The tissue that covers the bone surfaces within your knee joints is called articular or hyaline cartilage. Normally, cartilage is a tough tissue that absorbs shock and weight-bearing joint movements, especially during sports activities. However, when the knee cartilage becomes damaged, the damage can lead to progressive breakdown of the joint to the point where the cartilage tissue cannot heal properly.
You may have signs and symptoms of damaged cartilage within your knee joint(s) that usually consist of pain, joint swelling, joint stiffness, and joint dysfunction of both the cartilage and bone. Your doctor may have determined that your knee cartilage is damaged to the extent that you will require surgical repair to replace the damaged cartilage. Untreated knee problems often trigger a cycle of cartilage breakdown and arthritic degeneration. In many patients, this ultimately results in the need for knee replacement.
Replacing lost knee cartilage with tissue grafts may help restore normal knee function and may delay or even eliminate the need for a knee replacement.
Below are some frequently asked questions about cartilage repair with tissue grafts:
The tissue graft procedure is a relatively straightforward cartilage repair surgery. Tissue overgrowth or thickening at the repair site may necessitate a secondary arthroscopy procedure to trim the excess tissue. Some people may exhibit an allergic response to the graft. This may include short-term discomfort and swelling, and potentially an overall rejection of the graft.
No. Tissue grafts will not interfere with future treatment options, such as surgery or knee replacement, should they become necessary.
You will typically start with non–weight-bearing mobility exercises. Your surgeon may also prescribe continual passive motion exercises. These will help maintain your range of motion and shape your new cartilage as it begins to grow. Your surgeon may help manage your postoperative pain, which may be typical of similar orthopedic cartilage treatment surgeries, with pain medications as well.
Complete rehabilitation consists of four phases. Although recovery times vary among individuals, the typical time to recovery is 18 months.
DeNovo NT Natural Tissue Grafts are single-stage surgery where small pieces of juvenile joint cartilage are implanted into the affected area with a simple surgical technique using a natural sticky glue called fibrin. The graft contains living cartilage cells that have the potential to grow and repair the defect area. Animal studies with DeNovo NT Natural Tissue Graft and human clinical experience to date suggest that a three-dimensional repair tissue will fill the defect site, based on postoperative evaluations. The potential benefit of this implant is that it may enable you to return to normal, or near normal, joint function with reduced pain.
Zimmer developed DeNovo Natural Tissue Graft in partnership with ISTO Technologies, a registered tissue bank with the FDA that is accredited by the American Association of Tissue Banks (AATB). The AATB is a private organization that develops standards by which tissue banks and processors operate. These standards are intended to prevent disease transmission and promote quality and safety in cell and tissue banking and transplantation. As part of ISTO's commitment to Good Tissue Practices, DeNovo NT Graft donors are screened and tested for disease pathogens; donors are cleared according to FDA requirements. Each lot of donated tissue is aseptically processed and individually tested prior to release to reduce the risk of bacterial and fungal contamination. The tissue has been demonstrated to be immune privileged (at reduced risk from being rejected by the body). DeNovo NT Graft has been used safely in nearly 1,000 human clinical cases to date (January 2010). In a preclinical horse study, no adverse events or indications of infections or rejections of the human DeNovo NT implant were observed.