Osteoarthritis, sometimes called “wear-and-tear” arthritis, is the most common form of the disease. Millions of people worldwide are impacted by osteoarthritis, and this is most often felt in the knee joint. According to the Centers for Disease Control (CDC), 27 million people in the U.S. suffer from osteoarthritis, and 1 in 2 people will develop knee osteoarthritis at some point in their lives.
Joints are cushioned by slick, firm cartilage that acts as a shock absorber and allows for smooth, easy movement, but age, activity, and a variety of other factors can lead to the breakdown of cartilage. This breakdown of cartilage leads to osteoarthritis. Patients may experience pain, swelling, stiffness, or tenderness. Eventually, cartilage can wear away completely so movement causes bone to rub directly on bone, which can be excruciatingly painful.
The first line of defense against knee osteoarthritis pain is usually basic lifestyle changes, such as weight loss.
Exercise can help lessen knee osteoarthritis pain as well, as long as it’s light exercise that won’t put too much strain on the joint. Walking, swimming, biking, tai chi, and yoga are all appropriate choices.
Medication, physical or occupational therapy, or a combination thereof can also reduce pain. Corticosteroid injections can be effective, too, but repeated injections of corticosteroids may do more long-term damage to the joint, so these aren’t normally suggested for long-term treatment. Alternative treatments, such as acupuncture or supplements, are also sometimes successful at reducing discomfort.
If knee osteoarthritis pain is resistant to treatments and is interfering with a patient’s overall quality of life, bone realignment or knee joint replacement surgery might be suggested. Both of these surgeries are invasive and carry the same risks as most surgeries, such as blood clots and infection. In bone realignment, or osteotomy, the surgeon cuts away part of the bone in the joint, shifting the distribution of weight. Osteotomy will typically only provide 10 to 15 years of relief before knee joint replacement becomes necessary.
Knee replacement is the act of cutting away the joint and replacing it with plastic or metal prosthetics. Both of these surgical procedures can provide significant relief of knee osteoarthritis pain, but both surgeries have a long and difficult recovery period. Also, the artificial knee joint can sometimes come loose or wear down, necessitating another surgery.
Biological treatment of knee osteoarthritis may provide alternatives to more extreme surgery.
Biological treatments are much less disruptive to patients’ lives than surgeries like osteotomy or knee replacement, and the recovery periods for biological treatments are often much less intense. A more common form of biological treatment for knee osteoarthritis is autologous chondrocyte implantation (ACI). During the first stage of this procedure, a surgeon arthroscopically harvests a small piece of cartilage from the knee, meaning that he or she takes the sample out with a needle.
This sample is sent to a laboratory, where cartilage-producing chondrocyte cells in the sample are isolated and expanded over a period of 4 to 8 weeks. During the next stage of the procedure, a small patch is surgically implanted over the deteriorated cartilage. The expanded cartilage-producing chondrocyte cells are injected under this patch into the patient’s knee, where they adhere to the joint and, over a period of several months, rebuild the cartilage.
After this, the patient must restrict weight-bearing activities for several weeks. The patient will typically be allowed to resume light activity after 6 months, and full activity can usually be resumed without pain after 9 to 12 months. Although ACI has a success rate of approximately 85%, it has a few drawbacks. It requires 2 separate procedures, and the 2nd procedure is an open surgery. Additionally, ACI is quite expensive and often not covered by health insurance.
A newly developed biological procedure utilizing collagen implants could provide a more attractive option for knee osteoarthritis treatment.
Recently, a minimally-invasive biological procedure was developed by the German biotechnology company Amedrix GmbH, with the help of the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB. The Fraunhofer Institute procures, purifies, and processes collagen protein from animal tendons, which are fibrous bands of connective, collagen-based tissue.
Amedrix’s first implant utilizing this collagen was in a gel-like form that was approved for use in the European market in 2012. The gel implant, called ChondroFiller Gel, requires minor, minimally-invasive surgery to insert. Fibrin glue is used to secure the implant to the cartilage defect, and the gel is custom-fitted by the doctor during surgery.
Amedrix has also developed a liquid form of collagen implant, called ChondroFiller Liquid, which received European CE certification in December of 2013. ChondroFiller Liquid can be injected arthroscopically with a specially made, dual-chambered syringe directly into the patient’s knee. Unlike ChondroFiller Gel, the liquid collagen doesn’t require fibrin glue or surgery. 2 minutes after injection, the ChondroFiller Liquid self-forms a dimensionally stable gel on the cartilage defect.
This is a viable option, not only for minor cases of knee osteoarthritis, but also for difficult-to-reach defects, lesions, fissures, and pores in the cartilage.
In both the ChondroFiller Gel and Liquid implants, stem cells and cartilage from the surrounding tissue migrate to the collagen, which stimulates self-healing of the knee’s cartilage. Magnetic resonance imaging (MRI) studies of patients suggest that the cartilage defect will be filled in within just 6 months, which is significantly faster than the current ACI treatments for knee osteoarthritis.
ChondroFiller Gel, while it requires minor surgery, is approved for treatment of defects up to 12 square centimeters in size, making it suitable for more significant injuries or deterioration. ChondroFiller Liquid is more suited for early treatment of cartilage defects or deterioration, as it is only approved to treat defects up to 3 square centimeters.
Both forms of ChondroFiller require just 1 procedure, unlike ACI, and recovery is much faster and less intensive than the recovery for other surgical options. Additionally, both forms of Amedrix’s implants are described as low-priced and covered by health insurance, giving ChondroFiller a significant advantage over ACI.
Could you, or someone you know, benefit from collagen implants for knee osteoarthritis?
Image by Tyler Hitchcock via Flickr