The goal of this open-label, post-market clinical follow-up study is to demonstrate the safety and performance of ArtiAid® Plus Intra-articular Injection in patients with knee osteoarthritis(OA). The main questions it aims to answer are:

• the safety profile of ArtiAid® Plus;
• the clinical performance of ArtiAid® Plus, such as pain relief and satisfaction of treatment.

Participants will receive weekly injections of ArtiAid® Plus for 3 weeks and be follow-up for 26 weeks.

An open-label study will be performed in single center to monitor about 60 patients with knee osteoarthritis(OA), each treated with 3 injections of ArtiAid® Plus 1.5% (MAXIGEN BIOTECH INC., Taiwan). Follow-up visits will be at 4 weeks, 12 weeks(a telephone contact by the investigator) and 26 weeks after the injections. The primary endpoint of this study is to monitor the adverse events after injecting ArtiAid® Plus. The secondary endpoints of this study are demonstrating the clinical performance of ArtiAid® Plus, such as resting knee pain and satisfaction of treatment by using the visual analog scale (VAS). Analysis of variance (ANOVA) will be applied to the clinical data and T-test will be used to test for the differences between baseline and each visit. The paired student t-test was used to analyze variations in each group over a period of time. Statistical significance was established at p < 0.05.

Inclusion Criteria:

• Subjects aged older than 40 years old.
• Able to sign informed consent prior to the study.
• Subjects have Kellgren-Lawrence (KL) grade 2 to 3 knee osteoarthritis.
• Subjects have failed to respond adequately to conservative non-pharmacological therapy.
• Plasma pregnancy test at screening visit must be negative for fertile female subjects.
• Subjects in stable progress of disease as judged by the investigator.

Exclusion Criteria:

• Subjects with known hypersensitivity to hyaluronate preparations.
• Subjects with infections or skin diseases in the area of the injection site.
• Pregnancy or breast-feeding woman.
• Significant drug, alcohol abuse.
• Joining any clinical trial within 3 months prior to dosing.
• Subjects have traveled abroad within 3 months prior to the screening visit.