C5 Palsy after Cervical Disc Arthroplasty: Two Case Reports and Literature Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study is a report of C5 palsy after cervical arthroplasty and has very useful clinical information. I have several comments on this report.
1. Please change the title to "Two case reports and literature review".

2. The abstract is too short to understand the essence of the case. Please provide a summary of the case and the topic sentence of this report.

3. Figure 3 mentions foraminal stenosis. Please add Axial view of C4-5.

4. Please add Axial view of C3-4 and 4-5 to Figure 1.

5. Srikantha, Umesh; Hari, Akshay; Lokanath, Yadhu K; Somasundar, Deepak; Rao, Shilpa1. Delayed C5 palsy following anterior cervical discectomy and arthroplasty – Rare presentation of two cases by an unusual phenomenon of “flosealoma”. Journal of Spinal Surgery 9(2):p 128-133, Apr–Jun 2022. | DOI: 10.4103/joss.joss_3_22

I suggest that you include this study in Discussion.

Author Response

Reviewer 1 Comments

This study is a report of C5 palsy after cervical arthroplasty and has very useful clinical information. I have several comments on this report.

Response: Thank you for reviewing our study and providing useful recommendations to better enhance the quality of our case report. We appreciate your help.

Comment 1. Please change the title to "Two case reports and literature review".

Response 1: Title was changed to Two case reports and literature review. Thanks for the recommendation.

Comment 2. The abstract is too short to understand the essence of the case. Please provide a summary of the case and the topic sentence of this report.

Response 2: Thanks for the observation, the Abstract was revised and expanded for more detail and direction. The abstract was expanded from line 10-15.

Cervical Disc Arthroplasty (CDA) has become an alternative for the treatment of cervical spondylosis with radicular or myelopathic symptoms, however there is limited literature regarding its complications and outcomes. We present two cases that develop C5 nerve palsy (C5P) following CDA. Both cases presented with C5P in a delayed fashion and symptoms improved with conservative management. These separate cases serve as one of the first cases reported in the literature that present with delayed C5P after cervical arthroplasty and resolve with conservative treatment. These cases can potentially guide spine surgeons to treat similar patients in the future and improve outcomes.  

Comment 3.  Figure 3 mentions foraminal stenosis. Please add Axial view of C4-5.

Response 3: Thank you for the observation, The Axial view of the C4-C5 disc space level was added in Figure 3 in the (right column).

Comment 4. Please add Axial view of C3-4 and 4-5 to Figure 1.

Response 4: Thank you for your observations. The C4-C5 axial view was added in the images of Figure 1. The Text was edited removing “stenosis C3-C4” due to the fact that it was mild, and the amount of stenosis was not significant at C3-C4 and thus, it was not addressed surgically.

Comment 5. 

Srikantha, Umesh; Hari, Akshay; Lokanath, Yadhu K; Somasundar, Deepak; Rao, Shilpa1. Delayed C5 palsy following anterior cervical discectomy and arthroplasty – Rare presentation of two cases by an unusual phenomenon of “flosealoma”. Journal of Spinal Surgery 9(2):p 128-133, Apr–Jun 2022. | DOI: 10.4103/joss.joss_3_22

I suggest that you include this study in Discussion.

 

Response 5: Thanks for your observation, we added this study in our discussion section and compared it to our cases. You can observe the mention in line numbers 167-176 of page 6. Great suggestion.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

 The Authors present two cases of C5 nerve palsy (C5P) following cervical disc arthroplasty (CDA).

The overall incidence of C5P is at 5.3%, according to the study of Shou et al. (referenced by the Authors), which makes the article clinically important. However, more studies on this topic have been published as well.

The article seems to be prepared with the rush taking into account the number of editorial mistakes and flaws as follows:

The abstract is scarce and needs to be enriched with the aspects of methodology and the discussion of symptoms that have been found, as well as the study’s significance presented in the last sentence.

