Transfer Alert

This paper was transferred from another journal. As a result, its full editorial history (including decision letters, peer reviews and author responses) may not be present.

PONE-D-20-13783

Radiographic evaluation of patellar tendon length following corrective surgical procedures for medial patellar luxation in dogs.

PLOS ONE

Dear Dr. de Moya,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jul 26 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Silvia Sabattini

Academic Editor

PLOS ONE

Journal requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. Thank you for including your funding statement; "The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."

At this time, please address the following queries:

1. Please clarify the sources of funding (financial or material support) for your study. List the grants or organizations that supported your study, including funding received from your institution.
2. State what role the funders took in the study. If the funders had no role in your study, please state: “The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”
3. If any authors received a salary from any of your funders, please state which authors and which funders.
4. If you did not receive any funding for this study, please state: “The authors received no specific funding for this work.”

Please include your amended statements within your cover letter; we will change the online submission form on your behalf.

3. Please amend the manuscript submission data (via Edit Submission) to include author Stanley Kim

4. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information.

[Note: HTML markup is below. Please do not edit.]

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

**********

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

Reviewer #1: Yes

Reviewer #2: N/A

**********

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

**********

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

**********

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: Dear Authors, I have been really pleased to review this manuscript. I think patellar luxation is one of the most important disease that any orthopaedic surgeon has to deal with. Although we have a huge kwnoledge of this condition, I belive there is still a lot of to understand to improve our diagnosis, treatment and outcome. For this reason any information that might help reaching this goal is very valuable.

Regarding the study presented here, looking at the changings of the patellar tendon and its effect on the vertical position of the patella, I think this is an interesting point of view that has still not been properly studied.

I don't have many critics to do about the aim of the paper, the statistical analysis and the contents in general. I have given some suggestions to try to improve the text, and I have tried to find potential conflicts that need to be addressed to make the manuscript sound. My biggest critic is regarding references since PL is a quite popular topic in veterinary literature and when I read a paper on this topic I expect to find a lot of scientific support.

I would also consider to find some evidence of the same condition in human literature, it might be interesting for comparing your results.

My general judgment is positive. Following you can find some specific comments. I hope my suggestions will help you in publishing this paper.

COMMENTS:

39 – correct “patellar” to “patella”

40-42 – Mostafa 2008 seems to be the only paper used as reference for this study. See comments later.

47-50 – more references.

50-52 – confusing, reporting some info as on line 40-42

52-54 – this is probably non-relevant information. The paper deals with MPL and any other affection of the stifle lead to exclusion. I would erase it.

54-56 – please discuss, for a better understanding of the Reader, why this can happen.

62-63 – please change “would” to “might”. Your hypothesis is correct from my point of view; however have you considered that some dogs, especially some small breed, can have concomitant MPL and patella baja, and in this case the elongated patellar tendon should improve the tracking and not increase the risk of luxation. Maybe you should specify that the hypothesis is limited to dog with a relatively normal position of the patella.

71 – is 2-3 months an appropriate follow up? Patellar tendon stretching and elongation might take longer, also some complications as reluxation might happen later in time.

71-73 – please remove “from medical records”; correct “include” to “included”; please remove “comorbidities” because you stated previously your inclusion/exclusion criteria; change “surgical procedure(s) and post-operative complications” (let’s follow an appropriate chronologic order)

73 – Please change “Surgical corrective procedures performed include” to “Surgical treatment included”

78 – the reference to the Figure should be moved at the end of the sentence that describes the methodology of measurement.

77-80 – I am not convinced of the first sentence, it does not sound well. I would suggest to change this part as follow “All measurements were performed on a standard mediolateral radiographic projection of the stifle by using a dedicated PACS workstation using DICOM viewing software (Merge Healthcare Inc, Chicago, Illinois).”

80-81 – Can you mention the angle between femur and tibia? Do you think that limb positioning (in this case the degree of flexion) may affect measurement and result? (for replicating your study it is important to give to the Reader all the relevant information).

Maybe this can be helpful: “There was no association between the degree of stifle joint flexion and PLLj/PL and PLLm/PL ratios, respectively” (Łojszczyk-Szczepaniak, A., Silmanowicz, P., Komsta, R. et al. Determination of reference values and frequency of occurrence of patella alta in German shepherd dogs: a retrospective study. Acta Vet Scand 59, 36 (2017). https://doi.org/10.1186/s13028-017-0304-1)

82 – remove “from”, written twice

82-86 – vertical position of the patella in dogs has been previously reported and several methods have been described (for example Mostafa et al. and Johnson et al. described two different measurements). Can you please add a reference to your methodology in order to help the Reader to understand that not all the published studies are comparable between each other?

86-88 – this is a good way to reduce the risk of error. My recommendation for next time for more reliable data is to make repeated measurement and check for intraobserver difference in order to be sure that final number is as much precise as possible.

88 – regarding landmarks, have you noticed any implant interference in identifying the correct landmark? The accuracy of measurement might be discussed.

110 – “On a total of 242 stifles surgically repaired, only 50 cases met the inclusion criteria”. Maybe sounds better.

111 – “The majority of cases were excluded due to inadequate radiographic follow up”. I think you can delete this sentence since you stated previously your inclusion/exclusion criteria.

134 – Here I would mention a sentence that I suggested to remove in the introduction regarding the reported changings following TPLO procedure. I would start the discussion stating that the patellar tendon is subjected to changings and that some pathologies as well treatments can affect its length. Try to find further references (also check human literature) to strengthen this statement because this is the pillar of the paper.

