Note: As a member and incoming chairman of the Public Relations Committee for the American Orthopaedic Society for Sports Medicine, I want to highlight key findings from the AOSSM 2011 Annual Meeting in San Diego this week.

Venous thromboembolytic events (VTE, or blood clots) after knee arthroscopies are fairly uncommon, with most studies showing that they occur in less than 1% of the surgeries. However, they are dangerous conditions if they do occur. A new study presented at the American Orthopaedic Society for Sports Medicine’s Annual Meeting in San Diego sheds light on possible risk factors for VTE.

Investigators at The Mayo Clinic in Rochester, Minnesota studied 12,595 patients who underwent knee arthroscopy surgery over a 20-year period. 43 VTEs occurred, which equates to roughly 0.3% of these surgeries. They found several common risk factors among the 43 cases where a VTE occurred. The most common were a history of cancer or history of a prior VTE. Also having two of the following risk factors – regular tobacco use, body mass index over 30, age over 65, use of oral contraceptives or hormone replacement therapy, and chronic venous insufficiency – also increased the likelihood of developing a blood clot. Tweet these risks.

Knee arthroscopies are among the most common operations in orthopaedic surgery.

Knee arthroscopy, where the surgeon looks in the knee with a scope to treat meniscal tears or other problems in the joint, is one of the most common surgeries in all of orthopaedics. While 0.3% is a low risk in terms of percentage, it is not insignificant when one considers how many of these surgeries are performed annually. Also, these are potentially very dangerous problems. A blood clot in the deep veins of the legs can break free and travel to the lungs. These pulmonary embolisms, like what Serena Williams reportedly suffered, are even potentially fatal.

This study highlights the need for patients and doctors to thoroughly go over risks of the surgery, especially looking for risks for developing blood clots. Patients should give all pertinent medical history. Having all the information can help the patient and surgeon decide if prophylactic medicine is warranted to lessen the chance of these events. Also, they need to realize that while short and fairly straightforward, knee arthroscopy is more than “just scoping the knee.” It is real surgery with real risks.

Diane L. Dahm, an orthopaedic surgeon at The Mayo Clinic and one of the study’s authors, points out, “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.”