Robot-Assisted (RA) Versus Conventional Total Knee Replacement

A 2-Year Clinical Comparison

Henry R. Boucher, MD; Nijo Abraham, BSE, MSE; Ji Won Lee, CRNP; Caleb Grieme, BSE, MS; Paolo Diaz Rigor, BS; Michael J. Markel, BS; Paulina Szakiel, MS; Sameer Desale, MS


Curr Orthop Pract. 2022;33(3):243-251. 

In This Article

Abstract and Introduction


Background: Robotic-assisted (RA) technology is becoming increasingly popular in total knee arthroplasty (TKA) due to its improved alignment, accuracy, and precision compared with the conventional TKA. Despite reported benefits, disagreements exist regarding patient-reported outcomes and complication rates comparing RA TKA and conventional TKA. Thus, the purpose of the study is to report differences in patient outcomes and complication rates between patients who underwent RA versus conventional TKA.

Methods: The authors retrospectively reviewed 239 primary knee arthroplasty cases (n = 137 robot-assisted and n = 102 conventional TKA) performed by a single fellowship-trained orthopaedic surgeon from January 1, 2016 to February 26, 2019. The electronic medical record and patient outcomes database were reviewed for demographic characteristics (age, sex, body mass index, and comorbidities), patient-reported outcomes (Short Form Health Survey and Oxford Knee Score), 90-day complications, and revision rates.

Results: There was no statistically significant difference in patient-reported outcomes between conventional versus RA groups at two time points: preoperative and 2-year. Differences remained insignificant after controlling for age, sex, body mass index, and comorbidities. There was no statistically significant difference between the conventional and RA groups in revision rates (0.7% and 1%, respectively; P = 1.00) or complication rates (1.5% and 3.9%, respectively; P = 0.406).

Conclusions: There were no differences in 90-day complications, revisions, and patient-reported outcome scores between RA TKA and conventional TKA groups at short-term follow-up. Surgeons can expect similar clinical outcomes without an increase in complications while taking advantage of increased accuracy in alignment and component placement. Further long-term study of RA TKA outcomes is warranted.

Level of Evidence: Level III.


Robotic-assisted (RA) technology is becoming increasingly popular in total knee arthroplasty (TKA). Mechanically, robotic-assisted TKA results in better alignment, accuracy, and precision compared to conventional TKA.[1–3] Studies suggest that this technology can allow for less soft-tissue trauma and improved patient safety.[1–4]

Despite reported benefits, however, there is disagreement on whether RA TKA is associated with better clinical outcomes than conventional TKA. One of the few long-term randomized studies did not find a difference in clinical outcomes between the two.[5] However, a recent meta-analysis of RA versus conventional TKA noted improved outcome scores.[1] Other studies have demonstrated improved recovery and higher patient satisfaction with RA TKA.[6–9] Although it is well reported that RA improves the technical aspects of TKA, without definitive benefit of patient outcomes, it may be difficult to justify the technology cost, associated learning curve and potential added procedural time of RA TKA.[5] To the authors' knowledge, none of the papers investigated subgroups of patients with high deformity, body mass index (BMI), or high numbers of comorbidities.

Another gap in the literature pertains to postoperative complications, which is an important component of RA TKA outcomes but sparsely reported. One meta-analysis that evaluated surgery-related complications and infections did not find any significant difference between RA TKA and conventional TKA, but the report did not consider complications such as deep vein thrombosis (DVT), periprosthetic fracture, and prosthetic instability.[4] In addition, outcomes controlling for possible confounders such as comorbidities are important but infrequently reported.

Given the lack of consensus on the relative benefits of RA TKA for functional outcomes and the lack of data on complication rates, the authors aimed to compare patient outcomes and complication rates at short-term follow-up between patients who underwent RA TKA and those who underwent conventional TKA.