: The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using different computer-assisted technologies.

Methods: Patients who underwent a primary TKA using an imageless accelerometer-based handheld navigation system (KneeAlign2®, OrthAlign Inc.) or computed tomography-based large-console surgical robot (Mako®, Stryker Corp.) from 2017 to 2020 were retrospectively reviewed. Templated alignment targets and demographic data were collected. Coronal plane alignment of the femoral and tibial components and tibial slope were measured on postoperative radiographs. Patients with excessive flexion or rotation preventing accurate measurement were excluded.

Results: A total of 240 patients who underwent TKA using either a handheld (n = 120) or robotic (n = 120) system were included. There were no statistically significant differences in age, sex, and BMI between groups. A small but statistically significant difference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° difference between templated and measured alignments, p = 0.024), though this is likely clinically insignificant. There were no significant differences in the precision of the tibial resection between the handheld and robotic groups (coronal plane 0.9° vs. 1.0°, n.s.; sagittal plane 1.2° vs. 1.1°, n.s.). There were no significant differences in the rate of overall precision between cohorts (n.s.).

Conclusions: A high degree of component alignment precision was observed for both imageless handheld navigation and CT-based robotic cohorts. Surgeons considering options for computer-assisted TKA should take other important factors, including surgical principles, templating software, ligament balancing, intraoperative adjustability, equipment logistics, and cost, into account.

Level of evidence: III.

Keywords: Coronal alignment; Enabling technology; Imageless navigation; Robotics; Total knee arthroplasty.