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. 2025 Mar 10;20(3):e0319102. doi: 10.1371/journal.pone.0319102

Effects of pericapsular nerve group block versus local anesthetic infiltration for postoperative analgesia in total hip arthroplasty: A protocol for systematic review and meta-analysis

Lingzhi Rong 1,☯, Tangqi Qin 2,☯, Shoujia Yu 2, Donghang Zhang 3, Yiyong Wei 4,*
Editor: Robert Jeenchen Chen5
PMCID: PMC11893113  PMID: 40063895

Abstract

Introduction

This protocol for a systematic review and meta-analysis aims to provide synthesized evidence to determine whether pericapsular nerve group (PENG) block is superior to local anesthetic infiltration in controlling postoperative pain in total hip arthroplasty.

Methods and analysis

PubMed, EMBASE, Web of science, and the Cochrane library will be systematically searched from their inception to December 30, 2024. Randomized controlled trials (RCTs) that compared the analgesic effects of PENG block with local anesthetic infiltration for total hip arthroplasty will be included. The time to first analgesics requirement (analgesia duration) will be the primary outcome. Secondary outcomes will include the postoperative analgesics consumption over 24 hours, visual analog scale (VAS) scores at rest and movement, and the incidence of adverse effects. Statistical analysis will be conducted by RevMan 5.4 software.

Ethics and dissemination

Ethical approval is not applicable. The results of this study will be publicly published.

PROSPERO registration number

CRD42024590888

Introduction

Total hip arthroplasty is one of the most common types of orthopedic surgeries [1]. Management of postoperative pain is one major challenge after total hip arthroplasty [2]. Local anesthetic infiltration is generally performed near the completion of total hip arthroplasty by injecting long-acting local anesthetics in the surgical wound and surrounding tissues, which is suggested to provide effective pain relief and reduce the opioids consumption [3–5]. Recently, pericapsular nerve group (PENG) block is emerging as a novel technique targeting the sensory branch of the anterior hip capsule, and is gaining popularity to control postoperative pain after total hip arthroplasty [6–8]. Increasing number of RCTs demonstrated that PENG block improves postoperative pain, decrease the analgesics requirement or prolong the time to first analgesia requirement [9–11]. More importantly, PENG block can provide motor-sparing analgesia, which facilitated the functional recovery after total hip arthroplasty [12]. Additionally, the PENG block can be achieved in the supine position, which is particularly convenient for patients with acute hip fractures [13]. Several systematic review and meta-analysis have also indicated that, compared with the placebo or control group, PENG block was effective in controlling postoperative pain, extended analgesia duration, and reduced opioid consumption after total hip arthroplasty [6,14]. Therefore, PENG block is recommended as one important component of multimodal analgesia [12,15]. In 2015, a network meta-analysis has made an indirect comparison of the analgesic effects between PENG block and local anesthetic infiltration for total hip arthroplasty [16]. Recently, several studies have directly compared the analgesic effects of PENG block and local anesthetic infiltration for total hip arthroplasty [10,17–20], but the results are conflicting. To the best of our knowledge, no systematic review and meta-analysis that directly compare the analgesic effects of PENG block with local anesthetic infiltration has yet been published. Therefore, it is worthwhile to perform a systematic review and meta-analysis to determine whether PENG block is superior to local anesthetic infiltration in postoperative analgesia for total hip arthroplasty.

Methods and analysis

Study registration

We have registered this protocol in the International Prospective Register of Systematic Reviews (CRD42024590888). This study was constructed in line with the Preferred Reporting Items for Systematic Evaluation and Meta-Analysis Protocols (PRISMA-P) guidelines. The PRISMA-P-checklist is described in S1 File. Ethical approval is not applicable.

Search strategy

Two independent authors will systematically search four databases including PubMed, EMBASE, Web of science, and the Cochrane library with the following key terms: “pericapsular nerve group block”, “local anesthetic infiltration”, “local infiltration analgesia”, “total hip arthroplasty”, and “randomized controlled trials”. The search time will be set from their inception to December 30, 2024. The language will be restricted to English. The search plan for all databases was presented in S2 File.

Inclusion and exclusion criteria

Inclusion criteria: 1) Study type: RCTs; 2) Participants: patients underwent total hip arthroplasty; 3) Interventions: pericapsular nerve group block; 4) Control: local anesthetic infiltration; 5) Primary outcomes: the time to first analgesics requirement (analgesia duration); Secondary outcomes: postoperative analgesics consumption over 24 hours, visual analog scale (VAS) scores at rest and movement, and the incidence of adverse effects. Studies do not meet above-mentioned criteria will be excluded, which include the following study types: retrospective studies, systematic review and meta-analysis, narrative reviews, conference abstracts, case reports, comments, letters, perspectives, insights, correspondences, and editorials. Moreover, in order to further optimize the quality of included studies, studies with an extremely small sample size or extremely low quality or unavailable full-text, and repeatedly published studies will be excluded.

