Primary osteoarthritis is a debilitating disease characterized by extensive damage to the joints and excruciating pain leading to loss of activity and depression. Despite advances in diagnosis, the quest for the development of a disease-modifying osteoarthritis drug has proven unsuccessful. Human cartilage only has limited regenerative potential. Transplantation is a promising strategy given the high proliferative capacity of MSCs and their potential to differentiate into cartilage-producing cells - chondrocytes. The acquisition of MSC does not require invasive surgical intervention or cartilage extraction from other sites as required by other cell-based strategies. The investigators inject allogeneic human mesenchymal stem cells to the cartilage lesions in patients via intra-articular injection method, and to investigate the efficacy and safety.

Osteoarthritis is one of the commonest diseases in the world, with a global disease burden of 83%. Plain radiograph remained the main modality in diagnosing osteoarthritis. Chondrogen is a mesenchymal stem cell-derived from umbilical cord tissue product. The mesenchymal stem cell is used for the study because of its ability to proliferate and differentiate into various tissues such as chondrocytes, adipocytes, and osteocytes. Various clinical studies have been conducted for arthritis, orthopedic, joint, and cartilage.

This study will enroll 100 patients age 30-70 years old. They will be divided into 2 groups which are the group which will receive the investigational drug (ChondrogenTM and HA) and another group will receive a placebo (saline and HA). It will be a randomized double-blinded study where the participants and the investigator would not know what are the things being received. This study will be conducted for 24 months. The injection will be given on the baseline day after screening the volunteers. The patients will be assessed on VAS, WOMAC, IKDC, KOOS PROMIS29, the interleukins, and MRI.

Inclusion Criteria:

• 30-70 years old
• No serious infection, chronic diseases, diabetes and tuberculosis
• Idiopathic or secondary osteoarthritis of the knee with grade 1-3 defined by the modified Kellgren-lawrence classification
• Written informed consents were obtained from all subjects.

Exclusion Criteria:

• Pregnant or lactating women
• Women of childbearing potential unwilling to use two forms of contraception
• Cognitively impaired adults
• Presence of large meniscal tears
• Inflammatory or post-infectious arthritis
• More than 5 degrees of varus or valgus deformity
• Kellgren Lawrence grade 4 osteoarthritis in two compartments in persons over 60 years of age
• Intra-articular corticosteroid injection within the 3 previous months
• Major neurologic deficit
• Arthroscopy during the previous 6 months
• Poorly controlled diabetes mellitus
• Immunosuppressive or anticoagulant treatment
• NSAID therapy within 15 days prior to inclusion in the study
• Serious medical illness with a life expectancy of less than 1 year
• Prior admission for substance abuse
• Body Mass Index (BMI) of 40 kg/m2 or greater
• Patient receiving experimental medication or participating in another clinical study within 30 days of signing the informed consent

The outcomes assessor will help to screen the participants and send them to the clinical investigators for further medical screening. The participant's personal details will be private and confidential to the outcomes assessor.