Dr. Blom explains that spinal anesthetics give better pain relief so patients less frequently need opiates, like morphine, after surgery. This is important, he says, because opiates can cause respiratory depression, vomiting and confusion.

These four strategies are not without risks or challenges. In an accompanying commentary, authors point out the posterior approach can be associated with a higher rate of dislocation, which could require revision surgery. Spinal anesthesia has its own side effects and requires highly trained anesthesiologists, which could be impractical. And there is no consensus on the best way to prevent blood clots. The commentary commends the study but notes that “treatment of all patients with the approach proposed in this report might be impractical.”

Among the study’s other findings: The type of implant used for the hip replacement didn’t appear to impact mortality; sicker patients (including those with severe kidney or liver disease, metastatic cancer and congestive heart failure) have a higher risk of mortality, as do older patients; and overweight patients appear to have a lower mortality risk. The authors caution that this last observation could be skewed because they didn’t have BMI data for nearly 60 percent of study participants.

Dr. Bostrom says this study’s findings offer helpful clues to U.S. patients about topics they should discuss with their surgeons before undergoing a hip replacement. “You want the right anesthetic. You want to make sure they are doing something to prevent blood clots, and the time-honored way of approaching the hip through the posterior approach works very well,” he explains.

And though this study is based on data from England and Wales, Dr. Bostrom says it makes sense to assume there has been a similar mortality drop among U.S. hip replacement patients because these four methods are being used at most American hospitals. But the U.S. is still working to create a similar-sized registry that could confirm the findings.

The American Joint Replacement Registry, the official registry sponsored by the American Academy of Orthopaedic Surgeons, launched its current data collection efforts in 2012. Its long-term goal is to capture data on 90 percent of joint replacements done in the U.S., but currently it has data on only about 55,000 procedures. Slightly more than 200 hospitals have signed up for the registry so far. About half are currently submitting data and the others are in the process of setting up a system to do so.

“They are trying to start [a registry] here in the U.S., but we are really far behind,” Dr. Bostrom explains. “That’s really too bad, because we do the most joint replacements anywhere in the world and it’s a very powerful tool to figure out what is and isn’t working for the benefit of our patients.”