Meniscal Surgery
Ross Hauser, M.D. Marion Hauser, M.S.,R.D.

Meniscus injuries occur in most sports, but most commonly occur in contact sports. They often occur in combination with ligament injuries, particularly when the medial meniscus is involved. This is partly because the medial meniscus is attached to the medial collateral ligament and partly because tackles are often directed towards the lateral side of the knee, causing external rotation of the tibia.

Injury to the medial meniscus is about five times more common than injury to the lateral meniscus.(1)

By knowing the function of the meniscus, it is possible to predict what will happen when meniscal tissue is shaved or removed. Since it provides some of the nutrition to the articular cartilage, its removal will aid in the demise of the cartilage. If the cartilage is damaged, then the pressures on the bone will be too great and arthritis will soon follow. This is not the only reason why articular cartilage damage is sure to follow after meniscectomy. The removal of the menisci allows too much pressure to be put on the articular cartilage, thus lessening the shock absorption. This is why cartilage damage and proliferative arthritis must be the end result of meniscal removal. No other option is available. If the surgeon removes the meniscus, arthritis is the end result. If that were not enough, the menisci aid in the stability of the knee. If they are removed, the knee is left with too much motion and becomes unstable. This also increases the likelihood of articular cartilage damage and subsequent arthritis.

Arthroscopic shaving and removal of the meniscus would therefore be expected to result in the progression of arthritis in the knee.

Study Shows Increased Contact Stress Pressure after Meniscectomy
There have been numerous studies showing that the contact stress pressure on the articular cartilage significantly increases after meniscal removal. (2,3)

One such study showed that after partial meniscectomy, the contact stress pressures increased by 110 percent and after total meniscectomy they increased 200 percent. Their conclusion was expected. "The contact stresses increased in proportion to the amount of meniscus removed.18 Other studies have shown even greater increases in pressure, causing from a 450 to 600 percent (six times) increase in pressure on the tibia bone and articular cartilage when the meniscus is removed." (4,5)

Menisci are normally shaved or removed because they are believed to repair so poorly. Menisci have poor blood supply. This is one of the reasons they heal poorly. The best treatment option in our opinion is to increase the circulation to the damaged menisci.

Studies Show Meniscal Surgery
Actually Increases Injury
Repairing a meniscal tear with arthroscopy makes conceptual sense, however, this just does not occur often enough to warrant the procedure. In an animal study, only 38 percent of the meniscal repairs actually healed. (6)

To add insult to injury, another study showed that meniscal repair can actually cause a further spreading of the injury to the non-injured meniscal tissue. The authors noted, "It appears that in radial repairs, progressive spreading at the repair site altered normal meniscal geometry and structure." (7)
 
In common language, attempting to repair the area with arthroscopy makes the normal meniscal tissue weaker and further worsens the injury. The authors went on to say, "Meniscal tissue from repaired radial lesions was significantly lower than controls in yield stress, maximum stress, and elastic modulus. The repaired radial meniscal lesions demonstrated abnormal force transmission and energy dissipation behavior qualitatively similar to a complete meniscectomy." (7) This is unbelievable! Repairing a meniscal tear makes the meniscal tissue so weak that it is like having no menisci at all. What a scary thought!

Meniscectomy Causes Arthritis
Repairing meniscal tears does not work; neither does grafting tissue over the tear. In one study on sheep knees, one group received a total meniscectomy, two groups received different grafts, and the control group received no surgery. Guess which group did better? You guessed it! The virgin knee group that was never probed by a scope faired the best. On follow-up x-ray after only 21 months, the control knees had no arthritis, but the meniscectomized knees had significant arthritis in all the compartments of the knee, as well as the grafted knees. The authors concluded, "Knees undergoing each of the three procedures in our study showed significant degenerative changes when compared with the nonoperated control knees. This would suggest that surgical intrusion into the knee predisposes it to osteoarthritic changes." (8) What a shock!

