Cartilage 101: painful knees and what can be done for them

By Jeremy Stevens MD Special to PRIME The kinds of questions I get from patients about knee problems are all too common: "Doc, my MRI showed a torn cartilage in the knee, do I have to have surgery? Didn't I read that doctors can grow cartilage now, is that true?," asks one. "Another doctor told me I had 'worn out my cartilage'and now have 'bone-on-bone arthritis' He's talking about a knee replacement.is there any other option?," asks another. As an orthopedic surgeon I spend much of my day trying to explain the various options to treat disorders related to cartilage damage or wear. Much of the confusion is related to our generic use of the term "cartilage" to refer to many very different anatomic structures. Most people know, for instance, that they have cartilage in their nose and ears. Some have heard that the disks in their backs are made of it. It is found, most famously, in our joints in our knees, hips, shoulders, etc. "Cartilage" is the single term we use for the various types of connective tissue composed of collagen fibers and/or elastic fibers in the body. The three main types are; elastic cartilage, hyaline cartilage and fibrocartilage. Cartilage and the knee In the knee, the ends of the bone are covered with "articular cartilage"- a hard, smooth surface, composed of hyaline cartilage, that helps the joint move smoothly. The knee also has two "meniscal cartilage", composed of fibrocartilage, these are softer, semi-circular, structures that act to distribute the bodies weight. So when you read the sports page about athlete with "torn cartilage" what he probably has is that he has a tear of the meniscal cartilage. This usually means an arthroscopic surgery where a small camera is put into the knee through very small incision. The torn piece is usually cut away because the meniscus has a poor blood supply and only very specific types of tears can be sewn back together. The recovery is usually very fast and you will probably see him back on the field in eight to ten weeks. On the other hand, when your 60-year-old uncle is told he has "worn out cartilage with bone-on-bone arthritis" what we usually mean is that he has, over a lifetime of use, worn thin the articular cartilage that covers the ends of the bones. This can be a difficult problem. If the area of damage is small, an Orthopedist can try to smooth any rough edges in an arthroscopic procedure called a chondroplasty. If the lesion is all the way through the cartilage to the bone he or she can drill tiny holes (called a microfracure) to try to stimulate healing with a temporary cartilage- called fibrocartilage. Unfortunately, this temporary cartilage isn't very durable and often patients are still left with pain. There are new techniques that allow us grow new cartilage using harvested cartilage cells, called chondrocytes, or transfer undamaged cartilage either from places in your own knee or from a cadaver. These procedures involve several surgeries and can be very expensive. Worse still, most people's cartilage lesions aren't confined to small focal areas. Because of these reasons, these "cartilage growing" procedures that you might hear about on TV are rarely done. Cartilage and arthritis Most people who have arthritic wear of the cartilage have lost of cartilage in large areas over several spots in the knee commonly on the inside of the knee and under the knee cap. Early arthritis is commonly treated with non-steroidal pain medications, such as the over-the-counter brands Motrin or Alleve. If the pain is very severe and interferes with one's daily activities sometimes a knee replacement is considered. The knee replacementArticle provided by Jeremy Stevens MD Baystate Medical Practices: Valley orthopedic Surgeons and Sports Medicine 51 Sanderson St 1B Greenfield MA 01060 413-773-2220