There has been a dramatic drop in death rates following hip replacements in England and Wales.
A report published in The Lancet found that between 2003 and 2011 the chance of death within 90 days decreased more than halved from 0.56% to 0.29%.
According to the researchers, fitter patients with better physiotherapy could be behind the decrease.
And simpler treatment options could reduce the risk further, the researchers from the universities of Bristol, Oxford, East Anglia and Exeter said.
Data from the UK’s joint replacement database showed that 1,743 patients died within 90 days of surgery over eight years.
In Total hip replacement: mortality and risks the researchers found that in 2004 24,723 patients had hip replacement surgery and 139 of those died within 09 days.
But in 2011, there were 60,727 hip replacement operations and 164 patient deaths.
The study said: "More recent generations of old people... are generally fitter and less frail than old people at the start of the study.
"Likewise, other aspects of surgery and anaesthesia have improved sufficiently to account for the change in mortality rates."
A spokesperson from Arthritis Research UK said: "This is great news for people in the UK who have osteoarthritis and require hip replacement surgery.
"Although not everyone who has arthritis will need hip replacement surgery, for many people, it's their only hope to reduce the pain, disability and stiffness associated with the disease.
"There are however always risks associated in having major surgery such as hip replacement surgery, so we advise people to discuss these risks with their surgeon before they decide to have a hip replacement."