How to conduct an effective clinical trial of cell based injection therapy for articular cartilage lesions of the knee.

Conducting an effective clinical trial for mesenchymal stem cell therapy in the treatment of osteochondral defects of the knee in the post-traumatic and/or osteoarthritic knee requires consideration of a multitude of factors not only limited to study design, but also mesenchymal stem cell (MSC) formulation and delivery concerns. Considerations include lidocaine as use as a placebo control as well as other intra-articular injection treatment modalities for comparison such as hyaluronic acid and corticosteroid injections. Concomitant delivery with colony stimulating growth factor by which to bolster cellular concentrations of MSC retention with harvest collection is an additional alternative. Delivery methods can include a host of modalities including scaffolds, extracellular vesicles derived from MSCs, and cell encapsulation in hydrogels. Specific considerations of MSC harvesting method, composition, preparation, processing as well as outcome measures of interest all must be reported in granular detail for consistency in reporting among studies.