Previous cancer history increases chances of clotting disorders after knee surgery, study suggests

A history of cancer was a significant risk factor for developing blood clotting issues following knee arthroscopy, according to a study being presented at the American Orthopaedic Society for Sports Medicine's Annual Meeting in San Diego. Researchers from the Mayo Clinic in Rochester, Minnesota analyzed the records of more than 12,000 patients who had undergone the common knee procedure.

"A history of malignancy has not been widely recognized as a significant risk factor for developing a VTE (venous thromboembolytic event) following knee arthroscopy," said Diane L. Dahm, MD, Associate Professor of Orthopaedic Surgery at the Mayo Clinic. "VTEs are a rare but potentially serious complication and our research may help doctors better analyze when thromboprophylaxis therapy is necessary and when it isn't."

Dahm and her colleagues analyzed the records of 12,595 patients who underwent knee arthroscopy between 1985 and 2005. Forty-three cases of VTE occurred (1 in 294 surgeries). Of the 43 cases, several risk factors were associated with the individuals who developed a clotting issue, including cancer (4), prior VTE history (8) and history of two or more of the following other risk factors - age greater than 65, BMI greater than 30, use of oral contraceptives or hormone replacement therapy, regular use of tobacco, and chronic venous insufficiency.

"As patients with a history of cancer are clearly more likely to develop VTEs following surgery, more careful monitoring and initiation of thromboprophylaxis therapy may be justified in order to help prevent this potentially life threatening complication" said Dahm.