Health Rounds: Long-distance running doesn't wear down knees or hips

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By Nancy Lapid

March 9 -

Hello Health Rounds Readers! Good news today: Running is not likely to damage your knees and hips, Omicron is less likely to cause long COVID, and younger men might be able to skip an unpleasant prostate screening test. Also, if you tear a ligament in your knee, surgeons have some advice on when to get it repaired.

In breaking news, see these stories from our Reuters journalists: U.S. officials ignored mistreatment of thousands of beagles by animal breeding company; FDA warns of asthma drug shortage; Pfizer and GSK prepare to launch RSV vaccines in the U.S.

Long-distance running won't wear down your joints

Long-distance running does not cause the sort of wear and tear on the joints that results in knee or hip arthritis, a large study of marathon runners suggests.

"These results stand in contrast to long-established dogma suggesting that running increases risk of developing hip or knee arthritis," the researchers said.

Researchers distributed surveys to roughly 38,000 runners registered for the 2019 and 2021 Chicago marathons and received completed surveys from nearly 4,000.

The runners' average age was 44. Half the runners had completed more than five marathons. Overall, 7.3% reported having osteoarthritis of the hip or knee, or both.

Runners who reported arthritis in these joints were more likely to have a history of injury to the knee or hip, older age, a family history of arthritis, and a higher body mass index, Dr. Matthew Hartwell of the University of California, San Francisco and colleagues reported on Thursday at the annual meeting of the American Academy of Orthopedic Surgeons (AAOS) in Las Vegas.

But cumulative number of years running, number of marathons completed, weekly mileage, and average running pace were not linked with the likelihood of arthritis, they found.

"These findings can be used by healthcare providers across the care spectrum to inform discussions with patients about the risks and benefits of running and as a basis for re-examining existing guidelines around running and joint health," the researchers concluded.

Study finds best window for repair of common knee injury

The timing of surgery to repair a tear in a the key ligament that stabilizes the knee – the anterior cruciate ligament, or ACL – can make a difference in outcomes, researchers reported on Tuesday at the AAOS meeting.

ACL tears are among the most common knee injuries and are particularly likely to occur in athletes playing sports like soccer, football and basketball. Patients often require surgery to regain full function of the knee.

Researchers used a large insurance database to study 11,867 patients who underwent ACL repair surgery between 2015 and 2018. Overall, 76.1% underwent surgery within two months of injury diagnosis. This was most often the case for adolescents with ACL tears.

ACL repair at 6 to 8 weeks after diagnosis carried the lowest risks for requiring additional procedures during the initial surgery and for revision surgery during the next two years, the researchers found.

Surgery done earlier was associated with a greater need for a secondary procedure involving manipulation of the knee under anesthesia or surgical removal of scar tissue in order to regain full range of motion.

As the wait for surgery increased, however, the proportion of patients needing simultaneous repair of torn knee cartilage, or meniscus, also increased, from 9.1% at 2 months to 20.5% when repair was delayed for more than six months after the injury.

"We believe that the data from this large population of patients offers valuable insight on the optimal timing for ACL reconstruction," study leader Dr. Alan Zhang of the University of California, San Francisco told Reuters. "There is a risk for postoperative knee stiffness if surgery is performed too soon, but there are risks for accruing meniscus injuries and ACL graft failure if surgery is delayed for more than 6 months."

Long COVID less likely after Omicron infection

The Omicron variant of the coronavirus is much less likely to lead to long COVID than the original version that started the pandemic, according to researchers who will present their data next month at the European Congress of Clinical Microbiology & Infectious Diseases in Copenhagen.

The study participants - 1,201 healthcare workers from nine healthcare networks in Switzerland - were mainly healthy, young, vaccinated women.

Overall, 157 participants were infected early in the pandemic and 429 had a first infection with Omicron BA.1.

Workers infected with the original wild-type virus were up to 67% more likely to report symptoms of long COVID than those who had not had COVID-19.

However, workers first infected with Omicron were no more likely to report long COVID symptoms than those who had never been infected with the virus.

Among people infected in the first wave, getting vaccinated or getting re-infected with Omicron did not increase their risk for long COVID, the researchers also found.

The findings are "probably due to a combination of the Omicron variant being less likely to cause severe illness than the wild-type virus – we know that long COVID is more common after severe illness – and immunity acquired through previous exposure to the virus," Dr. Carol Strahm of Cantonal Hospital St Gallen said in a statement.

"The results might be different in a sicker, elderly and/or unvaccinated population," Strahm said.

Digital rectal exams not beneficial for younger men

A common but not-so-pleasant method of screening for prostate cancer may not be worthwhile, particularly in younger men, researchers will report on Sunday at the European Association of Urology Annual Congress in Milan.

The digital rectal exam (DRE), in which doctors check the prostate gland for swelling or lumps using a finger in the rectum, may be missing many cancers in their early stages, the researchers found.

They studied 6,537 men who underwent DRE at age 45 and were followed for the next five years. The exams were abnormal in 57 men. Two were found to have cancer shortly afterward; one was diagnosed two years later. Most of the others with suspicious DRE findings turned out to have prostate inflammation or a noncancerous enlargement of the prostate.

Previous studies suggest the prostate cancer rate in these men is likely four times higher than what the DREs detected, the researchers said.

"If the aim of a screening program is to pick up cancers as early as possible and the current screening tool isn't doing that job, then that is a fundamental failure of that approach," said study leader Dr. Peter Albers of Dusseldorf University in a statement.

DRE results are non-suspicious in more than 99% of 45-year olds, and suspicious findings do not lead to a significant prostate cancer detection rate that would justify its use as a stand-alone screening test at age 45, the researchers said.

DRE might fail to detect cancers in younger men because the changes in the prostate may be too slight to detect with a finger, and because some cancers occur in a part of the prostate that cannot be easily reached by a finger, the researchers noted.

"We speculate... that not only is the DRE not useful for detecting cancer," Albers said, "but it may also be one reason why people don't come to screening visits - the examination probably puts a lot of men off." (Reporting by Nancy Lapid; Editing by Bill Berkrot)