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.


OBJECTIVE
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.


METHODS
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.


CONCLUSIONS
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.
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina Rothman Institute Cartilage Center, Rothman Institute, Philadelphia, Pennsylvania john.anderson@rothmaninstitute.com.
John A
JA
Anderson
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
Dianne
D
Little
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
Alison P
AP
Toth
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
Claude T
CT
Moorman
Rothman Institute Cartilage Center, Rothman Institute, Philadelphia, Pennsylvania.
Bradford S
BS
Tucker
Rothman Institute Cartilage Center, Rothman Institute, Philadelphia, Pennsylvania.
Michael G
MG
Ciccotti
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
Farshid
F
Guilak
D000818:Animals; D002357:Cartilage Diseases / Q000628:therapy*; D002358:Cartilage, Articular / Q000293:injuries*; D006801:Humans; D007718:Knee Injuries / Q000628:therapy*; D033581:Stem Cell Transplantation / Q000379:methods*; D014945:Wound Healing / Q000502:physiology
articular cartilage; biologic healing enhancement; biology of cartilage; knee; stem cell therapy