Repairing Knee Damage: The Microfracture Option, Part II

November 24, 2004 11:40 AM

By Jim Brown, Ph.D., Executive Editor, Sports Performance Journal (athletesperformance.com), and Author, Tennis: Steps to Success, 3rd Edition

In the previous column, a procedure to treat knee injuries called microfracture was discussed. It is an alternative surgical technique used when the damage involves loss of articular cartilage all the way down to the bone. Following is a discussion of possible complications, what the rehabilitation process involves, limitations of the procedure, and where to go for additional information.

Possible Complications

Most patients progress through the postoperative period with little or no difficulty. Some may develop mild pain, most frequently after microfracture has been performed on the patella (kneecap) and the groove on the femur in which the patella glides during motion. Small changes in the articular surface of the joint may produce a grating sensation, particularly when the person discontinues use of the knee brace and begins normal weight bearing through a full range of motion. Patients rarely have pain at this time, and this grating sensation typically goes away in a few days or weeks.

Some patients may notice "catching" or "locking" as the ridge of the patella rides over this area during joint motion. They may even notice these symptoms while using the continuous passive motion machine. If this locking sensation is painful, the patient is advised to limit weight bearing and avoid the bothersome joint angle for an additional period. These symptoms usually disappear within three months.

Typically, swelling disappears within eight weeks after a microfracture procedure. Occasionally, swelling recurs between six and eight weeks after surgery, usually when the person begins to put weight on the injured leg. This problem also resolves within several weeks.

Rehab

The rehabilitation program after microfracture is crucial to the success of the surgical technique. The program is designed to promote the ideal physical environment in which the bone marrow cells can move into the appropriate cartilage-like cell lines. When the ideal physical environment is combined with the ideal chemical environment produced by the marrow clot, a repair cartilage can develop that fills the original defect. The specific rehabilitation program for each patient following a microfracture will vary depending on the location of the defect, its size, and whether any other surgical procedure was performed at the same time as the microfracture.

What Microfracture Is Not

Dr. Steadman and his colleagues warn that microfracture is not a cure for osteoarthritis. It a technique to help form a new surface to cover defects. If successful, it minimizes pain and swelling, and helps the joint function more normally. The new tissue that forms after the procedure is not identical to original articular cartilage. It is a hybrid of articular-like cartilage plus fibrocartilage. But hybrid repair tissue is durable and functions much like articular cartilage. Microfracture is being used in the shoulder, the hip, and the ankle, but the long-term effectiveness of the technique in these other joints is unknown. There are no long-term studies available similar to those that have been done to evaluate the procedure in the knee.

Microfracture is not a miracle cure nor is it a practice of alternative sports medicine. But there is ample evidence showing that it is an option that should be considered for many serious exercisers and tennis players. If you are a candidate, consult a sports medicine physician or an orthopaedic surgeon. For additional information about Dr. Steadman and the Steadman-Hawkins Sports Medicine Clinic, go to www.steadman-hawkins.com.

© 2004 HMS Publishing, Inc.
Jim Brown will be contributing new content to this site on a monthly basis. If you have a question for Dr. Brown please feel free to email him at
sportsmed@mindspring.com.


 

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