An on-going clinical trial to assess the results of articular cartilage regeneration following subchondral drilling into chondral defects followed by post-operative intra-articular injections of autologous peripheral blood stem cells (PBSC) in combination with hyaluronic acid (HA).
180 patients with full thickness chondral defects during arthroscopic surgery were treated with multiple subchondral drilling. Clinical cases vary from isolated chondral lesion to cases with multiple kissing lesions requiring ligament reconstruction and longitudinal axis correction. Following surgery, the operated knee was placed on Continuous Passive Motion (CPM) two hours per day for a period of 4 weeks and was on partial weight bearing for up to half the body weight for the first six weeks. Autologous PBSC were harvested by the process of apheresis one week after surgery. 8mls of the harvested PBSC in combination with 2mls of HA were injected into the operated knee one week after surgery. The remainder of the harvested PBSC were divided into vials and cryopreserved for future injections. A total of a five weekly intra-articular injection of PBSC in combination with HA were injected into the operated knee. Serial MRI scans were performed to document articular cartilage regeneration. Five patients underwent second look arthroscopy with chondral core biopsy. Patients were followed up for a period of 6 to 30 months.
MRI scans showed satisfactory healing of the subchondral bone and filling-in of the chondral defects indicating articular cartilage regeneration. Second look arthroscopy with a 2mm chondral core biopsy on five patients confirmed articular cartilage regeneration and excellent integration with surrounding native articular cartilage. The sections showed full thickness mature chondrocytes, both singly and in pairs. They exhibit the usual central pale rounded nuclei with perinuclear halo within a pale basophilic ground substance. The predominant background substance was noted to be hyaline cartilage morphologically. Positive staining was evident with Safranin-O and Collagen II. Collagen I staining was limited to the superficial layers. There was no significant inflammation. Patients showed improved IKDC scores post-operatively. Apart from the minimal discomfort of PBSC harvesting and localized pain associated with the intra-articular injections, there were no other notable adverse reactions.
This is a relatively simple and effective method to regenerate articular cartilage as the entire process involves only a single arthroscopic procedure followed by post-operative intra-articular injections of autologous PBSC in combination with HA. The pre-clinical animal work titled “Articular Cartilage Regeneration With Autologous Marrow-Aspirate and Hyaluronic Acid: an Experimental Study in a Goat Model” has been accepted for publication by Arthroscopy: The Journal of Arthroscopic and Related Surgery.
© 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.