Study selection

Firstly, two independent authors will read the titles and abstracts of initially identified studies. Then, the full text of potentially relevant studies will be reviewed for inclusion. When we encountered a study with incomplete information during the study selection process, we will contact the authors for additional information to determine whether the study meet the inclusion criteria. Disagreements will be solved by discussion with a third author. The detailed process for study selection was presented in Fig 1.

Fig 1. The flowchart of study selection.

Fig 1

Open in a new tab

Data extraction

Two independent authors will perform data extraction from the included studies, including published date, regions, characteristics of patients, sample number, anesthesia type, local anesthetics, adjuvants, comparisons, and outcomes. Any discrepancy will be solved by discussion with a third author.

Risk of bias assessment

Two independent authors will perform the risk of bias assessment for included studies using the Cochrane Collaboration’s tool. The risk of bias will be rated as ‘unclear’, ‘low’ or ‘high’ according to the estimated results of six items, including random sequence generation (selection bias), allocation concealment (selection bias), blinding of participants and personnel (performance bias), blinding of outcome assessment (detection bias), incomplete outcome data (attrition bias), and selective reporting (reporting bias). Disagreements will be solved by discussion with a third author.

Statistical analysis

RevMan 5.4 will be used to perform the statistical analysis. Mean differences (MD) and risk ratios (RR) with 95% confidence intervals (CI) will be used for continuous and dichotomous variables, respectively. Statistical heterogeneity will be calculated by I2 test. The fixed-effect model will be applied when I2 <  50%. The random-effect model will be used when I2 >  50%. P <  0.05 represents statistical significance.

Subgroup analysis

If I2 >  50%, subgroup analysis will further be performed to explore the source of heterogeneity based on several potential factors, such as types of participants, types of local anesthetics, the definition of primary outcomes, the combination drugs, language restrictions, etc. A meta-analysis will be performed and the summary effects will be computed within subgroups. According to the results of subgroups, we can recommend a preferred analgesia method for specific conditions.

Sensitivity analysis

Sensitivity analysis will be used to assess the reliability of the pooled results by excluding or including studies based on sample size, methodological quality, or variance. Sensitivity analysis may also explore the impact of using different meta-analysis models. If the pooled results remain consistent across different analyses, the results can be considered reliable. Conversely, the results should be interpreted with caution when an inconsistence exists across sensitivity analyses.

Publication bias

Egger’s test will be used to assess potential publication bias via the funnel plots, which are a scatterplot of each study’s effect size on the x-axis plotted against its standard error on the y-axis. A symmetrical upside-down funnel with smaller studies at the top and more studies at the bottom indicates no publication bias. A skewed funnel indicates publication bias exists, and a ‘trim and fill’ method will be further used to correct the funnel plot asymmetry by 1) removing the smaller studies causing asymmetry, 2) using the trimmed funnel plot to evaluate the true funnel center, and 3) replacing the omitted studies around the funnel center.

Evidence quality assessment

The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach will be used to assess the evidence quality of pooled results and will create a ‘Summary of findings’ table. The GRADE approach will classify the quality of evidence into four levels:

  • High: there is a lot of confidence that the true effect lies close to that of the estimated effect.

  • Moderate: there is moderate confidence in the estimated effect, which means the true effect is likely to be close to the estimated effect, but there is a possibility that it is substantially different.

  • Low: there is limited confidence in the estimated effect, which means the true effect might be substantially different from the estimated effect.

  • Very low: there is very little confidence in the estimated effect, which means the true effect is likely to be substantially different from the estimated effect.

Detailed information could be found in Cochrane handbook (https://training.cochrane.org).

Patient and public involvement

Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

Discussion

Although increasing numbers of studies have compared the effects of PENG block with local anesthetic infiltration on postoperative pain for total hip arthroplasty, no meta-analysis has yet provided synthesized evidence. This study aimed to provide a protocol to determine whether PENG block is superior to local anesthetic infiltration in controlling postoperative pain for total hip arthroplasty. There might be several limitations when conducting this meta-analysis. First, substantial heterogeneity between included studies resulting from the type of local anesthetics, the definition of primary outcomes, the combination drugs, regional differences regarding medical levels and patients’ characteristics, differences in follow-up time, etc., will influence the reliability of pooled results. Second, the number of RCTs that directly compared the effects of PENG block to local anesthetic infiltration might be small. Finally, publication bias might exist because the English language restriction. To minimize the influence of heterogeneity, subgroup analysis will be used to explore their source, and sensitivity analysis will be performed to assess the reliability of pooled data. For subsequent studies, it’s better to include patients with similar baselines, including medical levels, characteristics, and follow-up time, etc. Furthermore, the GRADE approach will be conducted to rank the evidence quality for major outcomes. This protocol has been registered in the PROSPERO and was generated according to the PRISMA-P guidelines.

Exploratory Data Analysis might be performed when encountering unexpected patterns or variations in outcomes. For example, different types of analgesics might be used across included studies, and we will unify the analgesic consumption to morphine equivalent consumption according to the methods described in previous papers (e.g., morphine 1 mg, iv. =  tramadol 10 mg, iv. =  fentanyl 10 mcg, iv. =  sufentanil 1 mcg, iv =  pethidine 10 mg, iv =  oxycodone 1.5 mg, oral) [21,22]. For data that presented using the median and range, we will convert them to the mean and standard deviation [23]. If there were two interventions groups in one included study, we will combine them into one intervention group (Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0.). If pain scores were not reported clearly at rest or on movement, we will contact the authors.

