Obesity to Blame for Epidemic of Knee Dislocations, Complications

Obesity to Blame for Epidemic of Knee Dislocations, Complications

Need another reason to keep your weight under control?

Excess weight can cause dislocation of your knee and may even lead to a complication that results in amputation of your leg.

A new study attributes a surge in dislocated knees to the U.S. obesity epidemic.

“Obesity greatly increases the complications and costs of care,” said study lead author Dr. Joey Johnson, an orthopedic trauma fellow at Brown University’s Warren Alpert Medical School.

“As the rate of obesity increases, the rate of knee dislocations increases. The total number of patients who are obese is increasing, so we are seeing more of these problems,” Johnson explained.

Knee dislocations result from multiple torn ligaments. Vehicle crashes or contact sports, such as football, are common causes.

For the study, the researchers analyzed more than 19,000 knee dislocations nationwide between 2000 and 2012. Over that time, people who were obese or severely obese represented a growing share of knee dislocation patients — 19 percent in 2012, up from 8 percent in 2000.

Obesity is also linked to more severe knee dislocations, longer hospital stays and higher treatment costs, according to the study published recently in the Journal of Orthopaedic Trauma.

And the chances that a knee dislocation would also injure the main artery behind the joint and down the leg were twice as high for obese patients than for those whose weight was normal, the findings showed. This severe complication of knee dislocation — known as a vascular injury — can lead to leg amputation if not treated, the study authors said.

Patients with a vascular injury averaged 15 days in the hospital, compared with about one week for other patients. Their average hospitalization costs were just over $131,000 and $60,000, respectively.

The study authors said doctors should be especially watchful for vascular injury in obese patients whose knees are dislocated.

“That subset of obese patients who come in with complaint of knee pain need to be carefully evaluated so as not to miss a potentially catastrophic vascular injury,” said study co-author Dr. Christopher Born, a professor of orthopedics at Brown.

Reducing obesity rates could help reverse the growing number of knee dislocations, the researchers suggested.

More information

The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more on knee problems.

SOURCE: Brown University, news release, Nov. 3, 2017

This Weight-Loss Strategy May Not Help Your Knees

This Weight-Loss Strategy May Not Help Your Knees

Weight loss from dieting can slow the progression of knee arthritis in overweight people, according to a new study.

But losing pounds from exercise alone will not help preserve those aging knees, the researchers found.

Obesity is a major risk factor for painful knee osteoarthritis — degeneration of cartilage caused by wear and tear. Weight loss can slow the disease, but it wasn’t clear until now if the method of weight loss made a difference.

Apparently, it does.

“These results add to the hypothesis that solely exercise as a regimen in order to lose weight in overweight and obese adults may not be as beneficial to the knee joint as weight loss regimens involving diet,” said lead author Dr. Alexandra Gersing.

Gersing made her comments in a news release from the Radiological Society of North America (RSNA). She’s with the University of California, San Francisco’s department of radiology and biomedical imaging.

The study included 760 overweight or obese adults who had mild to moderate knee osteoarthritis or were at risk for it. The participants were divided into a “control group” of patients who lost no weight, and a group who lost weight through either a combination of diet and exercise, diet alone, or exercise alone.

After eight years, cartilage degeneration was much lower in the weight-loss group than in the control group. However, that was true only of people who lost weight through diet and exercise, or diet alone, the investigators found.

Study participants who exercised without changing their diet lost as much weight as those who slimmed down through diet plus exercise or diet alone, but there was no significant difference in cartilage degeneration compared to the control group.

The study was scheduled for presentation Tuesday at the annual meeting of the RSNA, in Chicago. Research presented at medical meetings should be considered preliminary until published in a peer-reviewed medical journal.

More information

The American Academy of Orthopaedic Surgeons has more on knee arthritis.

SOURCE: Radiological Society of North America, news release, Nov. 28, 2017

How You Think About Your Arthritis Makes a Difference

How You Think About Your Arthritis Makes a Difference

How well you cope with knee arthritis depends a lot on your mental outlook, a new study suggests.

Despite often-debilitating pain, people who remain confident in their ability to move about end up more active than their less confident peers, researchers found. Studies have shown that physical activity may be one of the best ways to reduce and manage symptoms of osteoarthritis.

The Pennsylvania State University study was based on 135 adults with knee arthritis.

“On days when patients felt more confident in their ability to be active, they indeed took more steps and spent more time in moderate-intensity activity, despite their level of pain that day,” said study lead author Ruixue Zhaoyang.

What’s more, “this positive effect of patients’ confidence on their actual physical activity was found for patients with varying degrees of pain in the morning,” added Zhaoyang, a post-doctoral fellow with the university’s Center for Healthy Aging.

The researchers also observed that predicting individual activity levels was best done by focusing on someone’s personal confidence, rather than comparing them to someone else.

“It’s all about what you think you’re able to do,” Zhaoyang said.

The findings “suggest that future physical activity interventions for people with osteoarthritis should target patients’ confidence in their ability to be active,” said Zhaoyang.

But the key, she said, will be to focus on boosting each individual’s confidence patterns, and not on some universal benchmark.

Arthritis is a major cause of chronic pain for many adults. The U.S. Centers for Disease Control and Prevention estimates more than one-third of American seniors have osteoarthritis, the wear-and-tear form of the disease. Symptoms typically include joint pain, swelling and stiffness.

