PONE-D-21-07391

Biomechanics of subtrochanteric fracture fixation using short cephalomedullary nails: a Finite element analysis

PLOS ONE

Dear Dr. Yoo,

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Antonio Riveiro Rodríguez, PhD

Academic Editor

PLOS ONE

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2. We noticed you have some minor occurrence of overlapping text with the following previous publication(s), which needs to be addressed:

https://www.injuryjournal.com/article/S0020-1383(19)30476-0/fulltext

In your revision ensure you cite all your sources (including your own works), and quote or rephrase any duplicated text outside the methods section. Further consideration is dependent on these concerns being addressed.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: N/A

Reviewer #2: N/A

Reviewer #3: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This paper presents a comparison of the stress distribution in the implant and surrounding cortical bone that appear after implantation of short cephalomedullary nails to fix subtrochanteric fracture, when changing some variables. These are: the distance of the fracture from the lesser trochanter (0 to 50mm), the fracture gap (1,2 and 3 mm), using 1 or 2 distal screws, and considering normal or osteoporotic bone. This makes a total of 92 FE analyses that are compared in terms of the value and location of the peak von Mises stress.

There are not many works on this specific application. Also, the conclusions are clinically useful, despite the limitations of the models used. The paper is well-written, although too repetitive, clear and well-focused. Also, the methodological approach is sound and sufficiently described.

On the side of the cons, there is nothing new in the methodology. The simplest approach possible (one single reference load, a very simplified and inaccurate description of the femoral supporting boundary conditions, linearly elastic and isotropic properties both for cortical and cancellous bone, a rough reduction of elastic modulus for the osteoporotic bone, simplified contact conditions) has been used. Therefore, the utility of the paper is essentially clinical. Despite the above limitations, and for comparative purpose, as it is the one of this paper, the results are useful and comparable, so the clinical conclusions are reasonably well supported by the results.

The Discussion section is mainly a summary and repetition of the results obtained, and a comparison between them, which is right, but I would have expected a more complete comparison between the conclusions and what is known in clinical practice, that is, I miss a more clinical discussion on the results.

The limitations of the paper are mostly described in the Discussion, except for the effect of boundary conditions, although, since they are distally applied, I do not expect a big influence on the results on the proximal part, especially when talking about comparative results. However, I would like to see the opinion of the authors regarding the possible effect on such results of the limitations described.

As an overall comment, I do not think that supporting such conclusions requires to include in the paper the results of all 96 models analyzed in three tables and in 12 figures (6 of them in supplementary material). It would be sufficient to add only one table with the most representative results and only one figure to illustrate the type of results obtained. With all this, may be a short note would be sufficient.

As a summary, the paper is original and there is a clear clinical contribution in a very specific problem, but, since there is no new method and the main conclusions are clinical, and correspond to a very specific type of surgery, a clinical journal in traumatology or orthopedic surgery would be more appropriate. There, a more clinical approach would be expected, which would enrich the paper.

Reviewer #2: This paper presents the results of the FE-based analysis of the stresses distribution around nails and cortical bones in subtrochanteric fracture models.

The topic is worth investigation. The subject of the article is well suited to PLOSONE journal.

The quality of English communication is very good. This manuscript is very well written, with clear structure and careful explanations throughout, enabling others to replicate these techniques if desired.

In my opinion this manuscript presents innovative methods which may find interest in practical applications.

Globally, each scientific point is well explained. So I feel that this manuscript is acceptable for publication after minor revision.

Abbreviations LT and PVMS in the abstract should be explained for non-specialist readers.

Has mesh sensitivity analysis been performed? If not, how was the size of the elements determined to obtain reliable results.

The quality of the figures in the reviewed file is very poor. Especially the legends of the von Mises stress in Figs. 3-8 are blurry.

Reviewer #3: The paper is suffering from poor writing. the comments are as follow:

1-Line 48, the authors mentioned that 96 models were tested. Please changes to 96 finite element models were simulated.

2- The quality of all figures are low. Please improve it. So I will take my time to explain how can you get a high quality image from ABAQUS: cTRL P///file///increase the quality to 4090.

3- The conclusion is too short.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes: Rohola Rahnavard

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Biomechanics of subtrochanteric fracture fixation using short cephalomedullary nails: a Finite element analysis

PONE-D-21-07391R1

Dear Dr. Yoo,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Antonio Riveiro Rodríguez, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: N/A

Reviewer #2: N/A

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: The authors have addressed all the comments and suggestions I made in the first review. The quality of the article has been significantly improved. I feel that this manuscript is now acceptable for publication.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No