Success With Total Hip Replacements Linked to Surgeon Volume

Surgeons who perform more hip surgeries per year have fewer complications.


For restoring function and reducing pain, total hip replacement surgery is one of the most successful, cost-effective and safest options available – yet surgery-related complications do occur. A study published in the journal BMJ in 2014 found that patients whose surgeons perform more than 35 total hip replacements (THR) per year – roughly three or more per month – have fewer complications compared to patients whose surgeons don’t meet that threshold.

Researchers at the University of Toronto in Canada analyzed the administrative health records of 37,881 people with osteoarthritis from the province of Ontario who got their first THR between 2002 and 2009. They pulled data on the rates of complications – including venous thromboembolism (blood clots) or death within 90 days of the surgery, as well as infection, dislocation or revision within two years of the surgery. They gathered information on patient characteristics, such as age, socioeconomic status, additional health conditions and frailty.

The researchers matched the patients – both those with and without complications – to their surgeons, and looked at the annual number of total hip replacements performed by those surgeons.

They calculated that patients whose surgeons had performed more than 35 THR in the prior year had a 30 percent lower rate of early dislocations or revisions compared to patients whose surgeons had performed 35 or fewer procedures. Even for surgeons under the 35-a-year threshold, the risk of complications continued to rise as surgery volume fell. In other words, surgeons doing 25 surgeries a year, for example, had fewer complications than those performing only 10 a year.

Previous studies found that complication rates after total joint replacement vary widely by hospital, but generally are lower in hospitals with a higher volume of surgeries. One study – published in Arthritis & Rheumatism in August 2011 – found that when it came to total hip replacements, hospitals that do more than 200 surgeries a year have significantly fewer complications than those with lower volume.

“Although higher complication risks were seen with low surgeon volume, a surgeon’s overall experience (measured in years of practice) did not appear to be a factor. “We were surprised, but it was interesting to see that experience was not necessarily the driver of lower complications,” explains the lead researcher of the study, Bheeshma Ravi, MD, PhD, a resident physician at the University of Toronto. “It really suggests that it is the act of performing the surgery over and over again, and doing so in the recent past.”

The finance website NerdWallet – which “hires nerds to analyze complex decisions” – did something similar recently in the U.S., after the Centers for Medicare & Medicaid Services released large amounts of physician data to the public. NerdWallet crunched the numbers on more than 3,400 orthopaedic surgeons and came up with 50 as the number of hip surgeries a surgeon should perform per year to be considered “high volume.”

But Dr. Ravi says he believes his findings suggest patients should feel comfortable asking about an individual surgeon’s track record instead of simply looking at how many procedures are done annually at a particular hospital.

“Patients should feel empowered to ask how many procedures surgeons have done in the last year and see if those numbers are reassuring to them. You don’t necessarily need someone who does 200 or 300 a year, but our study suggests that it might be less than ideal to go to someone who only does a few a year,” he says.