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Robotic-assisted vs Conventional Total Knee Arthroplasty| Difference in Outcomes and Pain



  • In response to the ongoing opioid epidemic, total joint arthroplasty surgery has embraced opioid stewardship.

  • Total knee arthroplasties are among the most common orthopedic surgeries and have spearheaded robotic assistance.

  • Recent studies have shown decreased postoperative pain levels for patients who underwent robotic-assisted total knee arthroplasties compared to those who underwent conventional total knee arthroplasty.



The ongoing opioid epidemic has long been attributed to over-prescribing by providers and opioid mishandling by patients. Annual opioid prescribing rates increased from 1999 to 2012 eventually peaking at 81.3 prescriptions per 100 persons (1). Providers have since drastically altered their prescribing practices resulting in annual decreases in prescribing rates since 2012, with data from 2020 demonstrating now only 43.3 prescriptions per 100 persons (Figure 1) (2).

Figure 1. Annual changes in the overall and high-dosage opioid prescribing trends from 2006 to 2017 of the United States. Sourced from Prescribing practices. Centers for Disease Control and Prevention. Published August 13, 2019.

Despite the progress, all but three states (Delaware, New Hampshire, and South Dakota) reported increased rates of drug overdose deaths between 2019-2020, with 38 states reporting statistically significant rate increases (Figure 2) (3). Orthopaedic surgery contributes the third highest average number of opioid prescriptions per prescriber, following primary care physicians and pain management specialists (4).

Figure 2. Change in the annual rate of drug overdose deaths by state from 2019 to 2020. Sourced from 2019-2020 drug overdose Death Rate Percent change map. Centers for Disease Control and Prevention.

Within the field of orthopaedic surgery, total knee arthroplasty (TKA) is one of the most common surgeries performed. The American Joint Replacement Registry (AJRR) reported 995,410 primary TKAs performed between 2012 to 2019, and the Journal of Rheumatology projects a 401% increase in annual procedures by 2040 (Figure 3 & Figure 4) (5,6). This anticipated increasing caseload warrants an emphasis on optimal analgesic prescribing. A study involving 90 million patients throughout 56 U.S. hospital systems found that from 2014 to 2017, the proportion of patients who received an opioid prescription within 60 days of discharge following TKA increased from 81.9% to 91.5%. This increase in prescribing came without an associated change in patient-reported pain at the time of discharge (7). This complex situation requires investigation into potential methods to reduce postoperative pain and opioid utilization after TKA. This analysis aims to highlight the potential effectiveness of robotic-assisted TKA in improving postoperative outcomes and pain.

Figure 3. Cumulative Procedure Volume, 2012-2019 (N=1,897,050). Sourced from the American Joint Replacement Registry (AJRR): 2021 Annual Report. Rosemont, IL: American Academy of Orthopaedic Surgeons (AAOS), 2021.

Figure 4. Distribution of Arthroplasty Procedures, 2012-2019 (N=1,825,551) Sourced from the American Joint Replacement Registry (AJRR): 2021 Annual Report. Rosemont, IL: American Academy of Orthopaedic Surgeons (AAOS), 2021.


Robotic-assisted TKAs (RA-TKA) aims to increase surgical success through critical preoperative planning, the creation of virtual guidelines for bone and cartilage removal, and optimizing intraoperative bone cuts. Studies examining RA-TKA have shown that this technique improves prosthetic alignment, decreases revision rate, and decreases case-by-case variance (8-13).

A nationwide database study queried over 755,000 TKAs from 2007 to 2018, with approximately 5,000 being RA-TKAs, showed that patients who underwent conventional TKA (C-TKA) had a higher level of manipulation under anesthesia intraoperatively and a higher instance of prosthetic revision at the one-year mark (14). Patients in the C-TKA cohort additionally had higher levels of systemic complications during their hospital stay including but not limited to deep vein thrombosis, altered mental status, pulmonary embolism, acute renal failure, cerebrovascular event, and respiratory failure (14).

Furthermore, patients in the C-TKA cohort had higher levels of average MME consumption at 90 days, six months, and one year after discharge (14). However, the findings of the study must be tempered against the fact that the percentage of RA-TKA’s was very small in the study cohort, performed by much fewer surgeons, and generally performed on “healthier” patients.

A 2020 questionnaire-based study compared RA-TKA and C-TKA at the six-month follow-up visit (15). Results of the study showed marked improvement in patient satisfaction, improved early functional recovery, decreased pain, and decreased opioid requirements for the RA-TKA cohort compared to that of the C-TKA cohort (15). A 2022 retrospective review investigated the postoperative RA-TKA outcome of patients who had previously undergone a contralateral C-TKA (16). Patients were consulted on post-operative day one as well as the three-month, six-month, and one-year postoperative mark (16). Patients expressed less stiffness, decreased pain and need for continued analgesic support, and greater knee flexion after their RA-TKA when compared to their previous C-TKA (16).


