Ergonomic Evaluation of Different Surgeon Positions for Total Knee Arthroplasty Surgery

Round 1

Reviewer 1 Report

Abstract:

The abstract requires revision as it currently contains detailed information regarding methods (including software names) and results (REBA details) that should be presented in a more general manner. Additionally, it should explicitly reference the four cases (A, B, C, D) to enhance clarity. However, it lacks essential information, such as the study's rationale, the criteria used to define the four positions, who determined these criteria, and a concluding sentence.

Introduction:

In the introduction section, I recommend conducting a more thorough literature review. Specifically, consider incorporating the following references:

 DOI: 10.1097/BTO.0000000000000092

doi: 10.1186/s12911-020-1086-3

DOI: 10.24938/kutfd.815377

Materials and Methods:

In line 59, please clarify how the posture's primary aspects were assessed. Did you evaluate them across various surgeons or only within the authoring team?

Lines 74-78: The described procedures appear to be associated with a tibial-first approach. Are the results applicable to a femur-first approach? Do they also apply to newer approaches such as kinematic alignment or emerging technologies like robotics?

Lines 84-92: The assumptions mentioned may not hold for a generic surgeon operating on a typical patient in a standard operating theater. Please discuss how these results can be extrapolated to a broader context.

In line 98, provide the full name of the software used, including its producer.

Line 103: Avoid repetition in the text, as the software has already been defined.

Lines 104-107: Please address this issue earlier in the manuscript.

In line 123, specify which figure among those mentioned by the author should be reported.

Statistical Analysis:

Given the use of average and standard deviation, did the authors assess data normality?

As multiple comparisons were made, it's important to explain the rationale for using an alpha value of 0.05. Did the authors employ any multiple-comparison correction methods?

Results:

Regarding Table 2, please clarify if the system can discriminate measurements with two digits. If not, consider using one-digit precision in the table.

Lines 191-192 contain unclear sentences that need further clarification.

Table 8:

Table 8 appears to be challenging to read. Consider highlighting the most crucial information to improve clarity.

the English is ok

Author Response

Dear reviewer 1,

Firstly, we would like to thank you for your comments and for allowing us to address the issues you raised in order to improve the quality of the manuscript. We greatly appreciate your observations and the time you have taken to provide constructive criticism and feedback on our manuscript.

We will respond to your comments and objections point by point and indicate the changes we propose to the manuscript to address your comments. We have highlighted the changes to the manuscript in red.

The abstract requires revision as it currently contains detailed information regarding methods (including software names) and results (REBA details) that should be presented in a more general manner. Additionally, it should explicitly reference the four cases (A, B, C, D) to enhance clarity. However, it lacks essential information, such as the study's rationale, the criteria used to define the four positions, who determined these criteria, and a concluding sentence.

We have rewritten the abstract according to your instructions, explaining the groups A, B, C and D, the criteria used to determine the positions and who defined them. We have considered that the abstract should contain the essential information of the manuscript and, to some extent, be a faithful and complete summary of the main results and their interpretation.

Introduction:

In the introduction section, I recommend conducting a more thorough literature review. Specifically, consider incorporating the following references:

DOI: 10.1097/BTO.0000000000000092

doi: 10.1186/s12911-020-1086-3

DOI: 10.24938/kutfd.815377

We have searched for the DOI: 10.1097/QCO.0000000000000092, but the article it refers us to is “Kalita A, Hu J, Torres AG. Recent advances in adherence and invasion of pathogenic Escherichia coli. Curr Opin Infect Dis. 2014 Oct;27(5):459-64. DOI: 10.1097/QCO.0000000000000092”, which has little to do with the topic of our manuscript. Can you re-identify the article you are referring to?

We have included the other two references you mentioned. Of notable interest is the paper by Ceyhan et al. and the conclusion that right-handed surgeons exert more effort when performing left-sided TKAs. We have commented on these publications in the discussion section.

Materials and Methods:

In line 59, please clarify how the posture's primary aspects were assessed. Did you evaluate them across various surgeons or only within the authoring team?

The authors of the study identified the four positions based on the most common positions used by surgeons performing TKA in our setting. It is possible that some surgeons may use a different position to those described, but we believe that the positions established are representative of a sufficiently large percentage of surgeons. We have indicated this in M&M.

Lines 74-78: The described procedures appear to be associated with a tibial-first approach. Are the results applicable to a femur-first approach? Do they also apply to newer approaches such as kinematic alignment or emerging technologies like robotics?

Thank you for your comments. We cannot state that the results can be extrapolated to techniques with initial femoral osteotomies, techniques with non-mechanical alignment, computer-, PSI-, or robotic-assisted surgery. There will probably be little difference, but as we have not analysed them, we cannot affirm anything, so this is a limitation of our study, which we include in the limitations section.

Lines 84-92: The assumptions mentioned may not hold for a generic surgeon operating on a typical patient in a standard operating theater. Please discuss how these results can be extrapolated to a broader context.

Thank you for your comment. Your statement is true, and we have considered it as a limitation of the study: “Thirdly, we studied the ergonomics of different positions in the same surgeon on the same patient. Differences in the body morphology of each surgeon may influence each position’s ergonomic risk. Nevertheless, we used a "typical" surgeon as a model: a mesomorphic male, 1.80m tall and weighing 75kg.”

We would like to emphasise that the results cannot be extrapolated with the following sentence: “There is no strict extrapolation of our results to other morphometric parameters of the surgeon and the patient.”

In the current design of a more extensive study, we use different surgeon and patient models (different morphometric characteristics) to obtain representative values. However, in the study reflected in the manuscript, the methodology used is with only one surgeon and patient model, so we agree with you that this is a limitation we have already considered.

In line 98, provide the full name of the software used, including its producer.

