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

Abstract

Purpose The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using diferent 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 lexion 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 signiicant diferences in age, sex, and BMI between groups. A small but statistically signiicant diference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° diference between templated and measured alignments, p = 0.024), though this is likely clinically insigniicant. There were no signiicant diferences 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 signiicant diferences 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.

Navigating the Divide: A Comprehensive Review of the Mechanical and Anatomical Axis Approaches in Total Knee Replacement

“…A study comparing the precision of bony resections during TKA, using different computer-assisted methods, found no statistically significant differences in age, sex, and BMI between groups. However, a minor yet statistically significant distinction in distal femoral resection precision was noted, although it was likely clinically insignificant [9]. Personalized knee guides have emerged as a cost-effective and accessible technology for achieving precise, personalized TKA alignment.…”

“…Establishing femoral component rotation involves making a posterior femoral cut parallel to the femur's mechanical axis. Various methods, such as measured resection or gap balancing techniques, are employed to achieve desired femoral rotation targets [6][7][8][9]. Considerations include maintaining appropriate ligament tension, optimizing quadriceps function, and ensuring proper patella tracking.…”

Conventionally instrumented inverse kinematic alignment for total knee arthroplasty: How is it done?

“…Furthermore, according to the 2023 Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), revision rates for procedures using image‐derived instrumentation or custom‐made cutting blocks, are higher when compared to TKA without technology assistance [ 43 ]. While improved accuracy of cuts using robotic assistance has been demonstrated by some studies, multiple randomised studies now demonstrate no long‐term clinical benefit for robotic‐assisted TKA [ 4 , 9 , 26 , 31 , 32 , 42 ].…”