Current approaches to regulating osteoarthritis primarily focus on symptom management; however, these methods often have significant side effects and may not be suitable for long-term care. As an alternative to conventional treatments, injecting stem cells into knee joint cartilage is a promising option for repairing damaged cartilage. In this review, we outline the general procedure for stem cell treatment of knee joint cartilage regeneration, emphasizing the potential of intra-articular stem cell injections as a therapeutic option for osteoarthritis. We examined and summarized patient evaluation and preparation for knee joint stem cell therapy, stem cell harvesting, stem cell preparation, injection procedures for stem cell therapy, post-injection care and monitoring, potential outcomes of stem cell therapy, and considerations and risks associated with stem cell therapy. Overall, stem cell injections for knee joint cartilage damage represent a promising frontier in orthopedic care. They offer potential benefits such as pain and inflammation reduction, promotion of cartilage repair and regeneration, and the possibility of avoiding more invasive treatments such as knee surgery. Ongoing collaboration among researchers, clinicians, and regulatory organizations is crucial for advancing this field and translating scientific discoveries into effective clinical applications.