Hip Replacement

People who undergo hip or knee replacements are at high risk for developing blood clots during the first several weeks after surgery. How serious is this complication? A research paper published in Current Opinion in Pulmonary Medicine (Sept. 2002) noted that: “Elective total hip and total knee arthroplasty surgeries are associated with an extraordinarily high incidence of asymptomatic venous thromboembolism (VTE). Symptomatic deep vein thrombosis (DVT) or pulmonary embolism (PE) is diagnosed in only 2%-4% of these patients.” That is why orthopedic surgeons frequently prescribe anticoagulants to prevent such life-threatening blood clots. But which is better for this purpose, aspirin or drugs like Xarelto (rivaroxaban)?

Comparing Aspirin to Xarelto (Rivaroxaban):

Canadian researchers wanted to know whether a pricey anticoagulant called Xarelto (rivaroxaban) was significantly better than aspirin at preventing thromboembolism after knee or hip replacement surgery (New England Journal of Medicine, Feb. 22, 2018). Here is how they justified this study:

“Aspirin is an inexpensive, generic, and widely available antiplatelet drug. Clinical trials and meta-analyses have suggested that aspirin may be effective for the prevention of venous thromboembolism postoperatively, but comparisons with direct oral anticoagulants are lacking. We reasoned that aspirin, because of its efficacy, low cost, and well-established side-effect profile, was potentially a good choice for extended prophylaxis after total hip or total knee arthroplasty.”

The Study:

This double-blind, randomized, controlled trial was carried out at 15 university-affiliated health centers in Canada. Over 3,400 patients who had undergone such procedures were given Xarelto for the first five days after their operations. Then, half of them were randomly assigned to continue taking Xarelto while the other half got low-dose aspirin instead.

The Results:

After three months there was no significant difference between the two groups with respect to blood clots. Here, in their own words, are the outcomes reported by the investigators:

“During the 90-day follow-up period, symptomatic proximal deep-vein thrombosis or pulmonary embolism developed in 11 of 1707 patients (0.64%) in the aspirin group and in 12 of 1717 patients (0.70%) in the rivaroxaban group.”

The authors note that aspirin was no better or worse than Xarelto (rivaroxaban).

The Price:

Xarelto costs over $400 a month. Low-dose aspirin would have cost less than a dollar. The authors note:

“In our trial, we found that the inexpensive, widely available generic agent aspirin was not significantly different from the more expensive, direct oral anticoagulant rivaroxaban for the prevention of symptomatic, clinically important venous thromboembolism after total hip or total knee arthroplasty among patients who had received an initial 5-day postoperative course of rivaroxaban. The patients in the two trial groups had low and very similar rates of symptomatic thromboembolic complications during the 90-day follow-up period after randomization (0.64% with aspirin and 0.70% with rivaroxaban, for a difference of 0.06 percentage points…”

What About Hemorrhage?

Surgeons justifiably worry about bleeding after anticoagulant therapy. They do not want their elegant surgery to be undone by hemorrhage. The patient walks a tight rope. On one side are blood clots that can be life threatening. On the other, there are bleeding episodes that can also be very dangerous. The Canadian researchers paid close attention to concerns about hemorrhage.

The authors report:

“Rates of clinically important bleeding complications were less than 1.5% and did not differ significantly between the two groups. All the bleeding events occurred at the surgical site….However, there were suggestions of more major and clinically relevant nonmajor bleeding among patients in the long-term aspirin subgroup, particularly among those who had been assigned to the aspirin group and hence were receiving a second daily dose of aspirin prophylaxis.”

The authors note that it is hard to determine whether the bleeding events were related to the first five days of Xarelto after surgery or the addition of extra aspirin.

What to Make of This Study?

We are grateful to the Canadian Institutes of Health Research for funding this study. In the U.S. we often have to rely on drug company-funded research. Not surprisingly, there are not a lot of head-to-head trials between pricey new medicines and old, inexpensive drugs. This government-sponsored trial raises intriguing questions about new-generation anticoagulant medications, at least for patients getting knee or hip replacement surgery.

Patients should never stop taking an anticoagulant on their own. This new study should allow people to have a thoughtful conversation with their orthopedic surgeon prior to joint-replacement surgery.

Want to Learn More?

We have written about Eliquis (apixaban) and Xarelto (rivaroxaban) side effects at this link:

Some Eliquis and Xarelto Side Effects NOT in the Prescribing Info

You may find some of the comments from visitors to this web site of interest.

Share your own story about Xarelto or Eliquis in the comment section below.