Kinovea is a completely free and open source video annotation tool designed for sports analysis and developed by Joan Charmant ([email protected]). We add information about it.

Line 103: Avoid repetition in the text, as the software has already been defined.

Corrected.

Lines 104-107: Please address this issue earlier in the manuscript.

Corrected. We have moved the description to the first time the software is mentioned in the text.

In line 123, specify which figure among those mentioned by the author should be reported.

I don't understand what you mean. Could you please explain? Figure 2 shows the groups analysed by the REBA method, Group A (neck, trunk, and legs) and Group B (arms, forearms, and wrists). We have used an example in position D of our study.

Statistical Analysis:

Given the use of average and standard deviation, did the authors assess data normality?

As stated in the manuscript, we examined the normal behaviour of the variables using the Kolmogorov-Smirnov test. In addition, the number of observations (n) exceeded the value of 30, which allows us to apply the central limit theorem and to consider, for statistical purposes, a normal behavior of the variable.

As multiple comparisons were made, it's important to explain the rationale for using an alpha value of 0.05. Did the authors employ any multiple-comparison correction methods?

No, we did not do a multiple comparison analysis. To clarify, we made a simple comparison between observer 1's first observation and observer 2's single observation. Observer 1 made two observations to assess intra-observer variability.

Results:

Regarding Table 2, please clarify if the system can discriminate measurements with two digits. If not, consider using one-digit precision in the table.

Thank you for your comment. The system gives the measurement to one decimal place. We use two decimals in the table to deal with averages for greater precision. However, we can adjust it to one decimal place.

Lines 191-192 contain unclear sentences that need further clarification.

Thank you for your comment. Lines 191-192 are a table footnote to explain the abbreviations in the table. It is not intended to be a sentence. We have changed the format of the table and the table footer to clarify this.

Table 8:

Table 8 appears to be challenging to read. Consider highlighting the most crucial information to improve clarity.

Thank you for your feedback. In the interests of clarity, we have decided to replace the table with two graphs showing the key information.

Reviewer 2 Report

It was an honor to review this paper. The authors have evaluated the ergonomics of the different standing positions of the TKA surgeon and state that the most ergonomic position for a right-handed surgeon to perform a left TKA is facing the left knee at the patient. However, it has to be noted that there are some problems with this paper.

1.Selection of the patient's position during TKA surgery is a complex issue that involves a combination of considerations, including aseptic requirements, assistant's position, surgical convenience,  and other complex factors in addition to the surgeon's ergonomic evaluation considerations.

2.Authors need to write more carefully and avoid low-level errors, such as 1.89cm tall patients (line 86) and 200mm long  operating table (line 88).

3.The form of the tables were confusing, and it is recommended that the tables be in the form of a traditional three-line table.

4.The 95% confidence intervals for Tables 3 and 4 were not necessary to show.

5.The results were repetitive with the contents of the tables, and it was suggested to streamline them.

6. Line 272-302. Variables such as worktable height, rest periods, muscle training, etc. did not appear to be included in this study, and discussion of these appeared to be unnecessary.

none

Author Response

Dear reviewer 2,

Firstly, we would like to thank you for your comments and for allowing us to address the issues you raised in order to improve the quality of the manuscript. We greatly appreciate your observations and the time you have taken to provide constructive criticism and feedback on our manuscript.

We will respond to your comments and objections point by point and indicate the changes we propose to the manuscript to address your comments. We have highlighted the changes to the manuscript in red.

1.Selection of the patient's position during TKA surgery is a complex issue that involves a combination of considerations, including aseptic requirements, assistant's position, surgical convenience, and other complex factors in addition to the surgeon's ergonomic evaluation considerations.

Of course, the authors agree that the choice of the position in which the surgeon is positioned during surgery is not based solely on ergonomic positioning criteria. We do not intend to highlight any one position as the only valid position. We have only intended to study and evaluate the position that offers the greatest ergonomic safety for the orthopaedic surgeon and that allows him to perform his operations with the least risk of presenting musculoskeletal disorders related to his work activity. However, your statement is true, and we have considered it as a limitation of the study: “factors such as the use of space suits for surgery, the position of the scrub nurse, or the possibility of the assistant surgeon performing the steps most uncomfortable for the main surgeon have not been considered”.

2. Authors need to write more carefully and avoid low-level errors, such as 1.89cm tall patients (line 86) and 200mm long operating table (line 88).

Thank you for your comment. You are right, we need to be more careful. We have fixed the bugs you mentioned.

3.The form of the tables were confusing, and it is recommended that the tables be in the form of a traditional three-line table.

For clarity, and as you suggested, we have changed the tables to a traditional three-line table.

4.The 95% confidence intervals for Tables 3 and 4 were not necessary to show.

Thank you for your suggestion. We thought it might be interesting, but we will simplify the tables to make them more pleasant to read (tables 3 and 4 have been merged).

5.The results were repetitive with the contents of the tables, and it was suggested to streamline them.

Thank you for your feedback. We have simplified the description of the results to avoid repeating the information in the tables in the text of the manuscript.

6. Line 272-302. Variables such as worktable height, rest periods, muscle training, etc. did not appear to be included in this study, and discussion of these appeared to be unnecessary.

Thank you for your feedback. Indeed, the factors you mention were not evaluated in the research. We have simplified how we express them because they are essential factors to consider in the ergonomics of TKA surgery. In isolation, changes in the surgeon’s position are not the only action that needs to be modified to avoid musculoskeletal pathology. It is interesting to mention these aspects and that they should be included in the discussion as factors to be analysed in future studies.

Round 2

Reviewer 1 Report

all the concern were covered in the reviewed version of the manuscript

Reviewer 2 Report

The authors' contribution to the study is much appreciated.