Perspective

Rivaroxaban may reduce post-osteotomy thromboembolic events better than aspirin

Prospective, multicenter studies should compare safety and efficacy of different mechanical, chemoprophylactic agents.

CHICAGO — Use of rivaroxaban may reduce the risk of thromboembolic events after osteotomy, according to results presented at the Arthroscopy Association of North American Annual Meeting.

“We still do not know the best answer for deep vein thrombosis [DVT] prophylaxis following osteotomy-type procedures for the knee and this study’s findings suggest rivaroxaban or Xarelto is a reasonable alternative to other mechanical or chemoprophylactic agents for this complex patient population,” Seth L. Sherman, MD, told Orthopedics Today.

Dr. Seth L. Sherman photo
Seth L. Sherman

Aspirin vs rivaroxaban

Sherman and his colleagues compared patients who underwent osteotomy and received aspirin with patients who received rivaroxaban (Xarelto, Bayer Pharma).

“The first group from 2012 to 2014 basically was an aspirin DVT prophylaxis group and then, because of a small string of thromboembolic events, we did our due diligence and decided upon rivaroxaban and then followed the next cohort of patients … out until 2016,” Sherman, co-division director of sports medicine and associate professor in the department of orthopedic surgery at University of Missouri, said.

Primary outcomes included symptomatic DVT and pulmonary embolism (PE). Secondary outcomes were bleeding, infection, hardware failure and nonunion.

In his presentation, Sherman noted the incidence of DVT or PE was 4.8% in the aspirin group and 0% in the rivaroxaban group.

“Overall, the incidence of thromboembolic events in the whole series was quite low, 1.9%,” Sherman said at the meeting. “The relative risk of a thromboembolic event was at least 2.95 times higher for the aspirin cohort.”

The aspirin and rivaroxaban groups showed no differences in bleeding complications, infection, hardware failures and non-unions, he said.

Study of subgroups

Despite the increased cost of rivaroxaban, Sherman said there are substantial advantages to once daily oral dosing. The dose can be doubled for patients with DVT or PE, which eliminates the need for injections at home or in the hospital.

“At the very least, I think our study has shown [rivaroxaban] to be safe to use in this setting of knee osteotomy surgery. If we follow these cohorts forward with bigger numbers and show clear efficacy vs. the aspirin group, then I think the relative risk reduction of thromboembolic events could be useful to surgeons and beneficial to our patients,” Sherman told Orthopedics Today.

Although this study looked at symptomatic events, he said rates of asymptomatic thromboembolic events may be higher than what was reported. Therefore, research should review these rates.

“Additionally, we can consider a small-scale study looking just at higher risk groups,” such as older patients, patients with a history of a clotting disorder or of taking oral contraceptives, Sherman said. “Such an investigation would help determine if medications like rivaroxaban make even a bigger difference in that subset of patients, he said.”– by Casey Tingle

Reference:

Sherman SL, et al. Paper 79. Presented at: Arthroscopy Association of North America Annual Meeting; April 26-28, 2018; Chicago.

For more information:

Seth L. Sherman, MD, can be reached at Missouri Orthopaedic Institute, 1100 Virginia Ave., Columbia, MO 65212; email: dr.seth.sherman@gmail.com.

Disclosure: Sherman reports no relevant financial disclosures.

CHICAGO — Use of rivaroxaban may reduce the risk of thromboembolic events after osteotomy, according to results presented at the Arthroscopy Association of North American Annual Meeting.

“We still do not know the best answer for deep vein thrombosis [DVT] prophylaxis following osteotomy-type procedures for the knee and this study’s findings suggest rivaroxaban or Xarelto is a reasonable alternative to other mechanical or chemoprophylactic agents for this complex patient population,” Seth L. Sherman, MD, told Orthopedics Today.

Dr. Seth L. Sherman photo
Seth L. Sherman

Aspirin vs rivaroxaban

Sherman and his colleagues compared patients who underwent osteotomy and received aspirin with patients who received rivaroxaban (Xarelto, Bayer Pharma).

“The first group from 2012 to 2014 basically was an aspirin DVT prophylaxis group and then, because of a small string of thromboembolic events, we did our due diligence and decided upon rivaroxaban and then followed the next cohort of patients … out until 2016,” Sherman, co-division director of sports medicine and associate professor in the department of orthopedic surgery at University of Missouri, said.

Primary outcomes included symptomatic DVT and pulmonary embolism (PE). Secondary outcomes were bleeding, infection, hardware failure and nonunion.

In his presentation, Sherman noted the incidence of DVT or PE was 4.8% in the aspirin group and 0% in the rivaroxaban group.

“Overall, the incidence of thromboembolic events in the whole series was quite low, 1.9%,” Sherman said at the meeting. “The relative risk of a thromboembolic event was at least 2.95 times higher for the aspirin cohort.”

The aspirin and rivaroxaban groups showed no differences in bleeding complications, infection, hardware failures and non-unions, he said.

Study of subgroups

Despite the increased cost of rivaroxaban, Sherman said there are substantial advantages to once daily oral dosing. The dose can be doubled for patients with DVT or PE, which eliminates the need for injections at home or in the hospital.

“At the very least, I think our study has shown [rivaroxaban] to be safe to use in this setting of knee osteotomy surgery. If we follow these cohorts forward with bigger numbers and show clear efficacy vs. the aspirin group, then I think the relative risk reduction of thromboembolic events could be useful to surgeons and beneficial to our patients,” Sherman told Orthopedics Today.

Although this study looked at symptomatic events, he said rates of asymptomatic thromboembolic events may be higher than what was reported. Therefore, research should review these rates.

“Additionally, we can consider a small-scale study looking just at higher risk groups,” such as older patients, patients with a history of a clotting disorder or of taking oral contraceptives, Sherman said. “Such an investigation would help determine if medications like rivaroxaban make even a bigger difference in that subset of patients, he said.”– by Casey Tingle

Reference:

Sherman SL, et al. Paper 79. Presented at: Arthroscopy Association of North America Annual Meeting; April 26-28, 2018; Chicago.

For more information:

Seth L. Sherman, MD, can be reached at Missouri Orthopaedic Institute, 1100 Virginia Ave., Columbia, MO 65212; email: dr.seth.sherman@gmail.com.

Disclosure: Sherman reports no relevant financial disclosures.

    Perspective
    Brandon J. Erickson

    Brandon J. Erickson

    DVT prophylaxis has been a moving target in orthopedics over the past several years. While many options exist, and most would agree chemical DVT prophylaxis is necessary after osteotomy procedures about the knee, there has been no consensus in the orthopedic community as to the ideal method of postoperative chemical DVT prophylaxis. The authors should be commended for their efforts in evaluating this difficult topic. While the results of the study are interesting and warrant further work, they must be taken in context, as variables such as surgical time, tourniquet time, type of anesthesia (general vs. regional), etc., were not discussed and may have changed during the study period. These factors could have influenced DVT and PE rates. Furthermore, looking at rates of asymptomatic DVT may be a slippery slope, as treatment of DVT is not without consequence, and once a DVT is seen on imaging, it can be difficult to ignore. Xarelto is certainly a viable option in the DVT prophylaxis armamentarium, and larger-scale, randomized studies evaluating both the efficacy and safety of this drug should be undertaken.

    • Brandon J. Erickson, MD
    • Sport medicine and shoulder, Rothman Institute, New York

    Disclosures: Erickson reports no relevant financial disclosures.

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