Meet MACI: Cartilage repair for long-lasting relief

August 13, 2018 11:06 AM

Dr. Kurtz, MACI specialist in Maine

Meet MACI, the latest upgrade in the world of cartilage replacement. MACI, or matrix autologous chondrocytes implantation, is a technique which uses your own cartilage cells to repair your damaged knee. You can damage your cartilage for any number of reasons, most commonly from repetitive actions or traumatic events. Unfortunately, cartilage doesn’t repair itself, and the pain will only worsen as time goes on. The only way to relieve this pain is through surgery, in which case, MACI may be your best option. MACI will relieve pain and restore your ability to be active, while past cartilage repair procedures were much less durable.


The first step of any process is speaking with your doctor. Factors taken into consideration include your age (MACI is shown to work best for those under 40), the depth and size of the hole, as well as any other surrounding issues. Dr. Anton Kurtz, the only MACI specialist in Maine, believes in looking at the overall picture, from hip to ankle, before zeroing in on the damaged cartilage to ensure that MACI is the right choice for your needs.

Whether or not MACI is right for you depends on the extent of damage to your knee. Most small defects use microfracture surgery, a technique which stimulates new cartilage growth from beneath the bone surface. For a larger defect, you have two primary options, one of which is MACI. Your other option is to replace the damaged cartilage with healthy cartilage and bone, known as OATS, either from your healthy knee or from a donor.


The first step is to take a biopsy (sample of tissue to examine) from your healthy knee cartilage. This sample is sent to a lab in Cambridge, Massachusetts where the chondrocytes (or cartilage cells) from your biopsy are expanded on a sheet of collagen. Six weeks later, the matrix is ready for implantation. This involves shaping the implant to fit within your defect and then attaching it to the damaged area. Throughout the next 12-18 months, the MACI cells adhere to your bone and grow new cartilage where it’s lacking. By the end, you’ve restored your cartilage cells and you can return to the active lifestyle you lived before.


The MACI technique does involve a lengthy rehabilitation process, but it is necessary to ensure optimum recovery. Until the new cartilage cells fully mature, you must treat them gently. Immediately after surgery, it’s important to get your knee moving and wear a knee brace for the first four to six weeks to keep your full weight off your knee. Physical therapy begins as early as your first week after surgery and will continue throughout the recovery process. Over time, you will strengthen your knee and find yourself returning to a full range of motion.

No matter how you injure your cartilage, chances are, you’ll need surgery. If you decide MACI is right for you, understand recovery will be long, but the end results are worth it. By the end, you’ll have regrown your own cartilage, providing you with a more durable solution which allows you to return to an active, and healthy lifestyle.

“I realized that MACI had a lot of potential to become a very important tool in the knee preservation process for a group of patients who are sometimes left without great options for decades,” says Dr. Kurtz, a Spectrum Healthcare Partners orthopaedic surgeon. This new procedure provides a better way to repair cartilage and help patients return to the lifestyle they lived before injury. MACI isn’t going to be right for every patient, but look closely at the research, consult a doctor, and decide if it’s the best treatment for you.