Keyword: ACDF sounds mysterious

Introduction:

1. The phrase in line 17,18 …” Classically, C5P is a delayed, usually temporary, focal paresis of the deltoid and possibly the bicep muscle after cervical spine surgery [4, 5]”... needs clarification and grammar corrections.

2. line 19 …”C5 nerve weakness”… is imprecise

3. line 22 …” there have been no reports of C5P following by cervical  arthroplasty”… should be updated, the Authors should look more carefully in the literature.

e.g. Traynelis, V. C., Fontes, R. B. V., Kasliwal, M. K., Ryu, W. H. A., Tan, L. A., Witiw, C. D., Dettori, J. R., Brodt, E. D., & Skelly, A. C. (2023). Risk factors for C5 palsy: a systematic review and multivariate analysis. Journal of neurosurgery. Spine, 40(2), 216–228. https://doi.org/10.3171/2023.9.SPINE221352

Deshpande, N., Stino, A. M., Smith, B. W., Little, A. A., Yang, L. J. S., Park, P., & Saadeh, Y. S. (2022). Defining postoperative C5 palsy and recovery: a systematic review. Journal of neurosurgery. Spine, 38(4), 457–464. https://doi.org/10.3171/2022.11.SPINE221067

Material and methods.

1. Many grammar errors have been found e.g. line 38,39 …”The patient was discharge…” etc., as well as throughout the text.

2. what do you mean in lines 40, 41… with resolution of pre-operative symptoms”… ….”she was full strength bilaterally at time of discharge”… did you measure clinically the muscle strength with Lovett/MMT scale? Please provide the initial and final score. Sometimes you use “the power” sometimes “strength”.

3. The description of Case 2 is modest, and the way it is described is not comparable to that of Case 1.

4. Please comment carefully on the content of Figures as the Results (Cases presentation).

Discussion:

1. The sentence in lines 105, 106 …”Although C5P is a well noted complication after cervical spine surgery, no reports to date describe C5P after arthroplasty.”… is not true. Please provide more references.

e.g. Lee, S. H., Suk, K. S., Kang, K. C., Cho, S. W., Juh, H. S., Lee, J. H., & Kim, K. T. (2016). Outcomes and Related Factors of C5 Palsy Following Cervical Laminectomy With Instrumented Fusion Compared With Laminoplasty. Spine, 41(10), E574–E579. https://doi.org/10.1097/BRS.0000000000001343

2. Most sentences are not understood well in their meaning.

3. No study limitations are provided.

4. Line 136. The sentence …” we present a novel presentation of a well characterized complication of 

cervical spine surgery.”… is doubtful. 

Conclusions are repetitions of the discussion content.

Line 162. Data Availability Statement: No data was obtained by performing this study. – The sentence is not true.

 

References are not in accordance with MDPI citation fashion.

Comments on the Quality of English Language

Needs major improvements

Author Response

Reviewer 2- Updates are attached as a word document as well. Thanks

General Comments: The Authors present two cases of C5 nerve palsy (C5P) following cervical disc arthroplasty (CDA). The overall incidence of C5P is at 5.3%, according to the study of Shou et al. (referenced by the Authors), which makes the article clinically important. However, more studies on this topic have been published as well. The article seems to be prepared with the rush taking into account the number of editorial mistakes and flaws as follows:

Response:

Thank you for reviewing our study and providing recommendations to further improve the quality of our case reports and review of literature. The observations were truly taken into consideration and thoroughly analysed. The article was prepared more in depth and the editorial mistakes and flaws were corrected.

Comment 1: The abstract is scarce and needs to be enriched with the aspects of methodology and the discussion of symptoms that have been found, as well as the study’s significance presented in the last sentence.

Response 1:  The abstract was enhanced, and a more thorough explanation was provided in the abstract section.

Comment 2: Keyword: ACDF sounds mysterious.

Response 2: The keyword was changed to anterior cervical discectomy.

Introduction:

Comment 3:  The phrase in line 17,18 …” Classically, C5P is a delayed, usually temporary, focal paresis of the deltoid and possibly the bicep muscle after cervical spine surgery [4, 5]”... needs clarification and grammar corrections.

