An observational cohort study with a large number of patients was conducted to compare the clinical outcomes of treatment with first-generation autologous chondrocyte implantation to that of treatment with autologous bone marrow stem cells. Seventy-two matched (lesion site and age) patients underwent cartilage repair  using chondrocytes or bone marrow stem cells. There was a significant improvement in the patients quality of life after cartilage repair in both groups. However, there is no difference between the two groups in terms of clinical outcomes. The authors concluded that bone marrow stem cells are as effective as chondrocytes for articular cartilage repair, and have advantages in terms of requiring less knee surgery, reduced costs, and minimised donor-site morbidity (Nejadnik et al., 2010)