Effects of Artificial Achilles Tendon on Hindlimb Movement Biomechanics and Muscle Morphology in Rabbits

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review this manuscript. This study evaluates the biomechanical effects and muscle morphological changes of a PET-SI artificial Achilles tendon in a rabbit model, providing intriguing insights into the potential application of artificial materials for tendon injury treatment. I commend the authors for their effort and offer the following comments to further improve the manuscript:

1. The conclusion states that the artificial Achilles tendon did not demonstrate superiority over the TE group in biomechanical support during hopping. However, the manuscript also presents several favorable outcomes associated with the artificial tendon. Therefore, I recommend revising the conclusion to better reflect a balanced interpretation of both the potential advantages and limitations of the artificial tendon.
2. One major limitation is the lack of evaluation of the mechanical properties of the PET-SI artificial tendon used in the study. Without this information, it is difficult to interpret which specific characteristics of the implant may have contributed to the observed biomechanical or morphological outcomes. While this may be addressed in future work, I suggest the authors discuss how this omission may influence the current findings and interpretation.
3. The manuscript notes a lack of functional pseudosheath formation around the artificial tendon, unlike findings from previous studies involving tibialis anterior tendon reconstruction. While the reason for this discrepancy is stated as "unknown," further discussion of potential factors—such as anatomical location, surrounding tissue structure, and differing mechanical demands—would enhance the depth of the comparison.
4. While the rationale for setting the artificial tendon length approximately 15% shorter than the native tendon is appreciated, more detailed information on how the final implanted system compared to the native functional tendon length is lacking. If the artificial tendon was too long or too short, it could have affected joint range of motion and muscle tension, potentially impacting functional outcomes. Please consider elaborating on this aspect.
5. The study duration of 8 weeks may be relatively short to fully capture tendon healing, neuromuscular adaptation, and functional recovery. While the authors acknowledge this as a limitation, I suggest discussing more concretely how this duration may have influenced the findings.
   Additionally, the small sample size (n = 4–5 per group) may have reduced the statistical power, particularly in outcomes where no significant differences were observed. This limitation should be explicitly considered in the discussion.
6. The study presents plantar pressure data for the operated limb (left hindlimb), but does not provide equivalent data for the contralateral (right) limb or report on the bilateral load distribution. After Achilles tendon surgery, compensatory loading of the contralateral limb is a common adaptive strategy. If possible, presenting data from the unoperated limb and evaluating the temporal and intergroup changes in load distribution ratios would provide a more comprehensive understanding of the biomechanical contribution of the artificial tendon.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript titled “Effects of Artificial Achilles Tendon on Hindlimb Movement Biomechanics and Muscle Morphology in Rabbits” presents a study evaluating the use of a polyester silicone-coated (PET-SI) artificial tendon as a substitute for the Achilles tendon in a rabbit model. The authors employed kinetic, kinematic, and muscle ultrasound assessments to analyze outcomes. Although the subject matter is interesting and pertinent, there are certain issues that must be resolved before the manuscript can be accepted for publication.

Overall, my main suggestion is to provide a better illustration of the surgery procedure sequence and a more detailed description of the ultrasound exam. Additionally, all statements in the Introduction section should be properly supported with citations. Another key point concerns the image showing the markers. It appears that the grids may interfere with the capture of the reflective markers.

I have attached a document with detailed comments organized by section for your reference.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your detailed responses and revisions. I confirm that all six of my comments have been appropriately addressed. The manuscript has been improved in clarity and scientific rigor. I have no further concerns and support its progression in the review process.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for submitting the revised manuscript. I appreciate that most of my previous comments have been addressed. Although the surgical procedure plate was not provided, Figure 2 is now of better quality, which improves the understanding of the methodology.