Letter to Editor Regarding Article “Knee Osteoarthritis: Clinical and MRI Outcomes After Multiple Intra-Articular Injections With Expanded Autologous Adipose-Derived Stromal Cells or Platelet-Rich Plasma”

Dear Editor,

Recently, we carefully read an article titled “Knee Osteoarthritis: Clinical and MRI Outcomes After Multiple Intra-Articular Injections With Expanded Autologous Adipose-Derived Stromal Cells or Platelet-Rich Plasma” published by Khoury et al. ¹ and fully agree with the authors’ conclusions. The authors compared the clinical manifestations and magnetic resonance imaging (MRI) findings of patients with knee osteoarthritis who received multiple adipose-derived stromal cells (ASCs) or platelet-rich plasma (PRP), and retrospectively analyzed the prognosis of the patients. The authors found that patients receiving intra-articular injections of ASCs had better clinical and radiographic findings than those receiving intra-articular PRP during long-term follow-up. We strongly agree with the research done by the authors, but there are still some areas for improvement in this article.

First, different PRPs will have different effects on the experimental results. Bennel et al. ² found that PRP preparations are characterized by heterogeneity and lack a unified standard. Therefore, the results of this study may need to be more generalizable to other studies on PRP preparations. Second, this study lacked a placebo control group. However, some studies have found that choosing PRP as the control group has a better effect than normal saline, corticosteroids, and hyaluronic acid. ³ Therefore, intra-articular injection of PRP may be a new control strategy for patients with knee osteoarthritis.

In this article, the author wanted to compare the therapeutic effects of injecting different drugs into the joint cavity to treat knee osteoarthritis, but there are still some deficiencies overall. Xu et al. ⁴ conducted a retrospective analysis on the prognosis of knee osteoarthritis patients with intra-articular injection of different drugs and found that in the actual operation process, it cannot be ensured that the same doctor completes the operation of each case. Therefore, the authors should consider the effect of this factor on the experimental results. Second, to evaluate patients’ cartilage regeneration, in addition to imaging methods such as MRI, arthroscopy should also be used as a further evaluation method. ⁵ Finally, we would like to thank the authors again for their study on intra-articular injection of ASCs or PRP for the treatment of knee osteoarthritis. This work is of great help in the treatment of osteoarthritis.