Cell Transplantation Techniques for Cartilage Restoration.

Focal articular chondral lesions are a common finding among patients presenting with knee pain, which have been reported with an incidence of up to 60% to 65% during knee arthroscopies. When symptomatic and not responding to conservative treatment measures, cell transplantation techniques can offer a valid treatment solution to regenerate cartilage, due to articular cartilage's very limited self-repair capability. Autologous chondrocyte implantation (ACI) has been used clinically for more than 20 years, with short, medium, and long-term clinical outcomes diffusely reported in the literature. To overcome ACI limitations, other cell transplantation techniques have been considered as treatment modalities for cartilage defect repair. Mesenchymal stem cells induced pluripotent stem cells (iPSC); Scaffold-based cell transplantation techniques such as AMIC and LIPO-AMIC procedures, and allogeneic cell transplantation and allograft cell transplantation have, in recent years, become a successful alternative treatment. This article analyzes clinical data and literature findings on the various cell transplantation cartilage repair techniques from bench and bedside, including all the various options for patients with full-thickness cartilage defects, aiming to outline the past, present, and future of cell therapies for articular cartilage defect repair.