In 2011, a Malaysian team of doctors, led by Dr. Khay Yong Saw, released a very promising 5 patient case study in which all patients presented with major knee cartilage defects, with 2 of them having grade IV bipolar lesions. Dr Saw tried on them a treatment he had previously experimented with on goats, called "Articular Cartilage Regeneration with Autologous Peripheral Blood Progenitor Cells and Hyaluronic Acid after Arthroscopic Subchondral Drilling" or ACR in short. The results were simply amazing, as histological examination showed that all defects were covered with true hyaline cartilage.
Cartilage defects are one of the trickiest problems orthopaedics have to face. Even a very small cartilage lesion can potentially become larger and larger, eventually leading to deliberating osteoarthritis. Today, the two most common treatments for cartilage defects are microfracture and autologous chondrocyte implantation (ACI). However, none of these two techniques generates normal hyaline cartilage, but a type of cartilage called fibrocartilage. Fibrocartilage is of inferior quality and many patients need to have additional operations later in their lives. This is why the creation of true hyaline cartilage is considered as the epitome of cartilage regeneration research.
In the past, many other researchers have managed to create hyaline cartilage in the lab, however Dr Saw and his team are probably the first ones to create true hyaline cartilage inside a human patient. Their novel treatment was based on the oldest and most widely used cartilage regeneration technique, Microfracture. They enhanced its efficacy using postoperative injections of autologous peripheral blood progenitor cells (PBPC's) and hyaluronic acid. PBPC's is a blood product containing mesenchymal stem cells.
During the study, all patients first had a typical microfracture operation. One week later, 8 mL of the harvested PBPCs in combination with 2 mL of HA were injected intra-articularly into the operated knees of all patients. The patients received another 5 injections on a weekly basis. Later examination, via arthroscopy, confirmed the formation of true hyaline cartilage on all of them.
According to Dr Saw, the technique may be simple but the recovery time is long and time consuming requiring up to two years for patients to fully return to high impact activities (like sports).
Video of a typical microfracture operation
Saw, K., Anz, A., Merican, S., Tay, Y., Ragavanaidu, K., Jee, C., & McGuire, D. (2011). Articular Cartilage Regeneration With Autologous Peripheral Blood Progenitor Cells and Hyaluronic Acid After Arthroscopic Subchondral Drilling: A Report of 5 Cases With Histology Arthroscopy: The Journal of Arthroscopic & Related Surgery, 27 (4), 493-506 DOI: 10.1016/j.arthro.2010.11.054