Comment on Paolo et al. “Effect of pulsed electromagnetic field therapy in patients undergoing total knee arthroplasty: a randomized controlled trial”

Dear Editor,

We read Paolo et al.’s article “Effect of pulsed electromagnetic field therapy in patients undergoing total knee arthroplasty: a randomized controlled trial” [1] with interest and would like to congratulate the authors on this interesting study. Nevertheless, we have several queries that we would like to communicate to the authors.

1. Data regarding the 26 patients (12 in the treated group, 14 in the control group) which were available for final analyses, that sample size is too small. In order to improve the reliability of the results, we propose statistically evaluating the data.

2. Data on 26 patients were available for final analyses, whereas pre-operative evaluation involved 58 consecutive patients with an indication for total knee arthroplasty (TKA), of whom only 33 (18 male, 15 female) matched the inclusion criteria. Why, then, does the final data involve 26 patients only?

3. In this study, patients undergoing different types of surgery were included; we suggest comparing patients undergoing the same type of surgery between different groups. We also recommend performing a subgroup analysis for sex in each group, which could improve the reliability of the results.

4. The results of multicentre controlled clinical studies are more scientific and persuasive than the results of this study, and they can help reduce the difference between participants’ geographical area and ethnicity.

We agree with the authors’ conclusions: the main limitation of this study is the lack of a double-blind condition, as a placebo group was not included. However, physicians who performed patient evaluations were blinded to the assigned group, and thus objective evaluations in this study are reliable