Letter to the Editor: Is Endoscopic Surgery a Safe and Effective Treatment for Lumbar Disc Herniation? A Meta-Analysis of Randomized Controlled Trials

Response to letter to the editor:

1. Thank you for your valuable feedback. Regarding the issue of the literature search cutoff date, as you correctly pointed out, the cutoff date for the literature search mentioned in the Methods section is December 25, 2023. Since we had already completed the literature search when writing the paper, no additional searches were conducted at the time of submission. We submitted the completed manuscript to Global Spine Journal on January 25, 2024, and it was accepted on November 4, 2024. We have ensured that the literature search covered all relevant studies and adhered to best practices for systematic reviews.

2. Regarding your concern about the inclusion of 4 zero-effect studies, we understand your concern. In fact, we included these zero-effect studies in the meta-analysis mainly to illustrate that these studies reported the complication rates as an outcome measure. When performing the data analysis using RevMan software, the software effectively handled the results of these studies, ensuring that they did not significantly impact the overall effect estimate or confidence intervals. We believe that their inclusion in the RevMan statistical model does not introduce bias or affect the reliability of the analysis. The following 2 images show the results of the meta-analysis with and without the inclusion of zero-effect studies, both of which are consistent (Figures 1 and 2).

3. Regarding the registration number issue you mentioned, it was indeed an oversight on our part. The correct registration number should be INPLASY 202410095, not INPLASY2022410095. The relevant website is: https://inplasy.com/inplasy-2024-1-0095/

Figure 1.

Results of the meta-analysis including zero-effect studies. ED: Endoscopic discectomy; NED: Non-endoscopic discectomy.

Figure 2.

Results of the meta-analysis excluding zero-effect studies. ED: Endoscopic discectomy; NED: Non-endoscopic discectomy.

Finally, thank you once again for your attention and support for our article.