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  1. Rox

    I am very interested in low dose aspirin studies for those at risk for recurring dvt or PE. I have had both, the PE years ago after a 9-hour invasive surgery and dvt recently after leg cast removed. I attribute these blood clots to those situations. Due to my taking Tamoxifen I can only take Pradaxa, which is crazy expensive. I cannot take any supplements due to these two drugs’ interactions. I’ve asked my physician to put me on low-dose aspirin therapy since it works well with Tamoxifen as a boost to fight cancer, but, sadly they want me on the Pradaxa for life.

  2. Marion

    M.B. May 25, 2018, at 12:04pm

    I had a full right knee replacement in April 2013. 24 hours post-surgery blood clots were found in both leg calves. Medical staff stopped all movement and called in my ortho, and a hematologist. I had been placed on Coumadin prior to surgery. After lab work, they found I had Factor V Leiden, genetic blood clot disorder. I was 59 at the time of my surgery so apparently had it all of my life!

    I changed from Coumadin to Xarelto after a few months and have been on ever since. Along with Xarelto, I also take a daily low dose aspirin. My recovery was very slow and painful and I was told that due to the Factor V it would cause my recovery to take much longer than someone without Factor V.

    I have no idea what Xarelto and daily aspirin are doing to my body. All I am told by all physicians is that I must stay on it for the rest of my life because once you have a blood clot, you are then at much higher risk for more. I have never been the same since this surgery. Maybe I should contact the lawyers.

  3. Tim S

    I had bilat Knees done and threw a clot (DVT) and ended up on Xaralto which caused me to begin experiencing shortness of breath and great muscle fatigue..even doing small things..like standing up..docs kept insisting it wasn’t the drug…but when I finally said “enough” and quit the symptoms started receding within 1 day and continued over a very short period to disappear.

  4. dmitryck

    Joe Graedon, thank you for your blog post. Really, thank you! Awesome.

  5. Anonymous, RN
    U$A Healthcare

    In my opinion, Xarelto is a VERY DANGEROUS drug. Even when people stop taking it 4 days prior to surgery, what would normally be an hour in the recovery room, then go to a floor level bed ends up being a blood or albumin transfusion (s), multiple hours getting IV fluid and Arterial line blood pressure monitoring in recovery, then ICU placement. This never gets reported as being CAUSED by Xarelto, but any one working with patients post operatively has PLENTY of dread receiving a patient who had been taking it, even 4 days prior to surgery. My opinions, statements, and observations may not reflects those of my employer. Anonymous, PACU (recovery room) RN

  6. Kristin

    I had two total knee replacements several years ago. After the first one, my orthopedic surgeon prescribed Coumadin for 10 days, and then aspirin. After the 2nd TKR, he prescribed just aspirin, saying that “they” had discovered that it worked just as well as Coumadin in preventing blood clots. I am only one case, but I had no problems whatsoever with either surgery or recovering afterward.

  7. Dot

    This article is not up to your normal standards. Xarelto is a very dangerous drug. There are currently 20,000 Xarelto lawsuits filed against Bayer and Johnson & Johnson & Janssen the manufacturer of Xarelto. Gary Douglas, the lawyer who tried and won the first Xarelto case, presented Bayer internal documents at the trial that revealed that Bayer knew about a much higher bleeding risk and “made a conscious decision not to disclose what they knew.” Frighteningly, people who have taken Xarelto have bled out in the ER because the hospital staff was not able to determine the location of the bleed. For a detailed expose’ of what Bayer knew and when they knew it, please Google and watch “America’s Lawyer” Episode 53.

  8. Grandma

    What about Warfarin, any comments…?

  9. Pat

    I had a full knee replacement in August of 2015 after many years of pain, injections and suffering. I was put on Xarelto following the surgery. My own Dr. Came to see me in the hospital the day after and upon examining me, changed it to regular aspirin. From all I’ve read since that time, it was a wise move on her part and I am grateful.

  10. Larry M
    Raleigh, NC

    Ahh! This week low-dose aspirin was preferred to Xarelto.

    But last week you told us that once you start taking low-dose aspirin, you can’t stop without putting yourself at risk.

    I wonder which is the best course…

  11. Marilyn

    It was recommended that I take a daily aspirin for 3 weeks after my knee replacement. It really bothered my stomach and I was so glad I was allowed to stop. I spend 2 nights in hospital after replacement and d/c home. I live alone (age 70 at time of surgery) so I was very active during my recovery and quickly regained my mobility. Pain level minimal so I took no narcotics and stopped the Tramadol (felt in a fog and nauseous) after 3 days.

  12. Tony

    what’s the point of writing about medicines that 99% of us cannot possibly afford. Only very rich countries can give these two patients on government healthcare. Even in other countries where healthcare is free governments can’t possibly afford to give this a kind of medicine to their people

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