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.
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
Sherman SL, et al. Paper 79. Presented at: Arthroscopy Association of North America Annual Meeting; April 26-28, 2018; Chicago.
Seth L. Sherman, MD, can be reached at Missouri Orthopaedic Institute, 1100 Virginia Ave., Columbia, MO 65212; email: firstname.lastname@example.org.
Disclosure: Sherman reports no relevant financial disclosures.