Within orthopaedic surgery, TKAs are the most performed arthroplasty procedures. Early research shows that compared to the conventional TKA approach, robotic-assisted TKAs demonstrate improved accuracy of prosthetic alignment, improved outcomes, and decreased opioid use. Ideally, future studies might also focus on investigating how robotic-assisted TKA affects postoperative pain and opioid consumption.


  1. Prescribing practices. Centers for Disease Control and Prevention. Published August 13, 2019. Accessed June 26, 2022.

  2. U.S. opioid dispensing rate maps. Centers for Disease Control and Prevention. Published November 10, 2021. Accessed June 26, 2022.

  3. 2019-2020 drug overdose Death Rate Percent change map. Centers for Disease Control and Prevention. Published February 16, 2021. Accessed June 26, 2022.

  4. Guy GP, Zhang K. Opioid prescribing by specialty and volume in the U.S. American Journal of Preventive Medicine. Published September 12, 2018. doi:10.1016/j.amepre.2018.06.008.

  5. American Joint Replacement Registry (AJRR): 2021 Annual Report. Rosemont, IL: American Academy of Orthopaedic Surgeons (AAOS), 2021.

  6. Singh JA, Yu S, Chen L, Cleveland JD. Rates of total joint replacement in the United States: Future projections to 2020–2040 using the National Inpatient Sample. The Journal of Rheumatology. Published April 2019;46(9):1134-1140. doi:10.3899/jrheum.170990.

  7. Shah R, Kuo Y, Westra J, Lin Y, Raji MA. Opioid Use and Pain Control After Total Hip and Knee Arthroplasty in the US, 2014 to 2017. JAMA Netw Open. 2020;3(7):e2011972. doi:10.1001/jamanetworkopen.2020.11972

  8. Chin PL, Yang KY, Yeo SJ, Lo NN. Randomized control trial comparing radiographic total knee arthroplasty implant placement using computer navigation versus conventional technique. The Journal of Arthroplasty. Published August 2005;20(5):618-626. doi:10.1016/j.arth.2005.04.004.

  9. Hetaimish BM, Khan MM, Simunovic N, Al-Harbi HH, Bhandari M, Zalzal PK. Meta-analysis of navigation vs conventional total knee arthroplasty. The Journal of Arthroplasty. Published June 2012;27(6):1177-1182. doi:10.1016/j.arth.2011.12.028.

  10. Park SE, Lee CT. Comparison of robotic-assisted and conventional manual implantation of a primary total knee arthroplasty. The Journal of Arthroplasty. Published October 2007;22(7):1054-1059. doi:10.1016/j.arth.2007.05.036.

  11. Batailler C, White N, Ranaldi FM, Neyret P, Servien E, Lustig S. Improved implant position and lower revision rate with robotic-assisted Unicompartmental Knee Arthroplasty. Knee Surgery, Sports Traumatology, Arthroscopy. Published July 31, 2018;27(4):1232-1240. doi:10.1007/s00167-018-5081-5.

  12. Song EK, Seon JK, Yim JH, Netravali NA, Bargar WL. Robotic-assisted TKA reduces postoperative alignment outliers and improves gap balance compared to conventional TKA. Clin Orthop Relat Res. Published January 2013;471(1):118-126. doi:10.1007/s11999-012-2407-3

  13. Song EK, Seon JK, Park SJ, Jung WB, Park HW, Lee GW. Simultaneous bilateral total knee arthroplasty with robotic and conventional techniques: a prospective, randomized study. Knee Surg Sports Traumatol Arthrosc. 2011;19(7):1069-1076. doi:10.1007/s00167-011-1400-9

  14. Ofa SA, Ross BJ, Flick TR, Patel AH, Sherman WF. Robotic total Knee Arthroplasty vs conventional total Knee Arthroplasty: A nationwide database study. Arthroplasty Today. Published November 7, 2020;6(4). doi:10.1016/j.artd.2020.09.014.

  15. Wilson C. Does robotic knee surgery benefit a patient’s recovery after TKA surgery compared with conventional methods? Open Access Journal of Biomedical Science. 2020;2(2). doi:10.38125/oajbs.000180

  16. Ali M, Kamson A, Yoo C, Singh I, Ferguson C, Dahl R. Early superior clinical outcomes in robotic-assisted TKA compared to conventional TKA in the same patient: A comparative analysis. J Knee Surg. Published online 2022. doi:10.1055/s-0042-1743232

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