Commentary: “The Impact of Surgical Trainee Involvement in Total Knee Arthroplasty: A Systematic Review of Surgical Efficacy, Patient Safety, and Outcomes”

Ryan S. Marder, Neil V. Shah, Aditya V. Maheshwari*

Department of Orthopaedic Surgery and Rehabilitation Medicine, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, USA

Surgical trainee involvement in patient care has raised concerns about the risk of potentiating adverse events and increased costs, and has led to patient discomfort and fear1,2. Moreover, new bundled-payment systems3, resident duty-hour restrictions4,5, and an increased focus on quality measure-based reimbursement4-6 have magnified the relevancy of the concerns surrounding surgical trainee participation in patient care in the United States (U.S.). However, trainee participation in the operating room is not only essential but remains one of the most crucial aspects for their progression towards becoming the next generation of proficient surgeons. Total knee arthroplasty (TKA) is one of the most commonly performed and protocol-driven orthopaedic surgeries7,8, and has been identified as a substantial training requirement by both the Accreditation Council for Graduate Medical Education (ACGME) in the U.S. and the Specialty Advisory Committee (SAC) in the United Kingdom for residents and surgical registrars, respectively9,10. Based on these factors, TKA procedures have been commonly utilized as models for several quality performance analyses, and can be used to evaluate the impact of trainee involvement in patient care.

Our study11 highlights and details the current consensus and controversies that remain concerning trainee involvement in TKA in terms of surgical efficacy, patient safety, and functional outcomes. While our study confirmed that more time is spent in the operating room during cases of TKA with trainee involvement, the overall complication rates and functional outcomes were similar. While data concerning the cost of TKA procedures was limited, evidence did point towards an increased total cost in cases performed by teaching services compared to private services. For our present study, conclusions must be tempered due to the inherent heterogeneity that exists within the literature and the many confounding factors at play. The level of trainee experience, the degree of trainee participation, and the amount of senior surgeon supervision/intervention during TKA procedures were inconsistently reported. Moreover, most of these studies are large database studies and have their own intrinsic limitations and biases, and do not have a good control or a matched group for a higher level of evidence.

One possible way to mitigate the above limitations is a single stage bilateral comparative study design with different sides for the senior surgeon and the trainee12-14. Although this model provides the most direct comparison by controlling the confounding variables as much as possible, they are limited with their ability to differentiate other outcomes, like systemic complications and other hospital-based logistics like length of stay, mortality, and total cost, that are independent of the laterality. In addition, preoperative and technical differences between the two sides may exist, creating another bias. In a recent study, where the trainee did the right side first followed by the attending on the left side on most patients, Sheridan et al.12 found similar tourniquet times and outcomes between the two groups. Similarly, in a study by Goto et al.13 where the attending first did the knee with a lower functional score, there was no difference in functional and radiographic scores between the two groups, although the trainee took significantly longer to complete the TKA procedure. However, the level of the trainee and the degree of the attending involvement in supervision was not specified in either of these studies.

Our group14 recently utilized a similar model eliminating some of the earlier biases, and found that the attending surgeon completed his side significantly faster (incision to dressing, 70.2 minutes vs. 96.9 minutes, p<0.001) compared to the chief residents (PGY-5), presenting an opportunity cost of one TKA to the attending and the hospital per three TKAs performed with residents’ active participation. These findings should be interpreted with the fact that the residents do play a significant role in several other ancillary workload and save a lot of time and pressure for the attending indirectly. In addition, our study sub-divided the TKA procedure into eight standardized and critical steps, and the “exposure” and “closure” steps were found to be the most time-consuming/time-difference steps of the surgery for the chief resident cohort in comparison to the attending surgeon. By identifying the limiting steps of the TKA procedure, trainees can focus on and practice these techniques in the operating room and simulation models to become more efficient and skilled at completing these steps. This is important as 45% of primary TKA procedures in the U.S. are performed by surgeons who are not fellowship trained, and thus residency training becomes pivotal15. Despite these differences in operative timing, functional outcomes 90 days postoperatively (Knee Society Score [KSS] attending vs. resident, 95.6 vs. 91.1; p=0.414), and intraoperative complications (none recorded) and patient laterality preference (attending vs. resident, 14.2% vs. 10.2%; p=0.393) at 1-year follow-up were comparable in our study14.