Such patients are often caught in a catch-22 situation. While research has shown that physical activity is effective for pain and overall function, the ongoing pain makes it hard to meet federal recommendations for at least 2.5 hours of moderate-intensity activity a week.

Not exercising leads to greater stiffness and deterioration in muscle strength, the researchers said.

For this study, the investigators wanted to see how someone’s “self-efficacy” in the morning affected their day-to-day living with arthritis. This term refers to the degree to which people feel confident in their capacity to do or achieve something.

The researchers used accelerometers to track each participant’s total number of steps and the physical intensity of their daily activities over roughly three weeks.

Each morning the patients also noted how confident they felt in their ability to keep active, their pain level, and their overall mood.

The research team found that those who felt more confident in the morning about their ability to get around did actually move more throughout the day. This was so despite shifting levels of pain, mood or support from a spouse.

The study was published recently in the journal Health Psychology.

Certain Jobs Linked to Raised Risk of Rheumatoid Arthritis

Certain Jobs Linked to Raised Risk of Rheumatoid Arthritis

Rheumatoid arthritis, a painful disease in which a person’s immune system attacks the joints, appears to be more common among people in certain types of jobs, researchers suggest.

The findings “indicate that work-related factors, such as airborne harmful exposures, may contribute to disease development,” study author Anna Ilar said. She is a doctoral student in epidemiology at the Karolinska Institute in Stockholm.

The study looked at more than 3,500 people in Sweden with rheumatoid arthritis, and nearly 5,600 people without the disease.

Among men, those in manufacturing jobs had a higher risk of rheumatoid arthritis than those in the professional, administrative and technical sectors, the findings showed. The risk was twice as high for electrical and electronics workers, and three times higher for bricklayers and concrete workers.

Among women, assistant nurses and attendants had a slightly higher risk, but women in manufacturing jobs did not. The researchers suspect that’s because fewer women than men work in manufacturing.

More study is needed to zero in on the exposures that may be involved, Ilar noted. Potential culprits include silica, asbestos, organic solvents and engine exhaust.

The report was published online Aug. 10 in the journal Arthritis Care & Research.

“It is important that findings on preventable risk factors are spread to employees, employers, and decision-makers in order to prevent disease by reducing or eliminating known risk factors,” Ilar said in a journal news release.

The researchers said they accounted for lifestyle factors associated with rheumatoid arthritis, such as body fat, smoking, alcohol use and education level. However, while the study found an association between certain occupations and rheumatoid arthritis risk, it didn’t prove a cause-and-effect relationship.

Do Your Knees Crackle and Pop?

Do Your Knees Crackle and Pop?

Knees that “pop,” “click” or “crackle” may sometimes be headed toward arthritis in the near future, a new study suggests.

It’s common for the knees to get a little noisy on occasion, and hearing a “crack” during your yoga class is probably not something to worry about, experts say.

But in the new study, middle-aged and older adults who said their knees often crackled were more likely to develop arthritis symptoms in the next year.

Of those who complained their knees were “always” noisy, 11 percent developed knee arthritis symptoms within a year. That compared with 4.5 percent of people who said their knees “never” popped or cracked.

Everyone else fell into the middle. Of people who said their knees “sometimes” or “often” made noise, roughly 8 percent developed knee arthritis symptoms in the next year.

Doctors have a term for those joint noises: crepitus.

Patients commonly complain of it, said Dr. Grace Lo, the lead researcher on the study. She’s an assistant professor at Baylor College of Medicine in Houston.

But until now, it hasn’t been clear whether crepitus can predict symptomatic knee arthritis. That means people not only have evidence of cartilage breakdown on X-rays, but also suffer symptoms from it — namely, frequent pain and stiffness.

“Our study suggests crepitus is not completely benign,” Lo said. “It’s a sign that something is going on in the knee joint.”

Dr. Joseph Bosco, an orthopedic surgeon who wasn’t involved in the study, agreed that frequent crepitus should be checked out.

“A lot of people’s knees ‘snap’ and ‘pop,'” said Bosco, a professor at NYU Langone Medical Center in New York City. “Do they need to run out for knee replacements? No.”

But, he added, “if you experience crepitus regularly, get an evaluation.”

The findings, published May 4 in the journal Arthritis Care & Research, come with some caveats.

The nearly 3,500 study participants were at increased risk of developing knee arthritis symptoms to begin with, Lo explained.

The participants ranged in age from 45 to 79. Some were at risk of knee arthritis simply because of old age, while others had risk factors such as obesity or a history of a significant knee injury.

So it’s not clear, Lo said, whether the findings would translate to — for example — a 35-year-old whose knees crack when she runs.

Plus, even though the study participants were initially free of knee arthritis symptoms, some did have signs of arthritis damage on an X-ray.

And it was in that group where crepitus was a red flag: People who “often” or “always” had noisy knees were nearly three times more likely to develop knee arthritis symptoms as those who “never” had crepitus.

According to Lo, the findings could be useful in everyday medical practice. “If patients are complaining of frequent cracking or popping in the knees,” she said, “get an X-ray.”

If that turns up signs of arthritic damage, Lo said, then the risk of progressing to symptoms in the near future is probably significant.

Unfortunately, there is no magic pill that can stop arthritis in progress. But, Lo said, for patients who are heavy, weight loss can help.

Some, she added, might benefit from strengthening the muscles that support the knees.