Response 3: The sentence was corrected and summarized for better clarification. C5P presents as new unilateral weakness of the deltoid and biceps muscles immediately or several days after surgery.  Now present in lines 21-23.

Comment 4: line 19 …”C5 nerve weakness”… is imprecise

Response 4: Thank you for noticing the error. The correct medical term was placed, shown below.

The diagnosis of C5P is one of exclusion, usually temporary and other etiologies for shoulder abduction weakness must be ruled out, including disc herniation, residual stenosis, or hematoma. (line 25).

Comment 5: there have been no reports of C5P following by cervical  arthroplasty”… should be updated, the Authors should look more carefully in the literature.

e.g. Traynelis, V. C., Fontes, R. B. V., Kasliwal, M. K., Ryu, W. H. A., Tan, L. A., Witiw, C. D., Dettori, J. R., Brodt, E. D., & Skelly, A. C. (2023). Risk factors for C5 palsy: a systematic review and multivariate analysis. Journal of neurosurgery. Spine, 40(2), 216–228. https://doi.org/10.3171/2023.9.SPINE221352

Deshpande, N., Stino, A. M., Smith, B. W., Little, A. A., Yang, L. J. S., Park, P., & Saadeh, Y. S. (2022). Defining postoperative C5 palsy and recovery: a systematic review. Journal of neurosurgery. Spine, 38(4), 457–464. https://doi.org/10.3171/2022.11.SPINE221067

Response 5: Thank you for providing additional studies to add to our literature review. These were added in the manuscript and used to describe MMT. I believe that most studies focused on posterior laminectomy, acdf and anterior corpectomies but not on cervical arthroplasty or cervical disc replacement cases were labelled in the studies mentioned.

Material and methods.

Comments 1:  Many grammar errors have been found e.g. line 38,39 …”The patient was discharge…” etc., as well as throughout the text.

Response 1: Thank you for noticing these grammatical errors. They were corrected and revised multiple times. The patient was discharged home on post-operative day 1 with resolution of pre-operative symptoms; she was full strength bilaterally at time of being discharged from the hospital.

Comments 2: what do you mean in lines 40, 41… with resolution of pre-operative symptoms”… ….”she was full strength bilaterally at time of discharge”… did you measure clinically the muscle strength with Lovett/MMT scale? Please provide the initial and final score. Sometimes you use “the power” sometimes “strength”.

Response 2: The physical exam was explained in detail using the MMT scales. Thank you for providing clarification regarding this.

On her MMT scale she was (5/5) in all muscle groups.  Line 47

Neuromonitoring remained stable throughout the procedure. The patient was discharged home on post-operative day 1 with resolution of her bilateral upper extremity pain; she was (5/5) on MMT on all muscle groups. Line 45-47

Comments 3: The description of Case 2 is modest, and the way it is described is not comparable to that of Case 1.

Response 3: Case 2 was described more thoroughly and more in depth, like Case 1. Changes in wording and structure were corrected.

4. Please comment carefully on the content of Figures as the Results (Cases presentation).

Response 4: Comments were corrected carefully in the Figure section and Case presentations.

 

 

Discussion

Comment 1: The sentence in lines 105, 106 …”Although C5P is a well noted complication after cervical spine surgery, no reports to date describe C5P after arthroplasty.”… is not true. Please provide more references.

e.g. Lee, S. H., Suk, K. S., Kang, K. C., Cho, S. W., Juh, H. S., Lee, J. H., & Kim, K. T. (2016). Outcomes and Related Factors of C5 Palsy Following Cervical Laminectomy With Instrumented Fusion Compared With Laminoplasty. Spine, 41(10), E574–E579. https://doi.org/10.1097/BRS.0000000000001343

 

Response 1: Thank you for your observation. However, the study mentioned above refers to laminoplasty which is a posterior cervical approach which is very common to cause C5 Palsy and has been published previously. We report cases of cervical arthroplasty which is an anterior approach to the cervical spine for disc replacement surgery. The study cited above does not mention any cervical arthroplasty cases just compares cervical laminectomy vs laminoplasty on C5 palsy patients. This observation made us realize that the cervical arthroplasty needs to be explained in a clearer manner.

Comment 2:  Most sentences are not understood well in their meaning.

Response 2: The Discussion was revised and organized in a clearer way to improve the meaning of the sentences.

Comments 3: No study limitations are provided.

Response 3: Thank you for noticing that this section was missing from our manuscript, great observation. Limitations were added in the discussion section in lines 169-173.

Our study has some limitations despite of presenting only two cases. CDA is a rare surgical procedure and is only indicated in some patients with cervical spine pathology. Also, C5P is rare after anterior cervical spine surgery thus, the number of cases reported in the literature are limited. It is imperative to further obtain more cases to establish a cause and prevention of C5P.

Comments 4:  Line 136. The sentence …” we present a novel presentation of a well characterized complication of cervical spine surgery.”… is doubtful. Conclusions are repetitions of the discussion content.

Response 4: The conclusions were edited and improved to avoid repetition.

Comment 5: Line 162. Data Availability Statement: No data was obtained by performing this study. – The sentence is not true.

Response 5: Data availability statement was changed accordingly and appropriately.

Data Availability Statement: The data for this study was obtained by using the EMR to obtain the cases information. To protect the patients identities, this information is reserved. 

Comment 6: References are not in accordance with MDPI citation fashion.

Response 6: References were changed to match the MDPI citation.

 

 

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

·  Main Question Addressed by the Research: The research investigates the occurrence of C5 palsy (C5P) after cervical disc arthroplasty (CDA). It aims to present two cases of C5P following CDA and discusses these cases within the context of existing literature on C5P after cervical spine surgery.

 

·  Original or Relevant Parts for the Field and Specific Gap Addressed: The originality lies in the presentation of C5P cases specifically after CDA, a complication previously undocumented for this procedure. The research addresses the gap in literature concerning the complications and outcomes of CDA, particularly focusing on the development of C5P, which is well-documented in other types of cervical spine surgeries but not in CDA.

 

·  Contribution to the Subject Area Compared to Other Published Material: This study adds novel case reports of C5P following CDA, expanding the understanding of complications related to this relatively new surgical technique. It situates the occurrence of C5P within the broader spectrum of cervical spine surgeries, providing insights into its incidence and management in the context of CDA.

 

·  Improvements in Methodology and Further Controls:

 

·  Methodology Improvements: The authors should consider a larger sample size for more comprehensive data on the incidence and predictors of C5P after CDA.

 

· Further Controls: Inclusion of a control group of patients undergoing other types of cervical spine surgeries would help compare the incidence and recovery patterns of C5P. Additional controls for patient comorbidities and surgical techniques could refine the findings.

 

·  Consistency of Conclusions with Evidence and Arguments Presented: The conclusions align with the evidence and arguments presented, demonstrating that C5P can occur after CDA and that it can be managed effectively with conservative treatment.

 

·  Appropriateness of References: The references are appropriate, citing relevant studies on C5P after various types of cervical spine surgeries. Key studies are included to support the discussion on the etiology, incidence, and management of C5P.

 

·  Additional Comments on Tables, Figures, and Quality of Data:

 

·  Figures: The figures are well-chosen and effectively illustrate the clinical findings, surgical interventions, and postoperative outcomes. They complement the text and provide visual support for the cases discussed.

 

Author Response

Review 3- Recommendations attached and included in the manuscript.

Thanks

 

Main Question Addressed by the Research: The research investigates the occurrence of C5 palsy (C5P) after cervical disc arthroplasty (CDA). It aims to present two cases of C5P following CDA and discusses these cases within the context of existing literature on C5P after cervical spine surgery.

 Comment 1: Original or Relevant Parts for the Field and Specific Gap Addressed: The originality lies in the presentation of C5P cases specifically after CDA, a complication previously undocumented for this procedure. The research addresses the gap in literature concerning the complications and outcomes of CDA, particularly focusing on the development of C5P, which is well-documented in other types of cervical spine surgeries but not in CDA.

Response 1: Thank you for the feedback and positive comments. We appreciate the effort in improving our manuscript.

 Comment 2: Contribution to the Subject Area Compared to Other Published Material: This study adds novel case reports of C5P following CDA, expanding the understanding of complications related to this relatively new surgical technique. It situates the occurrence of C5P within the broader spectrum of cervical spine surgeries, providing insights into its incidence and management in the context of CDA.

Response 2: Thank you with your comments and agree with your opinion.

Comment 3:  Methodology Improvements: The authors should consider a larger sample size for more comprehensive data on the incidence and predictors of C5P after CDA.

Response 3: Thank you with your comments and agree with your opinion. Unfortunately, these are the only two cases that our institution has ever witnessed, and other cases have not been reported in the literature at this time. We placed in our limitations that our sample size is limited.

 Comment 4:  Further Controls: Inclusion of a control group of patients undergoing other types of cervical spine surgeries would help compare the incidence and recovery patterns of C5P. Additional controls for patient comorbidities and surgical techniques could refine the findings.

Response 4: Thank you with your comments and agree with your opinion. This is a great observation. We will perform a wider study and compare the incidence of C5P in all our cervical spine surgical approaches, though this will change the structure of this case report and it will become a larger study. We are currently working on this study.

Comment 5:  Consistency of Conclusions with Evidence and Arguments Presented: The conclusions align with the evidence and arguments presented, demonstrating that C5P can occur after CDA and that it can be managed effectively with conservative treatment.

Response 5: Thank you with your comments and agree with your opinion.

Comment 6:  Appropriateness of References: The references are appropriate, citing relevant studies on C5P after various types of cervical spine surgeries. Key studies are included to support the discussion on the etiology, incidence, and management of C5P.

Response 6: Thank you with your comments and agree with your opinion.

 

 

Comment 7:  Additional Comments on Tables, Figures, and Quality of Data: Figures: The figures are well-chosen and effectively illustrate the clinical findings, surgical interventions, and postoperative outcomes. They complement the text and provide visual support for the cases discussed.

Response 7: Thank you with your comments and agree with your opinion.

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The author has responded appropriately to my comments and I consider this manuscript acceptable.

Author Response

Thank you for your response. Appreciate your help 

Reviewer 2 Report

Comments and Suggestions for Authors

The Authors have addressed to most of my queries well.

 

Nevertheless, please upgrade the description of the methodology in the Abstract, you have performed the review of the literature as well. Describe the results of the clinical test in the Abstract.

Comments on the Quality of English Language

Minor corrections are required

Author Response

Comment 1: The Authors have addressed to most of my queries well. Nevertheless, please upgrade the description of the methodology in the Abstract, you have performed the review of the literature as well. Describe the results of the clinical test in the Abstract.

Response 1: Thank you for your observation, we have updated the abstract with your recommendations.We gave the description of the methodology in the abstract with description of the physical exam and added that a review of literature was performed. We also described the results of the clinical test at presentation and at the resolved state. Abstract is shown below.

Abstract: Cervical Disc Arthroplasty (CDA), also known as cervical artificial disc replacement, has become an alternative for the treatment of cervical spondylosis with radicular or myelopathic symptoms. However, there is limited literature regarding its complications and outcomes. We present two cases that develop C5 nerve palsy (C5P) following two level CDA. Both patients presented with C5P in a delayed fashion with 2/5 and 1/5 deltoid weakness on MMT, respectively. Post operative imaging did not demonstrate any spinal cord compression and symptoms resolved (5/5 on MMT) with conservative management in both cases. To our knowledge, these represent the first cases of delayed C5P after cervical arthroplasty reported in the literature. We performed a literature review to further enhance our knowledge regarding CDA. By understanding its pathophysiology and response to treatment, these cases can serve as a guide for spine surgeons and improve their future outcomes.