BALTIMORE — Early diagnosis of osteo-necrosis, or bone death, by magnetic resonance imaging, a super-sophisticated scanning device, can cut the need for total hip and knee replacements, an internationally known orthopedic surgeon says.
"We can restore the blood supply to the bone while it still has some life in it by drilling a pencil-size hole in the side of the hip or the knee," says Dr. David S. Hungerford, chief of orthopedic surgery at Good Samaritan Hospital in Baltimore. "It's a very simple operation that takes just about 20 to 25 minutes and requires an incision about an inch long."
Hip and knee replacements mean major surgery, with a much slower recovery and much higher cost.
10 Million at Risk
About 10 million Americans are at a substantially higher risk than the rest of the population for osteo-necrosis due to a loss of the bone's blood supply, says Hungerford, who also teaches orthopedic surgery at Johns Hopkins University School of Medicine.
He reported on his first 40 cases at a symposium of leading orthopedic researchers and surgeons from the United States, Canada and Europe.
In 15 cases treated in which no collapse of bone was present, he found that none subsequently needed to have a total knee replacement; 11 of 21 patients in which early collapse already was present have not needed to have a total knee replacement and the remaining 10 got relief but two years later needed a total knee replacement; four remaining patients have not returned for follow-up.
"It's important that we educate physicians and patients that early diagnosis and treatment can alter the course of the disease," he said. "This is not widely known. If we can intervene before the bone starts to collapse and crumble, there's a 75% to 80% chance a total knee replacement can be avoided."
Those who are apt to develop osteo-necrosis take cortisone or steroids for rheumatoid arthritis, lupus, asthma, allergy, eczema and transplants, or consume more than two or three alcoholic drinks a day, he said.
Among steroid users, osteo-necrosis occurs in 1 in 25,000 patients but the disease takes a marked jump in the drinking population, where Hungerford estimates it occurs in 1 in 1,000.
Correlation Not Understood
Cortisone and steroids, particularly in high doses, and more than two or three alcoholic drinks a day can cause pressure to build up in bones, but no one knows why. That, in turn, restricts blood flow and leads to bone collapse.
Patients with this problem will have "a grumbling, kind of an achy type pain" that comes and goes and is usually associated with activity, Hungerford said. If it persists, it is time to see the doctor.
The average age of patients affected is in the 30s, he said. Occasionally, the disease occurs in people who are older.
Hungerford believes the incidence of osteo-necrosis is increasing. That may be because of the magnetic resonance imaging, which can more readily make the diagnosis, or it may be that the total alcohol consumption is rising, he said.