Strengths and limitations of this study

  • This protocol has been registered in the PROSPERO and was generated according to the PRISMA-P guidelines.

  • Two authors will independently perform the databases search, study selection, data extraction, and risk of bias assessment.

  • Substantial heterogeneity might exist between included studies resulting from the type of local anesthetics, the definition of primary outcomes, the combination drugs, etc.

  • Publication bias might exist because the English language restriction.

  • Subgroup analysis and sensitivity analysis will be used to explore the source of heterogeneity, and the GRADE approach will be conducted to rank the evidence quality for major outcomes.

Supporting information

S1 File. The PRISMA-P-checklist.

(DOC)

pone.0319102.s001.doc (74.5KB, doc)
S2 File. Search strategy for all databases.

(DOCX)

pone.0319102.s002.docx (16.3KB, docx)

Data Availability

No datasets were generated or analysed during the current study. All relevant data from this study will be made available upon study completion.

Funding Statement

This work was supported by the Guangdong Basic and Applied Basic Research Foundation (grant No. 2024A1515012880, YW). This funder contributed to the study conceptualization, validation, manuscript writing and editing.

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Decision Letter 0

Robert Chen

4 Nov 2024

PONE-D-24-45094Effects of pericapsular nerve group block versus local anesthetic infiltration for postoperative analgesia in total hip arthroplasty: a protocol for systematic review and meta-analysisPLOS ONE

Dear Dr. Wei,

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Reviewer #1: Yes

Reviewer #2: Partly

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2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses?

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Reviewer #1: Yes

Reviewer #2: No

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Reviewer #2: Yes

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Reviewer #1: 1) The manuscript outlines a rationale by highlighting the conflicting results in existing studies regarding the efficacy of pericapsular nerve group (PENG) block versus local anesthetic infiltration for postoperative pain control in total hip arthroplasty. The study aims to perform a systematic review and meta-analysis to synthesize available evidence, addressing a significant gap in the literature and contributing to the optimization of pain management strategies in orthopedic surgery. A similar meta analysis comparing placebo Vs LIA vs PENG was done previously in 2016.

(Jiménez-Almonte, et. al, Is Local Infiltration Analgesia Superior to Peripheral Nerve Blockade for Pain Management After THA: A Network Meta-analysis. Clinical Orthopaedics and Related Research 474(2):p 495-516, February 2016. | DOI: 10.1007/s11999-015-4619-9)

2) The protocol outlines appropriate databases and search strategies, including clear inclusion and exclusion criteria. The study design aligns with PRISMA-P guidelines, ensuring methodological rigor. However, potential limitations, such as language restrictions and variations in analgesic types and outcome definitions, may impact the reliability of results. These aspects are acknowledged but could benefit from a more comprehensive strategy for mitigating bias.

3) The methodology includes detailed criteria for study selection, data extraction, and statistical analysis. The protocol specifies the use of established tools (e.g., RevMan 5.4) for meta-analysis, risk assessment methods, and criteria for handling heterogeneity. The detailed approach enhances reproducibility.

4) The manuscript states that no datasets were generated during the protocol’s development and that relevant data will be available upon study completion. However, it does not specify the exact repository or access details for data sharing, which is required for transparency and compliance with data availability policies.

5) The protocol is clearly written, with standard scientific English and minimal typographical errors. The structure follows accepted guidelines for study protocols, enhancing readability and comprehension.

6) The manuscript provides a solid foundation for a systematic review and meta-analysis aimed at resolving discrepancies in postoperative analgesia strategies for total hip arthroplasty.

However, there are a few areas for improvement:

a) Data Availability: Specify the repository and data access policies to ensure transparency.

b) Mitigation of Bias: Address limitations related to language restrictions and heterogeneity more comprehensively, potentially by planning subgroup analyses or sensitivity checks.

c) Exploratory Aspects: Consider discussing how exploratory analyses will be handled, particularly if unexpected patterns or variations in outcomes are found.

Overall, the study protocol appears fair, with potential to contribute good insights into pain management techniques for orthopedic surgery.

Reviewer #2: 1. This research has a certain degree of innovation and has certain reference value for clinical practice. However, the manuscript is very brief and there are few references. It is recommended to further enrich the content. For example, subgroup analysis, sensitivity analysis, publication bias analysis, and the method of GRADE assessment of quality grades should be introduced in detail in separate paragraphs.

2. Please describe in detail what you did when you encountered a study with incomplete information during the study selection process, such as whether you tried to determine whether it met the inclusion criteria by obtaining more information, such as contacting the authors.

3. Please provide the retrieval formula construction process for each database, not just an example of the PubMed retrieval plan, to demonstrate the comprehensiveness and scientific nature of the retrieval.

