The use of autologous chondrocyte transplantation for the treatment of osteoarthritis: a systematic review of clinical trials

Tissue engineering and cartilage transplantation constitute an evolving field in the treatment of osteoarthritis, with therapeutic and clinical promise shown in autologous chondrocyte implantation. The aim of this systematic review is to explore current clinical trials that utilized autologous chondrocyte transplantation (ACT) and assess its efficacy in the treatment of osteoarthritis. PubMed, Ovid MEDLINE, and Google-Scholar (pages 1-20) were searched up until February 2023. Inclusion criteria consisted of clinical trials that involve autologous cartilage transplantation for the treatment of osteoarthritis. Clinical, imaging, arthroscopic, and histologic outcomes were assessed. A total of 15 clinical trials, involving 851 participants, were included in the study. All trials utilized ACT in the treatment of knee osteoarthritis through varying scaffolds: collagen-based (10 trials), polymer-based (2 trials), hyaluronic-acid based (2 trials), and spheroid technology (1 trial). Clinical improvement of patients undergoing ACT was noted in 14 trials; five showed superior clinical outcomes compared to the control group, while one showed inferiority compared to mesenchymal stem cells. Postoperative imaging was utilized to assess the degree of cartilage regeneration in 11 trials. Ten trials showed signs of cartilage recovery with ACT, four trials showed no difference, and two showed worse outcomes when compared to controls. Second-look-arthroscopy was performed in three trials, which reported varying degrees of improvement in cartilage regeneration. Histologic analysis was performed in four trials and generally showed promising results. While improved clinical outcomes were demonstrated, conflicting findings in postoperative outcome analysis raise questions about the unequivocal utility of ACT. Additional research with control groups, randomization, and appropriate blinding is required.