Ask the Doctors March 2005 Issue

Ask Dr. Marks: 03/05

It is now nine months after my total knee replacement and my pain is no better than it was before my surgery. I’m told I may have developed arthrofibrosis. What is it?

Arthrofibrosis is the excessive development of scar tissue and adhesions in a joint that has undergone surgery or has been injured. In the knee, it causes pain and limits both flexion and extension. Arthrofibrosis after a total knee replacement usually occurs when the knee has poor range of motion before surgery. It is a particular problem in knee revision surgery and reimplantation after treatment of an infected knee replacement.

The best treatment for a stiff knee caused by arthrofibrosis is prevention. Physical therapy should begin promptly after surgery and be continued during the postoperative period. If physical therapy fails to achieve a useful range of motion, manipulation may be necessary; while the patient is anesthetized, the adhesions and scar tissue are gently stretched. Manipulation is usually performed three to six months after surgery. If manipulation fails, surgery is sometimes necessary. This can include arthroscopic surgery or an open incision to remove the adhesions. If the knee needs to be opened, the scar should be excised since the skin sometimes adheres to the capsule of the joint. It is occasionally necessary to lengthen the tendon in front of the knee by a quadriceplasty.

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After suffering from rheumatoid arthritis for several years, I’ve now developed peri-odontal disease. Both, I understand, are caused by a disruption of the inflammatory response. Can one cause the other?

Rheumatoid arthritis does not cause periodontal disease, nor does periodontal disease cause rheumatoid arthritis. Some people with rheumatoid arthritis, however, do develop dental problems. Sjögren’s Syndrome, an autoimmune disease in which white blood cells attack the body’s moisture-producing glands, occasionally occurs in patients with rheumatoid arthritis. This condition causes dryness of the eyes and mouth, which can lead to dental problems and periodontal disease.

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Under what conditions is an MRI recommended for identifying the source of knee pain for someone who has had most of his knee cartilage removed? Aren’t x-rays just as reliable?

What you refer to as “knee cartilage” is more properly identified as the meniscus of the knee. Torn menisci are frequently partially or completely excised to prevent pain in the knee. Menisci cannot be seen by conventional x-ray. An x-ray may be entirely normal even when there is a serious problem with the knee’s meniscus. After partial removal, a meniscus can partially regenerate and be torn again. In addition, a torn portion of the meniscus may be retained that wasn’t addressed at the time of the meniscectomy.

Other conditions may cause knee pain, such as the beginning of osteoarthritis or a tumor-like condition called pigmented villonodular synovitis. When there is no obvious reason for knee pain through examination of an x-ray, an MRI is necessary to make a proper diagnosis. If, on the other hand, you mean by “knee cartilage” the articular cartilage of the knee, then weight-bearing x-rays are reliable for articular cartilage evaluation.