Bone and cartilage defects are common features of bone fracture and joint diseases, such as rheumatoid arthritis or osteoarthritis, that have great social and economic impact on the aging occidental population. Despite progress in orthopedic surgery, bone and cartilage repair is a major challenge as large defects will not spontaneously heal. Recent investigations on the stromal mesenchymal stem cell (MSC) offer a new perspectivefor bone and cartilage tissue engineering. However, the standard offull healing is extremely demanding and may be achieved through the engineering of MSCs combined with scaffolds and growth factors as recombinant proteins, or using a gene therapy approach.