Cartilage restoration isn’t a particularly new idea in medicine, but as with most treatments, it’s constantly evolving into new and improved ideas and products. When I first started talking with my surgeon about this possibility, he suggested that I get a second opinion from another specialist in the practice who encouraged me to start doing research on a couple different things: glucosamine and chondroitin, DeNovo, and tibial tubercle transfer (TTT).
I’d actually already started to read about cartilage restoration, and I was familiar with autologous chondrocyte implantation (ACI). From my perspective–that of a science nerd–the procedure sounded pretty interesting. It’s a 2-step process during which a surgeon essentially takes a sample of your own cartilage, sends it to a lab where it’s multiplied, and then re-implants the cartilage cells into the defect. This means that you’re having two separate surgeries. The first is an arthroscopy where the surgeon goes in to make sure you’re a candidate for the procedure, cleans up what he can, and takes samples of your cartilage from non-weight-bearing places in your knee. These samples are sent to the lab where they are magically grown into millions of new cells. The second surgery is an open procedure where the incision is much larger than the small ones used during arthroscopy. I’m not all that familiar with these things, so this second surgery sounds pretty complex because the surgeon not only implants the new cells into the cartilage defect, he also covers it with a periosteal patch that is generally taken from somewhere on the shin bone (the periosteum is a thin covering on the outside of your bones). See what I mean? It was intimidating to read all this info. If you want to know more about it, you can see Olympic swimmer Dara Torres talk about her experiences with ACI.
When I met with my OS, he explained we weren’t talking about ACI; instead, we were talking about DeNovo. More specifically, DeNovo NT Natural Tissue Graft. According to the manufacturer’s website, the product “is a juvenile cartilage allograft tissue intended to provide surgeons with an early-intervention option for the repair of articular cartilage.” Basically, that means it’s an option for repair before you might have to think about the more invasive, long-term options like partial joint replacement. This graft is fixed in the cartilage defect with fibrin glue, so there is no need for the surgeon to take a periosteal graft to cover the implant. And it only requires one surgery, instead of two. Add in the fact that it’s much more cost-effective (read cheaper) than ACI, I feel like there are a number of reasons this sounds like a better option for me.
This procedure is still relatively new. The surgical technique was made available in 2009. Most insurance companies consider DeNovo investigational, especially when it’s used anywhere other than the femoral condyle. It doesn’t have FDA approval, but it’s a product that doesn’t require approval to be on the market because it meets the criteria to be identified as a tissue. This means it’s considered an allograft (simply meaning tissue from a donor) and regulated the same way. Regardless of its status, De Novo has been noted for having positive results in the scientific literature.
One of the earlier publications for minced articular cartilage concluded that, while there was evidence that this implant produces hyaline-like cartilage (more like the cartilage that you’re born with), further clinical studies were needed. I haven’t been able to find just too many published articles about the clinical studies for DeNovo NT, but the anecdotal evidence seems positive. Enough so that I could make the decision to move ahead with my own surgery.