Study: Avascular Meniscus Can Be Repaired

By Tom Keppeler, Knee1 Staff

Certain tears of the meniscus, the shock-absorbing pad of cartilage within the knee joint, were once considered irreparable by most surgeons. As a result, young athletes with meniscal tears, which often accompany other sports-related injuries, such as tears of the anterior cruciate ligament, would have their menisci surgically removed, leaving them vulnerable to early-onset arthritis.

At the annual meeting of the American Academy of Orthopedic Surgeons earlier this month, orthopedic surgeon and former Knee Care Hero Frank Noyes unveiled a 14-year study that showed great success with repairing meniscal tears that extend into the "avascular zone," an area considered to be unfixable.

Each leg has two menisci (meniscus, plural): the lateral (outside) meniscus and medial (inside) meniscus. The half-moon shaped discs of cartilage both serve the same purpose: to cushion the blow running, walking, and jumping deliver to the inside of the knee joint. Each meniscus is divided into three sections: the first, the vascular zone, has a continuous blood supply and, thus, good healing properties. Athletes with meniscal tears in the vascular zone ordinarily respond well to surgical repair. The middle area of it is known as the gray zone, which has fair healing properties; tears that extend into this zone will usually—although not always—be repaired.

However, the avascular zone, which essentially receives no blood supply, cannot heal on its own. As a result, tears that extend into the area most often result in a meniscectomy, or removal of the meniscus. In 1996, for example, 28,000 patients between 9 and 19 years of age had meniscal excisions, according to the National Center for Health Statistics. Dr. Noyes, who is president and medical director of the Cincinnati Sportsmedicine and Orthopaedic Center, compares removing the meniscus to taking the shock absorbers out of a car—eventually, he says, you'll wear your tires out. "Too often in my practice, I have had to treat patients under the age of 30 with severe arthritis because they had their meniscus removed years earlier," Noyes said in a statement. "At this point, there's little we can [offer them]; a total knee replacement at [such a] young age is not a promising prospect. The impact of being able to save the meniscus in patients is extremely satisfying."

Noyes' approach is to suture the meniscus along both the top and bottom of the tear. Then, a 1½-inch incision is made that anchors the sutures to the bone. The procedure is done during outpatient arthroscopic surgery, which minimizes recovery time and requires that the patient use crutches for four to six weeks. The patient can return to sports about six months after the surgery, Noyes said.

The study followed 61 patients between the ages of 9 and 19 who underwent the study's procedure to repair tears in the avascular zone of their menisci. Four years after the surgery, three out of every four patients were pain-free, suggesting a successful meniscal repair. Noyes estimates that of the 28,000 menisci removed in 1996, half could have been repaired using the suture technique.