Normally, every joint in your body, including your knee, has a healthy cushion called articular cartilage. This cushion can be damaged under a variety of circumstances resulting in a worn area down to bone (or close to bone). This is called a "chondral defect". It is a major problem which, if left alone, will invariably lead to significant arthritis.
Today we have some amazing options for actually trying to re-grow your joint surface -- something never thought even remotely possible in recent past.
Two common procedures that can get your knee back on track are microfracture and autologous chondrocyte transplantation (ACI). You may have read about these procedures in the sports pages of your newspaper since many professional athletes have undergone them to try to give new life to their worn knees. The recovery can be long, but in the long run, worth it.
The microfracture technique is a simple outpatient arthroscopic surgery in which small puncture holes are placed in the damaged area of joint surface creating vascular channels for stem type cells to populate the defect and eventually reform your joint surface with articular type cartilage.
With autologous chondrocyte transplantation, two surgeries are required but many believe that the eventual joint surface that grows is more durable and more like the one you were born with. The first surgery is a minor outpatient arthroscopic procedure in which some of your own healthy joint surface cells, known as chondrocytes, are taken and sent away to a laboratoryin Boston (Genzyme) where millions of chondrocytes are grown in cell culture (a type of "cell therapy"). The second procedure is a bigger open surgery in which your own cells are now transplanted back into your knee to help form a new joint surface.
With both surgeries, the recovery is pretty long. Since the new growing joint surface is fragile, like a newborn baby, it must be treated with great care. You are on crutches for sometimes up to six to eight weeks. You must also use a continuous passive motion (CPM) machine that rocks your knee like a baby in a cradle. For reasons that we do not entirely understand, the rocking motion of a CPM machine enhances the growth of healthy joint surface or articular cartilage. Physical therapy is usually required, and you can use low impact alternatives to stay fit during the healing process, but you are usually not permitted back to sports for nine months.
Years ago, when I was in my orthopedic surgical training program, which actually included research in articular cartilage storage and transplantation, the bottom-line was that once your joint service was damaged, there was no recovery, no turning back, no way to repair things, and essentially no hope other then eventual joint replacement. Boy, have things changed!
New technologies are around the corner that will make both of these procedures much more effective, with smaller incisions, and quicker recoveries. Until then, be happy that we have made the progress that we have and remember the future is very bright for your damaged joints. Someday, these very technologies will even be used to restore joints damaged by arthritis, giving you back your joint surface rather than a plastic and titanium artificial joint replacement.
