Shocking Results of Platelet-Rich Plasma Administration Concurrent With Autologous Chondrocyte Implantation - Response

Sep 28, 2026

This response addresses questions about the authors’ article on the effect of platelet-rich plasma (PRP) on autologous chondrocyte implantation (ACI) for chondral defects using an in vivo rabbit model. It explains why PRP-negative effects on ACI outcomes were interpreted within the study’s goal of maximizing ACI efficacy, outlines methods used to ensure reproducibility, and discusses sutures, defect geometry, PRP volume retention, and timing of PRP delivery. Delayed administration at 2 weeks is reported to improve repair outcomes.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Impact of Platelet-Rich Plasma’s Negative Effects on ACI

Techniques and Consistency With Previous Studies

Responses to Specific Comments

Foreign Body and Thickness Effects of Nylon Sutures

Impact of Defect Diameter and Depth

Potential PRP Loss and Volume Consideration

Timing of PRP Administration

Conclusion

Response Shocking Results of PlateletRich Plasma Administration Concurrent With Autologous Chondrocyte Implantation Negatively Impacting Cartilage Repair: Response We appreciate the thoughtful feedback and questions raised regarding our article titled ‘‘Effect of Platelet-Rich Plasma on Autologous Chondrocyte Implantation for Chondral Defects: Results Using an In Vivo Rabbit Model.’’5 The insights provided have stimulated a valuable discussion and allowed us to reflect further on our methodology and findings. Below, we address the key points raised by the authors of the letter to the editor. Impact of Platelet-Rich Plasma’s (PRP’s) Negative Effects on Autologous Chondrocyte Implantation (ACI) The finding that PRP may exert negative effects on ACI outcomes has had a profound impact on our understanding of its role in cartilage repair. This result aligns with the growing body of evidence suggesting that PRP’s primary clinical benefit lies in its anti-inflammatory properties rather than direct cartilage regeneration.1 However, we emphasize that the primary objective of our study was to investigate whether PRP could enhance cartilage repair following ACI (ie, to maximize the therapeutic efficacy of current ACI treatment) . We focused on cartilage regeneration as the primary outcome measure. Techniques and Consistency With Previous Studies Regarding the use of nonabsorbable nylon sutures for collagen membrane fixation and the creation of cartilage defects, we adopted protocols consistently utilized in our extensive series of experiments involving the development of 3-dimensional autologous cultured cartilage sheets (JACC; Japan Tissue Engineering) . These techniques have demonstrated the effectiveness of JACC in both animal models5,6 and clinical settings,2-4,7 ensuring reproducibility and reliability in our methodology. The Orthopaedic Journal of Sports Medicine, 13(12), 23259671251374880 DOI: 10.1177/23259671251374880 􀀂 The Author(s) 2025 Responses to Specific Comments Foreign Body and Thickness Effects of Nylon Sutures. We agree with Dr Qingyu Xu’s comments regarding this concern. Based on the studies by Katsube et al6 and supporting clinical literature,2-4,7 we believe that the influence of suture material and thickness on transplanted cells’ proliferation, as well as on subchondral bone and surrounding tissue repair, is minimal. However, we acknowledge that some practitioners worldwide prefer absorbable sutures due to concerns about potential effects. Future comparative studies are warranted to clarify the extent of these influences. Impact of Defect Diameter and Depth. To evaluate ACI’s efficacy, we adopted a defect model with a 5-mm diameter and a 3-mm depth in the femoral trochlea of Japanese White rabbits, as described in our previous work.5 This osteochondral defect model does not heal spontaneously, allowing us to investigate PRP’s influence on subchondral bone and cartilage repair in a controlled manner. We observed that PRP significantly affected subchondral bone, supporting its potential role in cartilage repair. Potential PRP Loss and Volume Consideration. As shown in Figure 1 of our previous study,5 50 mL of PRP sufficiently filled the cartilage defect area (Figure 1B) and was administered into the collagen membrane and cartilage sheet space in the ACI group (Figure 1D) . While we agree that retaining PRP at the transplantation site is critical, we initially considered using gel-type PRP but ultimately decided against it. Instead, we selected PRP prepared using the double-spin method for its clinical applicability and ease of use. The collagen membrane was used in its dry state, serving as a carrier for PRP impregnation, which contributed to its retention. Our goal was to simulate clinical conditions, where PRP administration is performed concurrently with ACI as a singlestage procedure. This study demonstrated the feasibility and efficacy of this approach. Additionally, we have completed ano

FAQs

What is the main purpose of the study discussed in this response?

The study aimed to test whether PRP could enhance cartilage repair after ACI, maximizing the therapeutic efficacy of current ACI treatment, with cartilage regeneration as the primary outcome.

How do the authors address concerns about nylon suture effects?

They consider the influence of suture material and thickness on transplanted-cell proliferation and surrounding repair to be minimal based on prior studies, while acknowledging some clinicians prefer absorbable sutures and recommending future comparative work.

How does PRP timing affect cartilage repair outcomes in the authors’ additional experiments?

Administration at 2 weeks post-ACI increased chondrocyte density and improved repair outcomes compared with immediate administration, suggesting delayed PRP may have greater therapeutic potential.

Sep 28, 2026

Uploaded by Jordan Avery