Benchmarks Cited for In-Hospital VTE Post Arthroplasty
For the first time, researchers say they have established benchmarks for the rates of in-hospital venous thromboembolism that occur after total or partial hip arthroplasty and after total or partial knee arthroplasty.
In a meta-analysis of 47 studies published in JAMA that documented venous thromboembolism (VTE) event rates in nearly 45,000 patients who received recommended prophylaxis during hospitalization for knee or hip arthroplasty, investigators estimated that approximately 1 in every 100 patients undergoing knee arthroplasty and 1 in every 200 undergoing hip arthroplasty will develop symptomatic VTE before discharge.
"These estimates are of value to individual patients and clinicians in the consideration of risks and benefits" of the two procedures. They also are important because rates of in-hospital VTE are increasingly used as indicators of patient safety at individual medical centers, even though the expected background rates haven’t been established until now, said Jean-Marie Januel, a registered nurse with the Institute of Social and Preventive Medicine, Lausanne (Switzerland) University Hospital, and his associates.
Mr. Januel and his colleagues analyzed 41 randomized clinical trials and 6 observational studies performed between 1996 and 2011 in which subjects having hip or knee arthroplasty received VTE prophylaxis according to published guidelines, including either low-molecular-weight heparin or inhibitors of factor Xa or IIa.
A total of 22 of the studies were performed in Europe, 14 were in North America, and 11 were in other regions. The mean duration of follow-up after either surgery was 13 days. This included 21 studies of partial or total hip arthroplasty, 20 of partial or total knee arthroplasty, and 6 studies of both procedures, with a total of 44,844 subjects.
There were 443 cases of symptomatic postoperative VTE that developed before hospital discharge: 288 in the 23,475 knee patients and 155 in the 23,475 hip patients. The pooled incidence rates of VTE were approximately 1% after knee arthroplasty and approximately 0.5% after hip arthroplasty. (JAMA 2012;307:294-303). When the data were broken down by type of VTE, the pooled incidence rates were 0.26% for deep vein thrombosis and 0.14% for pulmonary embolism after knee arthroplasty. The corresponding rates were 0.63% for deep vein thrombosis and 0.27% for pulmonary embolism after hip arthroplasty.
The pooled incidence rates of deep vein thrombosis were lower for both knee patients and hip patients when factor Xa or IIa inhibitors, rather than low-molecular-weight heparin, were given for prophylaxis. "However, we cannot make assertions regarding comparative efficacy among treatments, because our meta-analysis did not directly compare [these agents]," they said.
They reported no financial conflicts.