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Reviewer #1: Yes:  Syed Azfar

Reviewer #2: No

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PLoS One. 2025 Mar 10;20(3):e0319102. doi: 10.1371/journal.pone.0319102.r003

Author response to Decision Letter 1

8 Nov 2024

Responses to Reviewers/Editor Letter for revision of PONE-D-24-45094

Dear Dr. Robert Jeenchen Chen and Reviewers (Dr. Syed Azfar and reviewer #2),

Thank you very much for giving us the opportunity to revise our manuscript (PONE-D-24-45094). We appreciate the helpful feedback from you and the reviewers. After carefully reading the comments, we have revised the manuscript point-by-point. Herewith we resubmit a revised manuscript for your assessment. Important changes are highlighted, and detailed responses to each comment are included below. We believe that these revisions have substantially improved the manuscript, and we thank you and the reviewers for their thoughtful comments, which are really helpful for the improvement. All authors of the manuscript have read the revised manuscript prior to re-submission and agree with its contents.

We greatly appreciate your consideration of our manuscript and look forward to hearing from you and reviewers.

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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

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

Response: Thank you! We have checked our manuscript and ensure it meets PLOS ONE's style requirements.

2. Thank you for stating the following financial disclosure:

"This work was supported by the Guangdong Basic and Applied Basic Research Foundation (grant No. 2024A1515012880, YW)."

Please state what role the funders took in the study. If the funders had no role, please state: ""The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.""

If this statement is not correct you must amend it as needed.

Please include this amended Role of Funder statement in your cover letter; we will change the online submission form on your behalf.

Response: Thank you! We have stated what role the funders took in the study (page 11, line 12-14).

Reviewers' comments:

Reviewer #1: 1) The manuscript outlines a rationale by highlighting the conflicting results in existing studies regarding the efficacy of pericapsular nerve group (PENG) block versus local anesthetic infiltration for postoperative pain control in total hip arthroplasty. The study aims to perform a systematic review and meta-analysis to synthesize available evidence, addressing a significant gap in the literature and contributing to the optimization of pain management strategies in orthopedic surgery. A similar meta analysis comparing placebo Vs LIA vs PENG was done previously in 2016.

(Jiménez-Almonte, et. al, Is Local Infiltration Analgesia Superior to Peripheral Nerve Blockade for Pain Management After THA: A Network Meta-analysis. Clinical Orthopaedics and Related Research 474(2):p 495-516, February 2016. | DOI: 10.1007/s11999-015-4619-9)

Response: Thank you very much for this encouraging comments. In this revision, we have described and cited this study (PMID: 26573322) in this revision (page 4, line 20-22).

2) The protocol outlines appropriate databases and search strategies, including clear inclusion and exclusion criteria. The study design aligns with PRISMA-P guidelines, ensuring methodological rigor. However, potential limitations, such as language restrictions and variations in analgesic types and outcome definitions, may impact the reliability of results. These aspects are acknowledged but could benefit from a more comprehensive strategy for mitigating bias.

Response: We thank the reviewer for this good comment. We completely agree with the reviewer that these potential limitations, including language restrictions and variations in analgesic types and outcome definitions will impact the reliability of combined results. Subgroup analysis will further be performed to explore the source of heterogeneity, and sensitivity analysis will be performed to test the reliability of combined results. We have described this and provided more information for mitigating bias (page 8, line 4-18).

3) The methodology includes detailed criteria for study selection, data extraction, and statistical analysis. The protocol specifies the use of established tools (e.g., RevMan 5.4) for meta-analysis, risk assessment methods, and criteria for handling heterogeneity. The detailed approach enhances reproducibility.

Response: Thank you very much for this encouraging comments.

4) The manuscript states that no datasets were generated during the protocol’s development and that relevant data will be available upon study completion. However, it does not specify the exact repository or access details for data sharing, which is required for transparency and compliance with data availability policies.

Response: Thank you for this nice comment. For this protocol, no datasets have been generated and/or analyzed. When the related meta-analysis of this protocol is finished, we will submit the results and data to one peer-reviewed journal and published it publicly. We have made a Data Availability Statement in this revision (page 11, line 19-24).

5) The protocol is clearly written, with standard scientific English and minimal typographical errors. The structure follows accepted guidelines for study protocols, enhancing readability and comprehension.

Response: Thank you very much.

6) The manuscript provides a solid foundation for a systematic review and meta-analysis aimed at resolving discrepancies in postoperative analgesia strategies for total hip arthroplasty.

Response: Thank you very much for this nice comment.

However, there are a few areas for improvement:

a) Data Availability: Specify the repository and data access policies to ensure transparency.

Response: Thank you. We have specified the repository and data access policies to ensure transparency (page 11, line 19-24).

b) Mitigation of Bias: Address limitations related to language restrictions and heterogeneity more comprehensively, potentially by planning subgroup analyses or sensitivity checks.

Response: Thank you very much for this helpful suggestion. We have described how to address limitations related to language restrictions and heterogeneity more comprehensively by planning subgroup analyses and sensitivity analysis (page 8, line 4-18).

c) Exploratory Aspects: Consider discussing how exploratory analyses will be handled, particularly if unexpected patterns or variations in outcomes are found.

