**5. Conclusions**

In this study, Kartigen® containing CPs was proven safe and free of adverse events, such as infection, inflammation, joint adhesion, loose body, or tumor formation.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/polym13183029/s1. Table S1: Inclusion and exclusion criteria, Table S2: Scheduled visits of the study design, Table S3: Adverse events, Figure S1: Flowchart of this clinical trial.

**Author Contributions:** H.-C.L. and F.-H.L. conceived the project. H.-C.L., Y.-L.L., C.-C.Y. and T.-S.T.L. wrote the article. C.-C.Y. and M.-C.Y. supervised the preparation of Kartigen® and conducted immunohistochemical staining. H.-C.L. performed the surgery and collected clinical information. C.-H.C. and J.-H.W. interpreted the arthroscopic and histology images. T.T.-F.S. assessed the radiological study (MRI). H.-C.L. performed arthroscopy. H.-C.L. supervised the project. All authors have read and agreed to the published version of the manuscript.

**Funding:** The study was funded by Kartigen Biomedical Inc.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the the Taiwan Food and Drug Administration (TFDA, study number 1076026300) and by the Institutional Review Board of Taiwan Adventist Hospital (IRB number: 105-B-09).

**Informed Consent Statement:** Informed consent was obtained from all patients involved in the study. Written informed consent was obtained from the patients.

**Acknowledgments:** We would like to convey our sincere appreciation to the data and safety monitoring board consisting of Yi-Sheng Chan at Chang Gung Memorial Hospital, Chun-Hsiung Huang at Mackay Memorial Hospital, and Chih-Hao Chang at National Taiwan University Hospital. We thank Ying-Tai Jin at Taiwan Adventist Hospital for assessing the immunohistochemical analyses.

**Conflicts of Interest:** C.C. Yen is a manager of Kartigen Biomedical Inc.
