2026/06/04 by Se‐Han Jung, Hong Seon Lee, Min Jung +6
Medicine · #Mesenchymal stem cell research #Osteoarthritis Treatment and Mechanisms #Total Knee Arthroplasty Outcomes
paper · doi:10.1002/arj.70333
openalex publication_date 2026/06/04 · openalex created_date 2026/06/06 · openalex updated_date 2026/07/30
We sincerely thank Dr. Zhang and colleagues for their interest in and thoughtful comments1 on our article, “Anterior-to-Central Cartilage Defects of Arthritic Knees Showed Better Cartilage Regeneration Than Posterior Cartilage Defects Using Mesenchymal Stem Cell Implantation,”2 particularly for highlighting the importance of containment in the outcomes of cell-based cartilage repair. Cartilage defect size has consistently been reported in several studies as a significant prognostic factor in cell-based cartilage repair.3, 4 Likewise, containment is considered critical, as it affects the loading forces applied to the repaired cartilage.5 Larger defect sizes are often accompanied by containment issue. As the reader noted, it is difficult to determine whether defect size or containment is the predominant factor influencing outcomes. However, the criteria for assessing containment are not always straightforward and are often difficult to define. For this reason, despite its potential major influence on cartilage repair, containment has been relatively underevaluated in the current literature. The references cited by Dr. Zhang and colleagues in their letter1 appear to be mainly review articles, mostly on broader or different topics, rather than original studies directly validating containment as a prognostic factor in cartilage repair.6-8 The specific reference cited for the “validated containment criterion” is also a review paper, making it difficult to confirm its direct relevance.8, 9 Setting aside the relevance of the references, the classification of contained and noncontained lesions in our study is largely consistent with the principle mentioned in the letter. Specifically, we categorized a lesion as contained if the rim cartilage was intact at grade 2 or higher (≥50% of cartilage thickness preserved). The main difference is that our definition was not limited to the posterior rim; instead, if any part of the peripheral margin (anterior, medial, or lateral) failed to meet this criterion, the lesion was classified as noncontained. Based on this definition, 75% of lesions in group P were noncontained, but this does not necessarily imply posterior rim compromise. In fact, in our cohort, thinning of the medial rim cartilage was observed more frequently than loss of posterior rim thickness, whether assessed on magnetic resonance imaging or arthroscopically. This finding is not limited to defects with posterior extension. Also, in general, defect preparation is performed to create a thick vertical wall along the rim as much as possible; therefore, there appears to be no particular reason for containment to be more compromised in the posterior region. We fully agree with Dr. Zhang and colleagues that containment or peripheral rim support plays a major role in cartilage regeneration. Future research should therefore employ standardized and clearly defined criteria in well-designed study specifically focused on cartilage defect containment. We appreciate the valuable insights provided in this letter, which will help refine future investigations in this field. The authors (S-H.J., H.S.L., M.J., K.C., S.K., J.C., C-H.C., S-H.K.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.