(Reuters Health) - People who get surgery to fix a torn Achilles tendon may be less likely to experience repeat ruptures but more likely to develop infections than patients who get nonsurgical treatments, a research review suggests.

The number of surgeries for these injuries has declined in recent years as a result of studies suggesting that operating might not be more effective than alternatives like a walking cast or physical therapy, researchers note in The BMJ.

But Achilles tendon ruptures are also becoming more common, particularly among active middle-aged and older adults, leading some doctors and patients to question whether surgery might still be the best choice for preventing future injuries.

Researchers examined data from 29 studies with a total of almost 15,000 patients and found 2.3 percent of people treated with surgeries experienced another torn Achilles tendon after treatment, compared with 3.9 percent of those who opted for non-surgical approaches.

However, 4.9 percent of surgical patients experienced infections and other complications like blood clots, compared with just 1.6 percent of people who didn’t get surgery.

“These findings indicate that the benefits associated with operative treatment might not always exceed the harm and risk associated with surgical intervention,” said lead study author Yassine Ochen of University Medical Center Utrecht in the Netherlands.

Many patients who tear an Achilles tendon play recreational sports. The tendon connects the heel bone to muscles in the calf and is often ruptured when it is stretched too far - especially in sports that involve jumping, running, pivoting and abrupt stopping and starting.

Weighing the benefits and harms of surgery may come down to how active patients need to be after treatment, and how likely they are to play sports that increase the risk of repeat injuries, Ochen said by email.

“Athletic people may prefer operative treatment to enhance and expedite their outcomes, whereas a sedentary person with limited functional outcome expectations may prefer nonoperative treatment,” Ochen said.

The aim of any treatment is to get the tendon ends together and keep them close to each other as they heal. With surgery, stitches in the tendon keep the ends together; nonsurgical treatments rely on the body’s natural healing ability and count on the tendon ends to remain close together and may use a cast or boot to restrict movements that could separate the ends.

“Healing takes place also with conservative management, but the tendon may heal in a stretched out fashion,” said Dr. Nicola Maffulli, a researcher at Queen Mary University of London who co-authored an editorial accompanying the study.

“If this happens, it is very much like an elongated elastic: it is still connecting the calf muscles to the heel bone, but it does not transmit the force developed by the calf muscles appropriately, and the patient ends up being unable to push off with the affected foot,” Maffulli said by email. “Hopping, running and jumping are difficult or impossible.”

Patients who opt against surgery may do fine with conservative options but need close monitoring to ensure that no lengthening in the tendon occurs as it heals, Maffulli said.

Only 10 of the smaller studies included in the analysis were controlled experiments designed to assess whether surgery might be safer or more effective than alternative treatments.

Another limitation of the review is that too few studies examined how long it took patients to return to work or playing sports, to determine whether there might be a meaningful difference between surgery and other treatments.

SOURCE: bit.ly/2S5Hs4t, bit.ly/2WgbQbK and bit.ly/2B1zpf8 The BMJ, online January 7, 2018.