Letter to the Editor regarding “arthroscopy combined with high tibial osteotomy promotes cartilage regeneration in osteoarthritis”

To the Editor,

Recently, we read with the article by Wu et al. ¹ We acknowledge and thank the authors for their study. They concluded that arthroscopy combined with high tibial osteotomy (HTO) may improve cartilage regeneration in knee osteoarthritis through P-ERK1/2 by retrospectively analyzing cartilage regeneration in 50 patients after arthroscopic combined HTO. In this study, 1 year after arthroscopy combined with HTO, patients with knee inversion and medial compartment osteoarthritis were seen microscopically with significant new cartilage covering the defect area. Experimental analysis revealed increased protein levels of p-ERK1/2, which may be a potential pathway mechanism affecting cartilage regeneration.

It is worth recognizing the powerful effect of arthroscopy combined with HTO in the treatment of knee osteoarthritis. Another study found that arthroscopy combined with HTO for knee osteoarthritis was effective in reducing the length of hospital stay and postoperative pain in patients. ² And, regarding the mechanism of arthroscopy combined with HTO to promote cartilage regeneration, Otsuki et al. ³ analyzed retrospectively patients after HTO by classifying them into two groups of patients according to clinical and imaging manifestations with or without cartilage regeneration, and there was a significant difference between them in terms of postoperative weightbearing line ratio (WBLR), and maintaining WBLR at 62% after HTO was more favorable for cartilage regeneration and improved clinical manifestations. This suggests to us that the relationship between mechanical mechanisms and cartilage regeneration is also a direction for research.

Meanwhile, in this article, the authors tried to explore the biological mechanism of arthroscopic combined with HTO for cartilage regeneration, and there is still room for further improvement of the overall design. As the authors state, the sample size of the study was too small and only six samples were subjected to protein blotting and polymerase chain reaction. The choice of control group is also questionable. The control cartilage was selected from normal cartilage tissue shed by fracture patients, but the appropriate information about the patients such as age, weight and presence of osteoarthritis was lacking in the description. In addition, is it more appropriate to select preoperative autologous cartilage tissue as a control group due to individual variability, among other reasons. In order to assess cartilage regeneration in postoperative patients, non-pumping examinations such as imaging could be added as a means of assessment, and whether it is ethical to obtain newly generated cartilage tissue directly from patients after surgery remains to be further discussed. Interestingly, the authors' study suggests a potential pro-chondral regeneration pathway, but this is only at the initial stage. In order to elucidate the relationship between arthroscopic combination of HTO for cartilage regeneration and ERK1/2 signaling pathway, a better study protocol is needed to dissect it from positive and negative directions. We again thank the authors for dissecting the cartilage regeneration in patients with arthroscopic combination of HTO, and this work will benefit the treatment of osteoarthritis.