Accuracy of Accelerometer-Based Navigation System Perseus for the Tibial Cut in Total Knee Arthroplasty: No Superiority Compared to Mechanical Instrumentation in Current Practice

Round 1

Reviewer 1 Report

The work "Accuracy of accelerometer-based navigation system Perseus for 2 the tibial cut in total knee arthroplasty: no superiority com- 3 pared to mechanical instrumentation in current practice" is novel in terms of work and technique. 

The study is well organized and well presented. However the presentation of results should be elaborate and the conclusions should also be more vividly decscribed. 

Author Response

 

Dear Editors,

Thank you a lot for your relevant comments, there are comments about revision we did.

(Reviewer 1)

 

About similarity index:

-Section 1 (red): modifications done

Line 37-44:

Nevertheless, despite the type of alignment (mechanical, kinematic, restricted kinematic), the accuracy of the tibial and femoral cuts remains important.

This is especially important for kinematic alignment, because an error of 3° in the component alignment has serious consequences when the targeted alignment is already in varus or valgus.

That is why these tools are useful particularly during surgeries with individualized component alignment.

In a previous study, the recommended alignment in the coronal plane (within 3° of a neutral mechanical axis) was achieved in only 70-80% of patients undergoing conventional TKA using extra and intramedullary guides.

However, regardless of the type of alignment (mechanical, kinematic, limited kinematic), the accuracy of the tibia and femur cuts is still crucial.
This is especially important for kinematic alignment. A 3° error in component alignment has serious consequences if the target alignment is already in varus or valgus.

A previous study has showed that TKA performed with extramedullary guides have a correct coronal aligment (more or less 3° around neutral mechanical axis) in only 70 to 80% of cases [3]. 

 

 Line 210-215 :

Budhiparama et al. has described the results of the main studies about accelerometers in a systematic review [12]. Five of nine studies favored accelerometer-based navigation for the restoration of HKA [13, 14, 25, 30, 31], while four of nine studies found no differences between the study groups [18, 26, 32, 33]. In terms of coronal-axis alignment of the femoral component, seven of nine studies favored accelerometer-based navigation [13, 14, 18, 25, 30, 31]. There was no significant difference in sagittal alignment.

 

Budhiparama et al. has described the results of the main studies about accelerometers in a systematic review [12]. Five of nine studies found a better HKA restoration in accelerometer-assisted TKA [13, 14, 25, 30, 31], while the other four found no difference between the two procedures (conventional vs accelerometers) [18, 26, 32, 33]. Regarding femoral component coronal-axis alignment, seven of nine studies found a better precision with accelerometer-based navigation [13, 14, 18, 25, 30, 31]. [13, 14, 18, 25, 30, 31]. Nevertheless, there was no significant difference in sagittal alignment.

 

-Section 2 (pink): no modifications because it is some details about post-operative protocol for total knee arthroplasty in our department, so there are few similarities with literature because of the papers we have already published.

-Section 3 (purple): modifications done

Line 51-58:

Accelerometer-based navigation is a handheld, sterile device used within the operative field to determine the hip center of rotation and the femoral mechanical axis, which are used to determine the resection planes of the distal femur and the proximal tibia [5]. These systems are wireless and imageless, and they capture data during the procedure, and directly display the data on pods, which are attached to the femoral and tibial resection guides within the surgical field. These systems guide resection angles in the coronal and sagittal planes and confirm alignment accuracy of the femoral and tibial components after resection

Accelerometer-based navigation is a handheld, sterile device used within the operative field to determine the resection planes of distal femoral and proximal tibial cut analyzing hip rotation center and femoral mechanical axis. These wireless, imageless systems collect data intraoperatively and display the data directly on pods attached to the femoral and tibial resection guides

These systems guide resection angles in the coronal and sagittal planes, and also can confirm alignment accuracy of cuts after resection.

 

-other sections: no modifications, seems to be not significant similarities

 

Others comments:

-results section:  Figure 3 added to elaborate presentation of results

 

 

-Conclusion had been extended and detailed:

Line 236-241

This accelerometer-based navigation system during TKA didn’t improve the accuracy of the tibial cut compared to the conventional technique, but it restored the tibial slope.

This accelerometer-based navigation system during TKA did not improve the accuracy of the tibial cut in the coronal plane compared to the conventional technique, but it did restore the tibial slope, and led to a low and comparable rate of radiological outliers.  However, by having an accuracy not inferior to the conventional technique, this system can be a real asset for the surgeon and the patient in case of failure of the standard instrumentation without significant additional cost and with a satisfactory accuracy. 

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

• The use of the device and the "software and sensors" in Figure 1 can be shown schematically as "Scheme 1".

• Attention should be paid to superscripts: For example: kg/m2.

• All abbreviations in Table-1 should be explained. For example: y.o

• “5. The “Conclusions” section should be expanded.

• “Future Perspective” section can be added

• References should be updated by citing studies that belong to the years 2022 and 2023.

 

• Original sentences and explanations should be used instead of the sentences in the study "https://doi.org/10.3390/jcm10010047".

Author Response

 

Dear Editors,

Thank you a lot for your relevant comments, there are comments about revision we did.

(Reviewer 2)

• The use of the device and the "software and sensors" in Figure 1 can be shown schematically as "Scheme 1".

-> Not sure to understand the significance of modification asked for, very sorry.

• Attention should be paid to superscripts: For example: kg/m2.

-> Modification done in table 1

• All abbreviations in Table-1 should be explained. For example: y.o

-> Modification done in table 1

 

• “5. The “Conclusions” section should be expanded.

-> Modification done

New conclusion: This accelerometer-based navigation system during TKA didn’t improve the accuracy of the tibial cut in the coronal plane compared to the conventional technique, but it did restore the tibial slope, and led to a low and comparable rate of radiological outliers. However, by having an accuracy not inferior to the conventional technique, this system can be a real asset for the surgeon and the patient in case of failure of the standard instrumentation without significant additional cost and with a satisfactory accuracy.

 

• “Future Perspective” section can be added

-> Section added at the end of Discussion:

A larger-scale, prospective, randomized trial would improve knowledge of the effect of this technology on long-term results, both in terms of quality of life, functional results and implant survival (long-term loosening rate). In addition, accelerometer assistance would allow navigation for the distal femoral cut as well, and the study of the combined precision of the tibial and distal femoral cuts would be relevant. On another side, the evolution towards reusable sensors would be preferable to single-use sensors, however the sterilization of electronic equipment is still difficult to achieve.

• References should be updated by citing studies that belong to the years 2022 and 2023.

-> Modification done, we added those references:

- Accelerometer-based navigation vs. conventional techniques for total knee arthroplasty (TKA): a systematic review and meta-analysis of randomized controlled trials

Juntan Li ^# 1, Yuqi Zhang ^# 2, Xiang Gao ³, Tianxu Dou ¹, Xu Li ⁴

Arthroplasty. 2022 Sep 2;4(1):35.doi: 10.1186/s42836-022-00135-6.

L 212-214: In addition, Li et al. in a recent systematic review of randomized controlled trials, found less outliers for mechanical alignment (relative risk increase of 38% to have outlier with conventional technique)

- Comparative Analysis of Radiological Evaluation and Early Functional Outcomes of Total Knee Arthroplasty Using an Accelerometer-Based Handheld Navigation System and Conventional Instrumentation: A Prospective Study

Nuthan Jagadeesh ¹, Hiranya Kumar ¹, Varma Sarparaju ¹, Vishwanath Shivalingappa ¹

Cureus. 2022 Jan 9;14(1):e21039. doi: 10.7759/cureus.21039. eCollection 2022 Jan

L222-226, added paragraph:  More recently, Jagadeesh et al., in a prospective study about 122 TKA, found a good accuracy of accelerometer navigation system for tibial cut, finding a better precision on TMA and HKA angles (89.2 ± 1.7° and 179.2 ± 1.8° in accelerometer-navigation group, and 87.4 ± 1.5° and 177.3 ± 2.8° in conventional technique group)

 

• Original sentences and explanations should be used instead of the sentences in the study "https://doi.org/10.3390/jcm10010047".

-> Modifications done do decrease similarity index for those sentences

 

Reviewer 3 Report

Thank you for the opportunity to review this paper.

It is an interesting and current theme in the area of intervention in question.  I have some observations to make and suggestions to improve the paper.

Abstract

You should consider changing the keywords so they are not repeated with the title of the article.

Introduction

To clarify better the advantages of using this technique/method.

Uniformize the objective of the abstract with the objective of the introduction.

Materials and Methods

In table 1 it is missing to legend the remaining acronyms or symbols

Results

In table 2 it is missing to legend the remaining acronyms or symbols

Discussion

In the discussion it would be pertinent to make a more specific reference regarding the rehabilitation of these patients, what are the advantages for an early rehabilitation, what implications it may have in the beginning of the patient's rehabilitation.

Author Response

 

Dear Editors,

Thank you a lot for your relevant comments, there are comments about revision we did.

(Reviewer 3)

Abstract

You should consider changing the keywords so they are not repeated with the title of the article.

->Modification done

Total knee arthroplasty; accelerometer-based navigation; tibial cut; component alignment

Knee arthroplasty, navigation system, accelerometer-based navigation, component alignment, radiological evaluation of total knee arthroplasty

Introduction

To clarify better the advantages of using this technique/method.

Uniformize the objective of the abstract with the objective of the introduction.

-> Modification done

Sentence: ‘’ The objective of this study was to determine the accuracy of the Perseus System for making the tibial cut on TKA’’ has been add to the abstract to clarify the mean objective before explanation of primary and secondary endpoints

Materials and Methods

In table 1 it is missing to legend the remaining acronyms or symbols

-> Modification done

Results

In table 2 it is missing to legend the remaining acronyms or symbols

-> Modification done

 

Discussion

In the discussion it would be pertinent to make a more specific reference regarding the rehabilitation of these patients, what are the advantages for an early rehabilitation, what implications it may have in the beginning of the patient's rehabilitation.

-> Thank you for your relevant comment. This was a point discussed during the drafting process. The comparison of clinical results between the two groups was deliberately not made, as the objective of alignment was the same between the two groups, with differences on radiological measurements of the order of a few degrees. It does not seem clinically relevant to compare the early clinical results of patients with only 1 to 3° difference on X-ray. Navigation, in this study with a mechanical alignment objective, is not intended to improve postoperative follow-up. Analysis of the clinical results and survival of the implant would be interesting in the long term depending on the alignment, but the literature is already very rich on the subject and this was not the objective of the study.

 

 

 

Author Response File: Author Response.docx