Home › Blog › AAOS: Certain Patients at Higher Risk for Blood-clots with Knee Arthroscopy

As I’ve blogged before, blood clots in the leg are surprisingly common in knee replacement procedures. This week a large study was presented at the American Academy of Orthopedics that shows blood clots are relatively rare after knee arthroscopy, but some patients are at higher risk for blood clots than others. These patients may want to consider medications to avoid this complication of knee arthroscopy. The main risk factors were older age, longer time in surgery (over 90 minutes), and a patient with multiple other medical problems (including cancer). Age was the most powerful predictor of who will get a blood clot, with patients over 30 being 6 times as likely to get a blood clot compared to a teenager and patients over 40 being 7 times as likely. Being operated on for more than 90 minutes makes you three times as likely to get a blood clot and having cancer will raise your risk about the same amount. Women were 1.5 times as likely to get a blood clot after knee arthroscopy than men. The median time from the surgery until the blood clot was diagnosed was about 10 days. The overall rate of blood clots was about 1 to 3%, so this is still a rare complication of arthroscopic knee surgery.  A separate study presented at AAOS looked at a different dataset and found a 9 times greater risk for patients who had a history or prior blood clots. Also if a patient had any two of these factors they were almost 3 times as likely to get a blood clot due to knee surgery:

-Age over 65

-Being overweight

-Smoker

-Women on birth control pills or hormone replacement

-Bad leg circulation (venous insufficiency)

The upshot? If you have any of these risks factors, ask your doctor if taking blood thinner medications before knee surgery is a good idea.

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile