Millions of aging people are plagued by arthritis in the knees, and two new studies offer insight into what might - or might not - help curb the condition.
Both studies were presented this week at the American College of Rheumatology's annual meeting in San Francisco.
One study found that a popular therapy, steroid drug injections, do nothing to slow progression of osteoarthritis in the knee.
This type of treatment is common, but has never been specifically tested, and there are concerns about its safety, according to a team led by Dr. Tim McAlindon, chief of rheumatology at Tufts Medical Center in Boston.
His team tracked outcomes for 140 people - mainly overweight white women - with knee pain who averaged 58 years of age.
The patients received either injections of the steroid triamcinolone hexacetonide, or placebo injections of saline, every three months for two years.
While the steroid injections were deemed to be safe, they did not improve long-term outcomes of pain, mobility or joint damage compared to the placebo, the Boston researchers reported.
But two experts who reviewed the findings said that steroid shots may still have a place in knee arthritis care."It is widely accepted that these injections do not alter the natural progression of knee osteoarthritis, but are used for symptom reduction," noted Dr. Neil Roth, an orthopedic surgeon at Lenox Hill Hospital in New York City.
In fact, he said, there is no injection that halts progression of knee osteoarthritis. Presently, however, steroid shots "are helpful in alleviating the pain associated with arthritis inflammation," Roth said.
Dr. Calin Moucha is chief of adult reconstruction and joint replacement surgery at Mount Sinai Hospital in New York City.
He agreed with Roth that "steroid injections should continue to be used for temporary symptom relief in patients with moderate to severe osteoarthritis who are trying to postpone knee replacement surgery."
Moucha also believes that healthy weight loss and "low-impact aerobic physical activity" can help ease the discomfort of knee arthritis.
The Boston researchers agreed that steroid shots may have a place as a short-term method of pain relief.
"Additionally, the dose was fairly small [40 milligrams], and we might have seen greater effects with a higher strength formulation," McAlindon said in a meeting news release.
Other treatments for arthritic knees may be on the horizon, however. A second, small study found that injections of ozone gas into the joint reduced pain and improved movement for people with knee osteoarthritis.
The Brazilian trial included 63 patients who received injections of ozone gas into the knee and a control group of 35 who received injections of air. Previous research has suggested that ozone, a naturally occurring gas, may help reduce inflammation.
The patients who received the ozone gas showed significant improvements in pain, physical function, overall health and quality of life, compared to those in the control group, the researchers said.
However, there were no major differences between the two groups in the amount of time it took them to stand up, walk, return and sit.
Researchers Carlos Cesar Lopes de Jesus and Virginia Fernandes Moca Trevisani, of Federal University of Sao Paulo's Paulista School of Medicine, believe that the ozone injections may ease pain for patients and delay the need for joint replacement surgery.
However, they added that further research is need to confirm these findings and to determine whether ozone could offer an alternative treatment.
Roth agreed that the research is promising but preliminary.
The use of ozone injections is "interesting in concept," he said, but the study did have some flaws.
"The authors do not differentiate the levels of osteoarthritis for these patients and it is difficult to know if they are testing predominantly lower levels of arthritis," Roth said.
The therapy "certainly needs further study to see what type of patients, if any, would truly benefit from the injection of ozone gas into the knee," he said.
Experts note that data and conclusions presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.