Response: Thank you very much. We have discussed how exploratory analyses will be handled as “Exploratory Data Analysis might be performed when encountering unexpected patterns or variations in outcomes. For example, different types of analgesics might be used across included studies, and we will unify the analgesic consumption to morphine equivalent consumption according to the methods described in one previous paper (PMID: 18574361). For data that presented using the median and range, we will convert them to the mean and standard deviation (PMID: 15840177). If there were two interventions groups in one included study, we will combine them into one intervention group (Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0.). If pain scores were not reported clearly at rest or on movement, we will contact the authors.” (page 10, line 18-26).

Overall, the study protocol appears fair, with potential to contribute good insights into pain management techniques for orthopedic surgery.

Response: Thank you very much for your valuable comments, which have substantially improved our manuscript.

Reviewer #2: 1. This research has a certain degree of innovation and has certain reference value for clinical practice. However, the manuscript is very brief and there are few references. It is recommended to further enrich the content. For example, subgroup analysis, sensitivity analysis, publication bias analysis, and the method of GRADE assessment of quality grades should be introduced in detail in separate paragraphs.

Response: Thank you very much. We have added detailed information for subgroup analysis, sensitivity analysis, publication bias analysis, and the GRADE methods (page 8, line 4-28; page 9, line 1-14). Moreover, we have described how to handle unexpected patterns or variations in outcomes (page 10, line 18-26) and added more references as recommended (page 4, line 7, 9, 20 and 22).

2. Please describe in detail what you did when you encountered a study with incomplete information during the study selection process, such as whether you tried to determine whether it met the inclusion criteria by obtaining more information, such as contacting the authors.

Response: Thank you very much for this good question. When we encountered a study with incomplete information during the study selection process, we will contact the authors for additional information to determine whether the study meet the inclusion criteria. We have described this (page 7, line 3-5). Furthermore, we have described how to handle unexpected patterns or variations in outcomes (page 10, line 18-26)

3. Please provide the retrieval formula construction process for each database, not just an example of the PubMed retrieval plan, to demonstrate the comprehensiveness and scientific nature of the retrieval.

Response: Thank you for this helpful suggestion. We have included the full search strategy for all databases in a supplementary file (S2_File). Accordingly, this supplementary file has be cited in the main text (page 6, line 15).

Attachment

Submitted filename: Response to Reviewers.docx

pone.0319102.s004.docx (22.5KB, docx)

Decision Letter 1

Robert Chen

20 Nov 2024

PONE-D-24-45094R1Effects of pericapsular nerve group block versus local anesthetic infiltration for postoperative analgesia in total hip arthroplasty: a protocol for systematic review and meta-analysisPLOS ONE

Dear Dr. Wei,

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 revise.

Please submit your revised manuscript by Jan 04 2025 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: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Robert Jeenchen Chen, MD, MPH

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

The research question outlined is expected to address a valid academic problem or topic and contribute to the base of knowledge in the field.

Reviewer #1: Yes

Reviewer #2: Yes

**********

2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses?

The manuscript should describe the methods in sufficient detail to prevent undisclosed flexibility in the experimental procedure or analysis pipeline, including sufficient outcome-neutral conditions (e.g. necessary controls, absence of floor or ceiling effects) to test the proposed hypotheses and a statistical power analysis where applicable. As there may be aspects of the methodology and analysis which can only be refined once the work is undertaken, authors should outline potential assumptions and explicitly describe what aspects of the proposed analyses, if any, are exploratory.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable?

Descriptions of methods and materials in the protocol should be reported in sufficient detail for another researcher to reproduce all experiments and analyses. The protocol should describe the appropriate controls, sample size calculations, and replication needed to ensure that the data are robust and reproducible.

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception, at the time of publication. 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 and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

(Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Please accept revised version of submission. As most of the points are well taken and revised as per suggestions.

Reviewer #2: Appreciate the efforts of the authors. The manuscript has been well revised, but there are still some issues that need to be addressed.

1. The description of the exclusion criteria could be more detailed. For example, in addition to the studies that do not meet the inclusion criteria, whether certain specific types of studies are also excluded (such as those with an extremely small sample size or extremely low quality), and the specific reasons for the exclusion. Consider whether it is necessary to set some additional exclusion criteria, such as studies that have been repeatedly published, studies for which the full text cannot be obtained, etc., in order to further optimize the quality of the included studies.

2. If publication bias is found to exist, what measures will be taken to adjust or explain it? For example, conducting a trim-and-fill analysis or exploring the extent to which publication bias affects the research results, so as to enhance the credibility of the research results.

3. Discussion Section.

In addition to the limitations already mentioned, other factors that may affect the research results can also be considered, such as regional differences in the research (the medical level and patient characteristics may vary in different regions), differences in follow-up time (the assessment of long-term analgesic effects and complications may be insufficient), etc., and discuss how to make improvements in subsequent studies.

You mentioned in the text that the usage amount of analgesics will be uniformly converted into the morphine equivalent usage amount. Please elaborate on how you will carry out this conversion.

**********

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.

PLoS One. 2025 Mar 10;20(3):e0319102. doi: 10.1371/journal.pone.0319102.r005

Author response to Decision Letter 2

23 Nov 2024

Responses to Reviewers/Editor Letter for revision of PONE-D-24-45094R1

Dear Dr. Robert Jeenchen Chen and Reviewers,

Thank you very much for giving us the opportunity to revise our manuscript (PONE-D-24-45094R1). We appreciate the helpful feedback from you and the reviewers. After carefully reading the comments, we have revised the manuscript point-by-point. Herewith we resubmit a revised manuscript for your assessment. Important changes are highlighted, and detailed responses to each comment are included below. We believe that these revisions have substantially improved the manuscript, and we thank you and the reviewers for their thoughtful comments, which are really helpful for the improvement. All authors of the manuscript have read the revised manuscript prior to re-submission and agree with its contents.

We greatly appreciate your consideration of our manuscript and look forward to hearing from you and reviewers.

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Response: Thank you! We have checked the reference list to ensure that it is complete and correct.

Reviewers' comments:

Reviewer #1: Please accept revised version of submission. As most of the points are well taken and revised as per suggestions.

Response: Thank you very much for your valuable comments, which have substantially improved our manuscript.

Reviewer #2: Appreciate the efforts of the authors. The manuscript has been well revised, but there are still some issues that need to be addressed.

1. The description of the exclusion criteria could be more detailed. For example, in addition to the studies that do not meet the inclusion criteria, whether certain specific types of studies are also excluded (such as those with an extremely small sample size or extremely low quality), and the specific reasons for the exclusion. Consider whether it is necessary to set some additional exclusion criteria, such as studies that have been repeatedly published, studies for which the full text cannot be obtained, etc., in order to further optimize the quality of the included studies.

Response: We thank the reviewer for these nice suggestions. We have added this information in the manuscript as “Studies do not meet above-mentioned criteria will be included, which include the following study types: retrospective studies, systematic review and meta-analysis, narrative reviews, conference abstracts, case reports, comments, letters, perspectives, insights, correspondences, and editorials. Moreover, in order to further optimize the quality of included studies, studies with an extremely small sample size or extremely low quality or unavailable full-text, and repeatedly published studies will be excluded.” (page 6, line 26-28; page 7, line 1-3).

2. If publication bias is found to exist, what measures will be taken to adjust or explain it? For example, conducting a trim-and-fill analysis or exploring the extent to which publication bias affects the research results, so as to enhance the credibility of the research results.

Response: Thank you very much for this good question. We have described how to handle publication bias as “A skewed funnel indicates publication bias exists, and a ‘trim and fill’ method will be further used to correct the funnel plot asymmetry by 1) removing the smaller studies causing asymmetry, 2) using the trimmed funnel plot to evaluate the true funnel center, and 3) replacing the omitted studies around the funnel center.” (page 9, line 1-5).

3. Discussion Section.

In addition to the limitations already mentioned, other factors that may affect the research results can also be considered, such as regional differences in the research (the medical level and patient characteristics may vary in different regions), differences in follow-up time (the assessment of long-term analgesic effects and complications may be insufficient), etc., and discuss how to make improvements in subsequent studies.

Response: Thank you very much for pointing out this issue. We completely agree with the reviewer that other factors that may affect the research results, such as regional differences and differences in follow-up time, we have added this information. Subgroup group analysis and sensitivity analysis will be further conducted to identify their influence on the pooled results. For subsequent studies, it’s better to include patients with similar medical levels, characteristics, and follow-up time. We have discussed this issue in the revision (page 10, line 9-10, line 13-17).

You mentioned in the text that the usage amount of analgesics will be uniformly converted into the morphine equivalent usage amount. Please elaborate on how you will carry out this conversion.

Response: Thank you very much. We have provided the conversion formula for commonly used analgesics and cited the relevant references (page 10, line 24-26).

Finally, thank you again for your great help in improving our manuscript.

Attachment

Submitted filename: Response_to_Reviewers_auresp_2.docx

pone.0319102.s005.docx (17.3KB, docx)

Decision Letter 2

Robert Chen

9 Dec 2024

PONE-D-24-45094R2Effects of pericapsular nerve group block versus local anesthetic infiltration for postoperative analgesia in total hip arthroplasty: a protocol for systematic review and meta-analysisPLOS ONE

Dear Dr. Wei,

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 revise.

Please submit your revised manuscript by Jan 23 2025 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: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Robert Jeenchen Chen, MD, MPH, ChFC®, EA, CLU

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

The research question outlined is expected to address a valid academic problem or topic and contribute to the base of knowledge in the field.

Reviewer #3: Yes

Reviewer #4: Partly

**********

2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses?

The manuscript should describe the methods in sufficient detail to prevent undisclosed flexibility in the experimental procedure or analysis pipeline, including sufficient outcome-neutral conditions (e.g. necessary controls, absence of floor or ceiling effects) to test the proposed hypotheses and a statistical power analysis where applicable. As there may be aspects of the methodology and analysis which can only be refined once the work is undertaken, authors should outline potential assumptions and explicitly describe what aspects of the proposed analyses, if any, are exploratory.

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable?

Descriptions of methods and materials in the protocol should be reported in sufficient detail for another researcher to reproduce all experiments and analyses. The protocol should describe the appropriate controls, sample size calculations, and replication needed to ensure that the data are robust and reproducible.

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception, at the time of publication. 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 #3: Yes

Reviewer #4: 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 #3: No

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

(Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #3: Thank you very much for allowing me to review your manuscript. I appreciate your effort in performing this study and submitting it to plos one. I would like to point out a few things that should be corrected:

1) I assume the author should rewrite the inclusion part in a better format. In addition, you add a sentence that should change it. You wrote: “Studies do not meet above-mentioned criteria will be included”. I think you wanted to write excluded instead of included.

2) The PRISMA chart you included is a template and I cannot see the number of studies you included or excluded in your PRISMA chart.

3) Your discussion part is too short. Please extend it.

Reviewer #4: The efforts of the authors is praiseworthy.

Kindly shorten the introduction section of abstract. It is lengthy.

**********

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 #3: No

Reviewer #4: 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.

PLoS One. 2025 Mar 10;20(3):e0319102. doi: 10.1371/journal.pone.0319102.r007

Author response to Decision Letter 3

11 Dec 2024

Responses to Reviewers/Editor Letter for revision of PONE-D-24-45094R2

Dear Dr. Robert Jeenchen Chen and Reviewers,

Thank you very much for giving us the opportunity to revise our manuscript (PONE-D-24-45094R2). We appreciate the helpful feedback from you and the reviewers. After carefully reading the comments, we have revised the manuscript point-by-point. Herewith we resubmit a revised manuscript for your assessment. Important changes are highlighted, and detailed responses to each comment are included below. We believe that these revisions have substantially improved the manuscript, and we thank you and the reviewers for their thoughtful comments, which are really helpful for the improvement. All authors of the manuscript have read the revised manuscript prior to re-submission and agree with its contents.

We greatly appreciate your consideration of our manuscript and look forward to hearing from you and reviewers.

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Response: Thank you! We have checked the reference list to ensure that it is complete and correct.

Reviewers' comments:

Reviewer #3: Thank you very much for allowing me to review your manuscript. I appreciate your effort in performing this study and submitting it to plos one. I would like to point out a few things that should be corrected:

1) I assume the author should rewrite the inclusion part in a better format. In addition, you add a sentence that should change it. You wrote: “Studies do not meet above-mentioned criteria will be included”. I think you wanted to write excluded instead of included.

Response: Thank you very much for your valuable comments. During last revision stage, we have updated the inclusion and exclusion criteria as “Inclusion criteria: 1) Study type: RCTs; 2) Participants: patients underwent total hip arthroplasty; 3) Interventions: pericapsular nerve group block; 4) Control: local anesthetic infiltration; 5) Primary outcomes: the time to first analgesics requirement (analgesia duration); Secondary outcomes: postoperative analgesics consumption over 24 hours, visual analog scale (VAS) scores at rest and movement, and the incidence of adverse effects. Studies do not meet above-mentioned criteria will be excluded, which include the following study types: retrospective studies, systematic review and meta-analysis, narrative reviews, conference abstracts, case reports, comments, letters, perspectives, insights, correspondences, and editorials. Moreover, in order to further optimize the quality of included studies, studies with an extremely small sample size or extremely low quality or unavailable full-text, and repeatedly published studies will be excluded.”. (page 6, line 17-28)

2) The PRISMA chart you included is a template and I cannot see the number of studies you included or excluded in your PRISMA chart.

Response: Thank you very much for this nice question. This meta-analysis has not yet started, therefore, we did not include the number of studies in the PRISMA chart. It is normal for a protocol and is consistent with the journal guidelines of Plos One. Thanks for your understanding.

3) Your discussion part is too short. Please extend it.

Response: Thank you very much. During the revision, we have extended the discussion part as “Although increasing numbers of studies have compared the effects of PENG block with local anesthetic infiltration on postoperative pain for total hip arthroplasty, no meta-analysis has yet provided synthesized evidence. This study aimed to provide a protocol to determine whether PENG block is superior to local anesthetic infiltration in controlling postoperative pain for total hip arthroplasty. There might be several limitations when conducting this meta-analysis. First, substantial heterogeneity between included studies resulting from the type of local anesthetics, the definition of primary outcomes, the combination drugs, regional differences regarding medical levels and patients’ characteristics, differences in follow-up time, etc., will influence the reliability of pooled results. Second, the number of RCTs that directly compared the effects of PENG block to local anesthetic infiltration might be small. Finally, publication bias might exist because the English language restriction. To minimize the influence of heterogeneity, subgroup analysis will be used to explore their source, and sensitivity analysis will be performed to assess the reliability of pooled data. For subsequent studies, it’s better to include patients with similar baselines, including medical levels, characteristics, and follow-up time, etc. Furthermore, the GRADE approach will be conducted to rank the evidence quality for major outcomes. This protocol has been registered in the PROSPERO and was generated according to the PRISMA-P guidelines.

Exploratory Data Analysis might be performed when encountering unexpected patterns or variations in outcomes. For example, different types of analgesics might be used across included studies, and we will unify the analgesic consumption to morphine equivalent consumption according to the methods described in previous papers (e.g., morphine 1 mg, iv. = tramadol 10 mg, iv. = fentanyl 10 mcg, iv. = sufentanil 1 mcg, iv = pethidine 10 mg, iv = oxycodone 1.5 mg, oral). For data that presented using the median and range, we will convert them to the mean and standard deviation. If there were two interventions groups in one included study, we will combine them into one intervention group (Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0.). If pain scores were not reported clearly at rest or on movement, we will contact the authors.”. (page 10-11)

Reviewer #4: The efforts of the authors is praiseworthy.

Response: Thank you very much for your encouraging comment.

Kindly shorten the introduction section of abstract. It is lengthy.

Response: Thank you very much for this helpful suggestion. We have shortened the introduction section of abstract as “This protocol for a systematic review and meta-analysis aims to provide synthesized evidence to determine whether pericapsular nerve group (PENG) block is superior to local anesthetic infiltration in controlling postoperative pain in total hip arthroplasty.”. (page 2, line 2-5)

Finally, thank you again for your great help in improving our manuscript.

Attachment

Submitted filename: Response_to_Reviewers_auresp_3.docx

pone.0319102.s006.docx (18.6KB, docx)

Decision Letter 3

Robert Chen

28 Jan 2025

Effects of pericapsular nerve group block versus local anesthetic infiltration for postoperative analgesia in total hip arthroplasty: a protocol for systematic review and meta-analysis

PONE-D-24-45094R3

Dear Dr. Wei,

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,

Robert Jeenchen Chen, MD, MPH, ChFC®, EA, CLU

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

The research question outlined is expected to address a valid academic problem or topic and contribute to the base of knowledge in the field.

Reviewer #4: Yes

Reviewer #5: Yes

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2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses?

The manuscript should describe the methods in sufficient detail to prevent undisclosed flexibility in the experimental procedure or analysis pipeline, including sufficient outcome-neutral conditions (e.g. necessary controls, absence of floor or ceiling effects) to test the proposed hypotheses and a statistical power analysis where applicable. As there may be aspects of the methodology and analysis which can only be refined once the work is undertaken, authors should outline potential assumptions and explicitly describe what aspects of the proposed analyses, if any, are exploratory.

Reviewer #4: Yes

Reviewer #5: Yes

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3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable?

Descriptions of methods and materials in the protocol should be reported in sufficient detail for another researcher to reproduce all experiments and analyses. The protocol should describe the appropriate controls, sample size calculations, and replication needed to ensure that the data are robust and reproducible.

Reviewer #4: Yes

Reviewer #5: Yes

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4. Have the authors described where all data underlying the findings will be made available when the study is complete?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception, at the time of publication. 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 #4: No

Reviewer #5: Yes

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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 #4: Yes

Reviewer #5: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

(Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #4: Congratulations to the authors for your hard and dedicated work. The paper is supposed to add value to existing literature.

Reviewer #5: I sincerely appreciate the opportunity to review this article. It is not very common to read a protocol for a systematic review or meta-analysis, as protocols are more often written for original research. However, from a methodological point, this protocol is well-structured and appropriate for publication in Plos One, given its clear design and clinical relevance.

The protocol addresses an important comparison in pain management for total hip arthroplasty, a topic of interest in regional anesthesia. The proposed methodology is adequate, with a clear definition of inclusion and exclusion criteria, as well as a well-designed statistical analysis plan.

In my opinion, the article effectively synthesizes the necessary methodological information for this type of study and meets the quality standards required for publication in Plos One.

**********

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Reviewer #4: Yes:  Dr Satish Prasad Barnawal

Reviewer #5: No

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Acceptance letter

Robert Chen

PONE-D-24-45094R3

PLOS ONE

Dear Dr. Wei,

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team.

At this stage, our production department will prepare your paper for publication. This includes ensuring the following:

* All references, tables, and figures are properly cited

* All relevant supporting information is included in the manuscript submission,

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If revisions are needed, the production department will contact you directly to resolve them. If no revisions are needed, you will receive an email when the publication date has been set. At this time, we do not offer pre-publication proofs to authors during production of the accepted work. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few weeks to review your paper and let you know the next and final steps.

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If we can help with anything else, please email us at customercare@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Robert Jeenchen Chen

Academic Editor

PLOS ONE

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    S1 File. The PRISMA-P-checklist.

    (DOC)

    pone.0319102.s001.doc (74.5KB, doc)
    S2 File. Search strategy for all databases.

    (DOCX)

    pone.0319102.s002.docx (16.3KB, docx)
    Attachment

    Submitted filename: Response to Reviewers.docx

    pone.0319102.s004.docx (22.5KB, docx)
    Attachment

    Submitted filename: Response_to_Reviewers_auresp_2.docx

    pone.0319102.s005.docx (17.3KB, docx)
    Attachment

    Submitted filename: Response_to_Reviewers_auresp_3.docx

    pone.0319102.s006.docx (18.6KB, docx)

    Data Availability Statement

    No datasets were generated or analysed during the current study. All relevant data from this study will be made available upon study completion.

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