Knee replacement surgery and stem cell therapy serve distinct purposes and are generally not considered interchangeable treatment alternatives. Stem cell therapy is typically not recommended for patients over 60 years of age, primarily because it becomes significantly challenging to obtain an adequate quantity and quality of stem cells in this demographic. Patients requiring knee replacement usually present with extensive damage affecting multiple components of the knee joint. In contrast, stem cell applications are generally preferred for cases where cartilage damage is localized to a specific part of the knee, with other joint structures remaining healthy. The fundamental therapeutic principles of stem cell treatment differ significantly from those of knee replacement. While certain injections, such as hyaluronic acid, may be an option for patients unable to undergo knee replacement surgery, stem cell therapy is often not the preferred choice in such scenarios. Stem cell treatment is most suitable for limited cartilage defects, whereas patients indicated for knee replacement exhibit widespread joint and cartilage degradation.