Hallym University Kangnam Sacred Heart Hospital

"Weight Loss of 5 Kgs Eases Half of Arthritis"

-A discussion between Dr. Eduardo Salvati, a leading expert on Arthroplasty at Weill Cornell Medical College, and Dr. Jun-Dong Chang, former president of The Korean Hip Society-

As Korea is fast-approaching an aging society, more cases of arthroplasty are being reported. Approximately 19,000 cases of total hip arthroplasty and 50,000 cases of total knee arthroplasty are conducted each year in Korea. Dr. Eduardo A. Salvati, a leading authority in "personalized medicine" by each patient's generic profile who is Professor of Orthopaedic Surgery and Director Emeritus of the Hip and Knee Service, Hospital for Special Surgery (HSS), Weill Cornell Medical College, visited Korea to attend the 6th Hallym-NYP-Columbia-Weill Cornell International Symposium held on April 4. In a U.S. News & World Report annual survey of "America's Best Hospitals," the HSS was ranked number one in the field of Orthopedics. Dr. Jun-Dong Chang, Director of Arthroplasty Center (Hangang Sacred Heart Hospital) and former President of the Korean Hip Society, has called on Dr. Salvati to discuss the present practices and likely future developments in arthroplasty-Ed.

Heavy Sports Activity and Squatting Remain Problematic

Dr. Chang: Osteonecrosis of the femoral head is the most common cause for total hip arthroplasty in Korea. Degenerative hip arthritis comes next. In contrast, degenerative arthritis occupies the highest rate for total knee arthroplasty in both Korea and the United States. Statistically, one-third of people who are aged 45 or older experience degenerative arthritis, and most of those aged 65 have pain and malfunctioning.

Dr. Salvati: In the U.S., osteoarthritis is the main cause. They are mostly caused by the aging and degeneration of cartilage. An increase in sports population is another. Sports activities such as football and basketball put heavy pressure on hip and knee joints, and running repeats such pressure on joints. Hip functions as a leverage. Walking creates a load on joints of an average twice to three times of one's weight, whereas running and jumping generates a load of five to ten times of one's weight. Thus, cartilage is under heavy pressure.

Dr. Chang: We need to avoid running and tennis that produce overload on joints. Instead, aerobic exercises such as walking, swimming and indoor cycling are recommendable. Additionally, the strengthening of quadriceps muscle that stretches knee will protect the joints. A weight loss of five kilograms will reduce pain by 50 percent. By contrast, a weight gain increases a load on hip and knee joints three times. Thus, weight control is the best way to prevent arthritis.

Dr. Salvati: Some Asian life styles such as squatting and sitting on the floor require the bigger range of motion and give rise to joint damage compared with those of Westerners'. It may influence the postoperative results as well.

Dr. Chang: When squatting on the floor, an impingement occurs between stem and cup in arthroplasty. Wear-generated particulate debris is the main cause of periprosthetic osteolysis, thus leading to prosthetic loosening. Therefore, for Asians who are accustomed to squatting and sitting on the floor, a more precise implantation is necessary. In the past, the durability of implants was not long enough. For this reason, surgery was recommended only when pain becomes overwhelming. But recent advances in surgical techniques and materials have significantly lengthened its durability. To improve one's quality of life, the cases of arthroplasty for even young people are on the increase.

Personalized Medicine by One's Genetic Profile

Dr. Salvati: In the field of arthroplasty "personalized medicine" in which the treatment and prophylasis are tailored according to the patient's genetic profile is increasingly noteworthy. If the patient's risk factors are detected before surgery, side-effects and complications can be significantly reduced. If such risk factors as thromboembolism and metabolic response to Warfarin (anti-coagulant) are known in advance, dose adjustment of medicine would be possible to reduce complications. In the past, thromboembolism was as high as surgery infections. Death rates were high as well. An analysis of the patient's genetic profile has now reduced the rates of deep vein thrombosis from 40 percent to 0.6-2.4 percent.

Dr. Chang: Fortunately, the rates of thromboembolism are as low as one percent in Korea. One cautionary note should be made, however, that changes in dietary patterns and environment point to the growing importance of customized treatment by the patient's genetic profile.

Prosthetic Components for Koreans' Physical Profile Needed

Dr. Salvati: In the 1970s, the Dana Center was set up in the Hospital for Special Surgery (HSS) to custom-design and manufacture prosthetic components. Even until the early 1980s, only a few prosthetic components available fit the patents with anatomical abnormalities or deformed joints. Nowadays the market for prosthetic components has so grown as to make an array of products. In cases of revision arthroplasty, however, a high rate of bone loss calls for custom-made prosthetic components.

Dr. Chang: Due to differences in physical and anatomical profile between Westerners and Koreans, it is necessary to develop prosthetic components that fit the Korean people.

Dr. Salvati: The longevity of prosthetic components is still hard to predict, especially over the long term. The use of new materials, which have low rates of wear, would reduce particulate debris, thus decreasing inflammatory responses and osteolysis. Total hip arthroplasty creates an uneven load so that the bones without loads will be weakened-i.e., resorption of bones-and adversely affect the longevity of prosthetic components.

Dr. Chang: In the past, prosthetic components lasted 10 to 15 years on average. But new materials such as highly cross-linked polyethylene, new ceramics and metals have become available. It is highly likely that developments in technology and materials will significantly extend their durability. In the near future, advances in computer, robotics, and bio-friendly materials will make arthroplasty stronger and more durable.

[Ten Tips to Prevent Knee Arthritis]

1. Repeating exercise and rest at a short interval is more effective than an occasional long exercise.
2. Obesity is the main cause of hip arthritis; thus it is important to maintain one's optimal weight.
3. It is necessary not to lift a heavy article, which puts overloads on joints.
4. Squatting or kneeing down on the floor should be avoided.
5. Aerobic exercises are recommendable; swimming is good if knees are under pressure.
6. A periodic exercise for strengthening of quadriceps femoris is commendable.
7. Frequent ventilation is necessary, and indoor humidity should be 40 percent or less; indoor temperature should be 20 degrees or higher.
8. Heavy drinking should be avoided.
9. Take a balanced diet.
10. A protective brace or a cane will reduce loads on joints.