Stem cell therapies for knee cartilage repair: the current status of preclinical and clinical studies

Background: Articular cartilage damage of the knee is common, causing significant morbidity worldwide. Many adult tissues contain cells that are able to differentiate into multiple cell types, including chondrocytes. These stem cells have gained significant attention over the past decade and may become frontline management for cartilage defects in the very near future.

Purpose: The role of stem cells in the treatment of knee osteochondral defects was reviewed. Recent animal and clinical studies were reviewed to determine the benefits and potential outcomes of using stem cells for cartilage defects.

Study design: Literature review.

Methods: A PubMed search was undertaken. The key phrase "stem cells and knee" was used. The search included reviews and original articles over an unlimited time period. From this search, articles outlining animal and clinical trials were selected. A search of current clinical trials in progress was performed on the clinicaltrials.gov website, and "stem cells and knee" was used as the search phrase.

Results: Stem cells have been used in many recent in vitro and animal studies. A number of cell-based approaches for cartilage repair have progressed from preclinical animal studies into clinical trials.

Conclusion: The use of stem cells for the treatment of cartilage defects is increasing in animal and clinical studies. Methods of delivery of stem cells to the knee's cartilage vary from direct injection to implantation with scaffolds. While these approaches are highly promising, there is currently limited evidence of a direct clinical benefit, and further research is required to assess the overall outcome of stem cell therapies for knee cartilage repair.