Partial Meniscectomy: More Arthritic Changes Result
Luis Bolano, M.D., and associates at the Oklahoma Center for Athletes and the University of Oklahoma wanted to determine the long-term results of arthroscopic partial meniscectomy. They noted that the short-term results of arthroscopic partial meniscectomy had been excellent-to-good in 80 to 95 percent of patients in the already published studies. (9)

What they found surprised them. The patients, many of whom were athletes, were functioning fairly well. Eighty percent experienced satisfactory results, 66 percent maintained their activity levels, but 26 percent decreased their activity levels after the surgery. Despite the apparent success of the surgery, almost all of the patients showed arthritic changes on x-ray. Forty-one percent had advanced arthritis. The authors noted, "The amount of meniscus removed and the type of tear had a significant effect on the radiographic result." (9)

The problem with arthroscopic surgery is that it does not induce the healing of the menisci. The athlete feels better for a while, but the injured tissue remains injured. This causes the arthritic process to start immediately. If left unchecked, the athlete's abilities will decline, symptomatology will increase, and more arthroscopic or orthopedic surgeries will follow. If the athletes want this, then by all means, continue to be scoped. If they want to avoid arthritis, they must see a Prolotherapist and receive Prolotherapy to stimulate the body to heal the menisci and other injured tissue.

The Outlook is not Good for Post-Surgical Athletes
What is the outlook down the road, 12 to 15 years, for people who have had arthroscopic partial meniscectomies? Not good. In a study of 21 patients who had partial meniscectomy, six needed further meniscal surgery and seven required additional knee surgery. Over 50 percent of the meniscectomized knees needed knee surgery by 12 to 15 years down the road. Eighteen of the 21 patients who underwent meniscectomy had arthritis in the knee. The three with no arthritis were, likely, very inactive people. About 50 percent of the knees, however, had advanced arthritis compared to the non-operated knees. This statement by the authors should be of significance to the athletes, "The activity level of the patients in both groups changed...indicating a downward change from active individual sports, such as tennis, squash, or downhill skiing, to less strenuous physical fitness activities such as cycling, hiking, or cross-country skiing." (10)

Other studies have confirmed similar findings. If no cartilage deterioration occurred before meniscus removal, deterioration will occur after the surgery. (11)

Long-term effects of meniscus removal lead to increased contact stresses and subsequent articular cartilage degeneration. (12-15)

1. (Peterson, L. Sports Injuries. Chicago, IL. Year Book Medical Publishers, 1983; pp. 296-299.)
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3. Brown, T. In vitro contact stress distributions on the femoral condyles. Journal of Orthopedic Research. 1984; 2:190-199.)
4. Radin, E. Role of the menisci in the distribution of stress in the knee. Clinical Orthopedics. 1984; 185:290-294.
5. Seedom, B. Transmission of the load in the knee joint with special reference to the role of the menisci: Part 1. Eng Med. 1979; 8:220-228.)
6. Cabaud, H. Medial meniscus repairs. American Journal of Sports Medicine. 1981; 9:129-134.) adversely influencing mechanical function.
7. Newman, A. Mechanics of the healed meniscus in a canine model. American Journal of Sports Medicine. 1989; 17:164-175.)
8. Edwards, D. Radiographic changes in the knee after meniscal transplantation. American Journal of Sports Medicine. 1996; 24:222-229.
9. Bolano, L. Isolated arthroscopic partial meniscectomy. American Journal of Sports Medicine. 1993; 21:432-437.
10. Maletius, W. The effect of partial meniscectomy on the long-term prognosis of knees with localized, severe chondral damage. American Journal of Sports Medicine. 1996; 24:258-262.
11. Cox, J. The degenerative effects of partial and total resection of the medial meniscus in dogs' knees. Clinical Orthopedics. 1975; 109:178-183.
12. Allen, P. Later degenerative changes after medial meniscectomy. Journal of Bone and Joint Surgery. 1984; 66B:666-671.
13. Appel, H. Late results after meniscectomy in the knee joint. Acta Orthop Scand (Suppl). 1970, pg. 133.
14.Tapper, E. Late results after meniscectomy. Journal of Bone and Joint Surgery. 1969; 51A:517-526.
15. Veth, R. Clinical significance of knee joint changes after meniscectomy. Clinical Orthopedics. 1985; 198:56-60.