Q. We keep reading about different athletes who have had microfracture surgery for their knee, some of whom have come back to play greatly and others have come back but continued to have knee problems. What is microfracture surgery?
A. In the knee joint, there are two types of cartilage. The more frequently injured type of cartilage in an athlete is the meniscal cartilage, which is a C- or O-shaped shock absorber between the two bones that act as a cushion. When the meniscus tears, this can usually be fixed and in most circumstances the athlete can return at a relatively high level within one to four months, depending on the size and orientation of the tear.
The second type of cartilage, known as articular cartilage, lines every bone in our body. This is best pictured as the rubbery stuff on the end of a chicken bone. If a divot of the articular cartilage occurs down to the underlying bone, this is by definition an area of osteoarthritis.
Microfracture surgery has limited applications but it is used for defects usually a half inch or smaller by making holes in the bone at the bottom of the defect, attempting to allow a fibrocartilage to grow in and fill in the space. The size and the location of the articular cartilage defect frequently determines the likelihood of success of the procedure.
A recent study in professional athletes revealed that 40 percent of the athletes who received microfracture surgery return to play at their previous level, 40 percent return to play in a diminished capacity and 20 percent were unable to return to professional sports. Even if successful, the fibrocartilage that fills the defect is not as durable as the original articular cartilage and can break down.
There is a great deal of research being done in this country and throughout the world for this particular problem in an effort to re-grow articular cartilage in a less invasive manner and with a higher rate of success.
Dr. Harlan Selesnick is team physician of the Miami Heat and director of Miami Sports Medicine Fellowship, Doctors Hospital. Send your questions to HarlanS@baptisthealth.net