Question: I’m on a wait list for hip replacement surgery. I’ve read about a minimally invasive operation called the direct anterior approach that apparently results in a faster recovery. Is this the best option?
Answer: In recent years, a growing number of patients have been choosing the direct anterior approach. And it’s certainly true that during the first few weeks and months after the operation these patients tend to get better faster compared to those who have other types of hip replacement surgery.
However, like all medical procedures, it involves both pros and cons. What you need to know is that a landmark Canadian study published in March in the Journal of the American Medical Association identified potential problems with this approach.
“We found that the direct anterior approach was associated with a significantly higher risk of major surgical complications,” says Dr. Bheeshma Ravi, the senior author of the study and an orthopaedic surgeon at Sunnybrook Health Sciences Centre in Toronto.
The complications included deep infections and painful dislocations where the artificial joint pops out of the socket.
Dr. Ravi is quick to point out that the vast majority of patients undergoing a total hip replacement – regardless of the surgical approach – do well and they’re normally happy with the results.
“The hip replacement is one of the most successful surgical procedures in terms of quality-of-life improvement,” he explains. “But when there is a complication, it’s not pleasant. It’s going to be the dominant focus of your life for months because you may need multiple surgeries.”
Before delving deeper into the risks, it’s worthwhile reviewing the two other types of hip replacement surgery commonly performed in Canada.
One is called the posterior approach, in which the surgeon makes an incision, or cut, through muscles on the back of the hip. The other is the lateral approach. It involves an incision on the side of the hip.
In both these procedures, the surgeon has to cut through muscle to gain access to the joint. The worn-out section of the upper thigh bone – the ball of the joint – is then removed and replaced with an artificial part.
This means the cut muscles must heal before patients can experience the full benefits of a hip replacement.
With the anterior approach, by contrast, the surgeon makes an incision at the front of the thigh and then moves aside the muscles and other tissues to reach and replace the joint. As a result, the muscles remain largely intact, which can contribute to a speedier recovery.
To evaluate the three different surgical techniques, the researchers used Ontario health data from 30,000 patients who received total hip replacements between April 2015 and March 2018.
The findings revealed that 2 per cent of patients who chose the anterior (frontal) approach suffered a major surgical complication within one year of their operation compared with only 1 per cent of those who had either the lateral (side) or posterior (back) approach.
The researchers noted that patients who had the anterior approach tended to be younger and in better overall health than those who had the other surgeries. These two factors are usually associated with a lower chance of complications.
So, why was there double the risk with the frontal approach in a comparatively younger, healthier population? It’s possible that the position of the leg during the operation makes it harder for the surgeon to get the artificial ball into the right spot. (Some hospitals use a specialized operating-room table for this procedure but the researchers didn’t notice it made a difference in terms of the complication rate.)
Despite the elevated risks, Dr. Ravi says some patients may still prefer the frontal approach if an earlier recovery is important to them. He adds, though, they should at least be made aware of the potential complications.
Patients should also consider the surgeon’s experience and not just the surgical approach, says Dr. Amir Khoshbin, an orthopaedic and trauma surgeon at St. Michael’s Hospital in Toronto.
He suggests patients may want to pick a surgeon who does a lot of these surgeries – over 100 a year. “Higher-volume surgeons usually have fewer complications and potentially better outcomes,” says Dr. Khoshbin.
On the other hand, by choosing a specific surgeon who might be in high demand, it could add to the length of time you have to wait for your hip replacement.
So, what’s a discriminating patient to do? One important thing to keep in mind is that most people reach the same level of recovery in six to 12 weeks after their operation, regardless of the type of surgery.
In other words, those who have the frontal surgery are off to a faster start but within about three months all patients end up at roughly the same place – provided they haven’t run into surgical complications.