139-142 – Please check the literature, there are papers that provide some information that are in contrast with studies you cited. It is important in the discussion review all the available literature to find evidence. “Additionally, patella alta has previously been proposed as predisposing factor to post-operative recurrence of luxation (Johnson 2006)”, but patella alta has also been observed in healthy dogs that did not exhibit orthopaedic problems in the stifle joints (Łojszczyk-Szczepaniak, A., Silmanowicz, P., Komsta, R. et al. Determination of reference values and frequency of occurrence of patella alta in German shepherd dogs: a retrospective study. Acta Vet Scand 59, 36 (2017)).

If you do not clarify this statements it sounds like that if the patella is alta you can have reluxation. I believe this complication is more related to other abnormalities rather than a patella higher than normal.

Wandagee 2013 reported “The outcome of surgery was considered good for grade II luxation with a 100% success rate. Recurrent medial patellar luxation was diagnosed in approximately 11% of dogs with grade III and in 36% of dogs with grade IV luxation.”

By reading the available literature, we have evidence that risk of reluxation is relatively low and patella alta might not be as relevant as you stated. And reluxation is generally observed in dogs with severe stifle abnormalities (both skeletal and of the soft tissues)

“Previous studies have established that large breed dogs with MPL have a relatively long patellar tendon compared to dogs without stifle disease (Mostafa 2008)”. This statement is correct, but remember that MPL is typically seen in small breed dogs.

160 – Please add more references.

161-167 – This is probably one of the most interesting part of the paper. You must answer this question “Why grade 3-4 MPL have not significantly different ratios?”. This is probably due to the pre-existing elongation of the tendon that is subjected to abnormal tension during growth or normal physical activity.

177-190 – Very good paragraph that answer some of my previous comments. Last sentence in incomplete.

Reviewer #2: Dear authors this topic is very interesting, and the study is well done but some issues must be revised. please find attached the comments.

Comment 1) Please add the name of the second co-author (all co-authors) at the beginning, in the "Order of Authors".

Comment 2) According to the journal guidelines, the references should be cited as the numbers in brackets. They should be numbered in the order they appear in the text. Please revise your citations.

Comment 3) According to the journal guidelines, the abstracts should not include abbreviations if it is possible.

Comment 4) Line 39: Please revise the words "patellar alta" to "patella alta".

Comment 5) Line 68-69: You did not talk about LPL in your study. Please explain if you excluded the dogs with LPL from your study. If LPL affected dogs were not excluded please explain the dogs with MPL and LPL. Is there any relationship between the dogs with bidirectional patellar luxation and post-operative patellar tendon length?

Comment 6) Please talk about the muscle contracture in your study and if the radiographs were taken under general anesthesia.

Comment 7) Lines 84 – 85. Please revise the sentence "the distance from the distal most aspect of the patellar to the proximal aspect of the tibial tuberosity" as "the distance from the most distal aspect of the patella to the most proximal aspect of the tibial tuberosity".

Comment 8) Lines 93 - 94. Please revise the sentence "Patella tendon: patellar ratio" as "Patellar tendon length: patellar length ratio".

Comment 9) Please include the name and version of the used statistical software and calculation methods (name of the tests) in the material and methods.

Comment 10) Please discuss the included dog breeds in your study. You only mentioned in the discussion that you had small to large breed dogs; it would not be out of interest if you could explain the frequency of each breed.

Comment 11) Line 158. You are talking about post-operative complications reported in the literature. Did you have any post-operative complications in included dogs? Please discuss it.

Comment 12) Line 185. Please discuss the level of experience of the observer who measured the alignments. Did the observer train to measure alignments before the study?

Comment 13) Line 190. The sentence "another limitation of the study was" is incomplete, please delete it.

Best regards

**********

6. 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

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PONE-D-20-13783R1

Radiographic evaluation of patellar tendon length following corrective surgical procedures for medial patellar luxation in dogs.

PLOS ONE

Dear Dr. Kim,

Thank you for submitting your manuscript to PLOS ONE and for this revised version. The reviewers have raised a few minor criticisms that can be easily addressed prior to publication.

Please submit your revised manuscript by Sep 26 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Silvia Sabattini

Academic Editor

PLOS ONE

[Note: HTML markup is below. Please do not edit.]

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: (No Response)

**********

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: Yes

**********

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: Thank you for this revised version of the paper. All the previous comments have been addressed and now the paper is sound.

Minor comments:

23 - at least 1 month follow up; line 69, 108 is 2-3 months follow up. Although you say in the abstract "at least one month" and it is possible that none of the patients had only 1 month fu, it sounds strange. You could change in the text "2-3 months fu" with "the last fu" since doesn't matter if it is 2-3 months or longer or a bit lesser because in the inclusion criteria you stated "at least one month fu".

147 – change long to longer

206-207 – please cite the study

Reviewer #2: Dear Authors,

Thank you very much for submitting the revised manuscript. I do see that the requested edits were made and submitted successfully in the Editorial Manager. However, there are still some outstanding issues that must be resolved. Please revise the following parts.

Line 83) Please revise the word ''patellar'' to the ''patella''.

Line 178) Please revise the word ''glad'' to the word ''grade''.

Kind regards

**********

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

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Radiographic evaluation of patellar tendon length following corrective surgical procedures for medial patellar luxation in dogs.

PONE-D-20-13783R2

Dear Dr. Kim,

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.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Silvia Sabattini

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: