Measurement of Compression Forces During Spinal Fusion Surgery Utilizing the Proprioceptive Effect of Hand Muscle Memory

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I have provided the authors with comments in a PDF file. Major revision 11 comments. 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript addresses an underexplored yet clinically relevant issue by attempting to quantify and standardize intraoperative compression forces during lumbar interbody fusion procedures. While the study is innovative and provides preliminary reference values, several methodological concerns warrant attention.

1. Experimental Model Limitations

Phase 1 relied on a 3D-printed spine model to simulate endplate biomechanics. However, such models lack the viscoelastic and anisotropic properties of native vertebral endplates, thereby limiting the ecological validity of the derived compression thresholds. The authors should discuss to what extent the results can be extrapolated to in vivo surgical conditions and whether any adjustments were made to approximate physiological endplate stiffness.

Question: Could the authors clarify whether material properties of the printed model were validated against cadaveric bone to ensure biomechanical comparability?

2. Study Population Composition

The Phase 1 cohort included both clinical and non-clinical participants. While this demonstrates general proprioceptive ability, it also dilutes the relevance to surgical practice. Highly trained surgeons may exhibit distinct motor memory or force application strategies.

Question: What proportion of participants were trained spinal surgeons, and were their results analyzed separately to highlight differences in reproducibility compared to non-clinicians?

3. Indirect Measurement of Intraoperative Forces

Due to regulatory constraints, intraoperative forces were not measured directly at the implant–endplate interface. Instead, the study used a proprioceptive recall method with a hand dynamometer. Although reproducible, this method introduces potential recall bias and does not reflect the true force transmitted through the implant.

Question: Do the authors plan to validate this surrogate method against direct intraoperative force sensors once regulatory approval permits? Without such validation, the clinical reliability of the proposed reference values remains uncertain.

4. Statistical Analysis Approach

The analysis relied exclusively on descriptive statistics, without inferential testing, hypothesis-driven comparisons, or power calculations. This restricts the ability to draw robust conclusions, particularly regarding inter-surgeon variability, time-dependent reproducibility, or segment-specific effects.

Question: Could the authors justify the absence of inferential statistics and clarify whether exploratory comparisons (e.g., between vertebral levels or surgeons) were attempted but not reported?

5. Lack of Clinical Correlation

The study does not evaluate clinical outcomes such as fusion rates, subsidence, or patient-reported outcome measures. As a result, it remains unknown whether the identified force ranges are beneficial, neutral, or potentially harmful.

Question: When designing the planned prospective trial, how do the authors intend to correlate compression forces with radiographic and functional outcomes to establish clinically meaningful benchmarks?

Overall Recommendation

The study presents an important first step toward standardizing intraoperative compression forces. However, its conclusions are constrained by simulation-based models, indirect measurement methods, and absence of hypothesis-driven statistical analysis. Clarification of the above points and stronger justification of methodological choices are required before the findings can be interpreted as reliable clinical guidance.

Comments on the Quality of English Language

The overall quality of the English language in the manuscript is acceptable and the text is largely comprehensible. The authors have clearly made efforts to refine linguistic clarity and maintain readability. Nevertheless, there remain several areas where phrasing could be improved to enhance precision, fluency, and alignment with standard scientific writing conventions.

• Consistency of terminology: Certain terms (e.g., “force recall,” “dummy model,” “reproducibility”) could be expressed in more standardized biomechanical or clinical terminology to avoid ambiguity.

• Word choice and register: Some expressions (e.g., “muscle memory” or “middle strength”) are colloquial and would benefit from more formal, technical alternatives.

• Grammar and syntax: While not frequent, there are instances of awkward sentence construction and unnecessarily long sentences that may hinder readability. Streamlining syntax and ensuring subject–verb agreement would further improve clarity.

• Conciseness: Several sections, particularly in the Discussion, could be made more concise by reducing redundancy and avoiding overly conversational phrasing.

Overall, while the language does not impede comprehension, a thorough copy-editing pass by a native English speaker with expertise in biomedical writing would substantially improve the polish and professionalism of the manuscript.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This suty take a nethod called proprioceptive muscle memory to estimate the clamp compression force in the spinal fusion surgery. This method was developed sue to the regulatory limitation (direct force measurements at the implant–bone interface were not feasible?? in line 230) Here are some comments for the authors:

1. This is an interested evaluation of compression force of clamp. How to overcome the interference from the OR evironment, such as the talk noice, distractions, muscle fatigue, and so on?
2. Is it possible to set a objective means to keep the "feeling fresh" between the surgeon hand and the force sensor, and it is reliable, based on a scientific principle? such as a flexible mechanism in the clamp which can be proportional to the clamp force. More quantitative description is necessary to reveal the feasiblity.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you to the authors for the effort invested in revising the manuscript. In its current form, the paper meets all the criteria and can be recommended for publication.

     

Reviewer 2 Report

Comments and Suggestions for Authors

Additional Comments after Revision

The authors have satisfactorily addressed all major and minor comments raised in the previous review round. The revised manuscript shows clear improvement in methodological transparency, data presentation, and overall coherence. The experimental setup and analytical process are now described in sufficient detail, allowing better reproducibility and comprehension. The discussion section has been expanded and now provides stronger linkage between the study findings and the current body of literature. Figures and tables have been refined for clarity, and the overall language quality has been substantially improved, meeting the editorial standards of the journal.

Overall, the authors have made commendable efforts to revise their work thoroughly in response to reviewers’ feedback. The manuscript now demonstrates enhanced scientific rigor, clarity.