Toward engineering a biological joint replacement.

Osteoarthritis is a major cause of disability and pain for patients in the United States. Treatments for this degenerative disease represent a significant challenge considering the poor regenerative capacity of adult articular cartilage. Tissue-engineering techniques have advanced over the last two decades such that cartilage-like tissue can be cultivated in the laboratory for implantation. Even so, major challenges remain for creating fully functional tissue. This review article overviews some of these challenges, including overcoming limitations in nutrient supply to cartilage, improving in vitro collagen production, improving integration of engineered cartilage with native tissue, and exploring the potential for engineering full articular surface replacements.