Surgeons often prescribe expensive anticoagulant drugs after knee surgery to prevent blood clots, but a new study has found that plain aspirin can work just as well.
Blood clots are not common after knee surgery, but the consequences can be serious and even fatal. There are a number of prescription blood thinners, including the oldest, warfarin (Coumadin), and several new ones with varying mechanisms of action.
The study, in JAMA Surgery, used records of 41,537 patients who had knee surgery between 2013 and 2015.
Among those who received no medicine, the rate of thrombosis, the technical term for blood clots, was 4.79 percent; for prescription anticoagulants, the rate was 1.42 percent; and for those receiving both an anticoagulant and aspirin, 1.31 percent developed clots. Using aspirin alone, the rate was 1.16 percent. The statistical differences were insignificant.
Blood thinners can cause bleeding complications, but the researchers found no difference between aspirin and the prescription drugs in the risk for that side effect either.
The senior author, Dr. Brian R. Hallstrom, an associate professor of surgery at the University of Michigan, said doctors chose the medications and that the study is not a randomized trial. For a patient who had a blood clot in the past, he said, he would still use anticoagulants. But, he added, “Most people can get aspirin alone without much concern.”
