435 - Single Stage Cell-Based Cartilage Repair

and rotational position, is tedious work. The complexity is compounded further when multiple graft plugs are required to repair an asymmetrical defect. This procedure also raises questions about the usefulness of removing cartilage from one area of the knee in order to repair another. Still, even with all those laborious requirements considered, the OATS procedure is one of the more effective therapies currently being used. According to surgeons who specialize in sports medicine such as Dr. Aaron Krych at the Mayo Clinic in Rochester, Minnesota, 66% to 91% of patients receiving current articu- lar cartilage restoration techniques return to playing sports at their preinjury levels. 3 This rate of success is significant, but the process continues to be laden with the issues previ- ously mentioned. He, and other surgeons at Mayo Clinic, such as Dr. Daniel Saris, are currently working on a new treatment that will address some of the issues for this patient population and, as of September 2019, they were in the pro- cess of trialing a technique known as RECLAIM. 10 R E C L A I M Recycled Cartilage Auto/Allo Implantation, or simply RECLAIM, is a technique used to repair the damaged cartilage of the knee. It is a single surgery procedure that involves removing the patient’s own cartilage, combining it with donated stem cells, then returning the mixture into the affected area. It is a cell-based therapy and is specifically designed to treat the younger patients that engage in higher levels of activity than older patients do. Cell therapy, in gen- eral, isn’t a replacement for total joint arthroplasty but more of an option for younger patients who lack comorbidities. Patients with obesity and early onset degenerative diseases such as osteoarthritis, for example, won’t do well with this type of therapy. Recycling live cartilage from donor patients during other procedures such as a TJA is an important function of this process. While the donor tissues as a functional group are damaged, many of the individual cells within the tissues are still viable. During a total knee arthroplasty (TKA), pieces of the articular surface are resected. Most of these pieces still have good cartilage on them which can be donated by that patient. Research has shown that healthy cells from a damaged area can grow if provided a healthy environment. 6 The viability of the donated knee cartilage is assessed using Z-stack confocal imaging with fluorescent live/dead assay. The good stem cells are separated from the bad ones and stored in a bone bank as allogeneic stem cells. Mesenchymal stem cells (MSCs) are adult stem cells which can be isolated from human and animal sources. Human MSCs (hMSCs) are the non-haematopoietic, mul- tipotent stem cells with the capacity to differentiate into mesodermal lineage such as osteocytes, adipocytes and chondrocytes, as well ectodermal (neurocytes) and endo- dermal lineages (hepatocytes). 9 For the purposes of this article, hMSCs may be referred to as MSCs or simply stem cells. S U R G I C A L P R E P A N D P O S I T I O N I N G A basic, minor orthopedic instrument set should be ade- quate for this procedure along with a special RECLAIM set. Preferences will vary, but the Certified Surgical Tech- nologist should have at least an extremity drape, impervious stockinette, self-adherent wrap, suction, Bovie, #10 and #15 blades on #3 knife handles, Senn retractors, rakes, Army/ Navy retractors, small Hohmann retractors, a small Weit- laner self-retaining retractor, Adson forceps, Ferris Smith forceps, hemostats, Kochers, and needle drivers on the back table along with the special RECLAIM instrument set. The Certified Surgical First Assistant will position the patient similar to a knee procedure such as an arthroscopy: supine with the ability to flex the leg and manipulate the knee in a way that exposes the articular surface. Hair may be removed with clippers as needed and a tourniquet should be applied around the thigh proximally. The skin will be prepared with a surgical prepping solution from the incision site at the knee proximally to the tourniquet then distally to the foot including the toes. T H E P R O C E D U R E The RECLAIM procedure itself begins with a small incision in the knee and the affected area is exposed with retrac- tors. Once identified, the focal cartilage defect is outlined using an instrument known as a cookie cutter and a mallet. The area is then debrided with curettes. If the cookie cutter instrument is not available, then the defect can be debrided by other means such as with a #15 blade. The chondral tissue is collected for the lab where it is enzymatically dissolved until single chondrocytes are avail- able. The viable autologous cartilage cells are identified as described previously and combined with the donated allo- geneic mesenchymal stem cells in a ratio of approximately one to ten 6 ; one-part autologous cells to 10 parts allogeneic. The auto/allograft is then returned from the lab to the operating room, combined with a fibrin glue to create an | The Surgical Technologist | MARCH 2020 110