The elevated risk of pulmonary embolism (PE)  a blood clot that travels from the leg to the lungs  following total joint replacement (TJR) surgery has been well established, yet little is known about the natural course and timing of this potentially fatal condition.

In the study, "Pulmonary Embolism Following Total Joint Arthroplasty: When Do They Occur?", presented at the 2012 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS), researchers reviewed the records of 25,660 patients who received TJR between 2000 and 2010. All patients received the anticoagulation (blood thinning) drug Coumadin immediately following surgery and each was monitored, but not screened, for PE. Pulmonary embolism occurring within 90 days of the joint replacement was documented.

The median occurrence of PE was two days following surgery, with 254 out of 286 cases of PE (88.8 percent) occurring within the first seven days after surgery. Based on the findings of this study, anticoagulation treatment beyond seven days may not be necessary.