Optimizing and enhancing trainee hands-on experience during surgical procedures must be weighed against the potential adverse outcomes that may be associated with such involvement. Although one-third of all orthopaedic procedures performed are completed at teaching hospitals16, concern among patients, payors, and policymakers has become more relevant in recent years. These concerns are not limited to TKA and are also present during other orthopaedic procedures (e.g., total hip arthroplasty) and in various other surgical subspecialties. Our systematic review11 and the recent single-staged bilateral TKA analyses12-14 should help to reassure all those concerned that trainee involvement in TKA is relatively safe. We do emphasize that ‘hands-on’ training is a necessary investment to create a future skilled workforce and should not be compromised. Future studies should supplement these results and analyze the impact of trainee involvement in various orthopaedic and non-orthopaedic procedures in an effort to enhance patient care and safety.

Conflict of interest

Dr. Maheshwari, Dr. Shah, and Mr. Marder declare that there is no conflict of interest.


This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.


  1. Nahhas CR, Yi PH, Culvern C, et al. Patient Attitudes Toward Resident and Fellow Participation in Orthopedic Surgery. J Arthroplasty. 2019; 34(9): 1884-1888. e1885.
  2. Edgington JP, Petravick ME, Idowu OA, et al. Preferably Not My Surgery: A Survey of Patient and Family Member Comfort with Concurrent and Overlapping Surgeries. J Bone Joint Surg Am. 2017; 99(22): 1883-1887.
  3. Rana AJ, Bozic KJ. Bundled payments in orthopaedics. Clin Orthop Relat Res. 2015; 473(2): 422-425.
  4. Ahmed N, Devitt KS, Keshet I, et al. A systematic review of the effects of resident duty hour restrictions in surgery: impact on resident wellness, training, and patient outcomes. Ann Surg. 2014; 259(6): 1041-1053.
  5. Antiel RM, Reed DA, Van Arendonk KJ, et al. Effects of duty hour restrictions on core competencies, education, quality of life, and burnout among general surgery interns. JAMA Surg. 2013; 148(5): 448-455.
  6. Holt G, Nunn T, Gregori A. Ethical dilemmas in orthopaedic surgical training. J Bone Joint Surg Am. 2008; 90(12): 2798-2803.
  7. Hoerlesberger N, Glehr M, Amerstorfer F, et al. Residents' Learning Curve of Total Knee Arthroplasty Based on Radiological Outcome Parameters: A Retrospective Comparative Study. J Arthroplasty. 2021; 36(1): 154-159.
  8. Garrett WE, Jr., Swiontkowski MF, Weinstein JN, et al. American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. J Bone Joint Surg Am. 2006; 88(3): 660-667.
  9. Orthopaedic Surgery Minimum Numbers: Review Committee for Orthopaedic Surgery. Published 2014. Accessed 14 Jan 2022.
  10. Beattie N, Maempel JF, Roberts S, et al. Surgery performed by supervised registrars does not adversely affect medium-term functional outcomes after total knee replacement. Ann R Coll Surg Engl. 2018; 100(1): 57-62.
  11. Marder RS, Shah NV, Naziri Q, et al. The impact of surgical trainee involvement in total knee arthroplasty: a systematic review of surgical efficacy, patient safety, and outcomes. Eur J Orthop Surg Traumatol.
  12. Sheridan GA, Moshkovitz R, Masri BA. Simultaneous bilateral total knee arthroplasty: similar outcomes for trainees and trainers. Bone Jt Open. 2022; 3(1): 29-34.
  13. Goto K, Katsuragawa Y, Miyamoto Y. Outcomes and component-positioning in total knee arthroplasty may be comparable between supervised trained surgeons and their supervisor. Knee Surg Relat Res. 2020; 32(1): 1-6 .
  14. Maheshwari AV, Garnett C, Cheng TH, et al. Does Resident Participation Influence Surgical Time and Clinical Outcomes? An Analysis on Primary Bilateral Single-Staged Sequential Total Knee Arthroplasty. Arthroplasty Today. In Press.
  15. Pour AE, Bradbury TL, Horst P, et al. Trends in primary and revision knee arthroplasty among orthopaedic surgeons who take the American Board of Orthopaedics part II exam. Int Orthop. 2016; 40(10): 2061-2067.
  16. Bao MH, Keeney BJ, Moschetti WE, et al. Resident Participation is Not Associated With Worse Outcomes After TKA. Clin Orthop Relat Res. 2018; 476(7): 1375-1390.

Article Info

Article Notes

  • Published on: May 13, 2022


  • Orthopaedic surgery
  • Total knee arthroplasty
  • Residency
  • Trainee
  • Outcomes
  • Patient safety


Dr. Aditya V. Maheshwari, MD, MPH,
Associate Professor of Orthopaedics, Director Adult Reconstruction and Musculoskeletal Oncology, SUNY Downstate Health Science University, Brooklyn, New York, USA;

Copyright: ©2022 Maheshwari AV. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License.