As with bone marrow mesenchymal stem cell,  there is a paucity of controlled clinical investigations on regeneration of articular cartilage using adipose stem cells. Pak et al. (Pak, 2011) used autologous  adipose tissue derived stem cells in four patients, comprising two with knee ostearthritis and two with hip osteoarthritis, which produce positive results. Twelve weeks after  treatment, the patient with knee osteoarthritis  showed an increased medial meniscus  height on MRI. A controlled, prospective study using injected adipose stem cells to treat osteoarthritis was performed by Jo et al.