Knee and hip implant patients face increased risks for blood clots following surgery, according to new study findings published in the Journal of the American Medical Association (JAMA).
Doctors have long known that dangerous blood clots can occur after joint replacement surgery of the knees or hips. Now a new study is showing some worrisome figures.
One in every 100 patients who undergoes knee replacement and one in every 200 undergoing hip replacement surgery will develop a blood clot before ever leaving the hospital, say WebMD and USA Today. The dangerous blood clots are known as venous thromboembolsm.
Deep venous thrombosis (DVT) can form, as they self-describe—deeply in veins. DVTs tend to develop in the leg and become significantly risky when the DVT dislodges, moving through the bloodstream, until it blocks blood flow to the lungs—a pulmonary embolism, said US News.
DVT signs can include swelling, tenderness, and pain with ankle flex, said Dr. Joel Buchalter, an orthopedic surgeon at Somers Orthopaedic Surgery and Sports Medicine Group in Carmel, New York, wrote US News. “If a person has any of these symptoms, an ultrasound exam can rule a blood clot in or out, but many times blood clots have no symptoms. Some people have a great-looking leg and have a blood clot and don’t even know it,” he added.
“Actual rates in hospitals might indeed be higher,” said researcher Jean-Marie Januel, PhD, MPH, RN, senior researcher at the Institute of Social and Preventive Medicine at the University Hospital of Lausanne in Switzerland, wrote WebMD.
Januel told WebMD that “Actual rates in hospitals should be monitored and made available to patients.”
The team researched the medical literature to find studies that assessed the risk of blood clots after knee replacement or hip replacement surgery. They focused on studies that looked at clots that occurred before leaving the hospital.
They evaluated the results of 47 studies. Most were clinical trials. Of the 47, 21 studies included patients having hip replacement, 20 included those having knee replacement, and six included both. The studies included nearly 45,000 patients.
One unexpected finding: the risk of deep vein clots was higher after knee replacement than hip, the researchers say. Other studies have found that the clots are more common after hip surgery when the period after the hospital stay is included.
And even worse, explained US News, the blood clot rates occur despite treatment to prevent DVTs. All of this is cause for concern because joint replacement procedures—conducted to repair joints that are injured or arthritic—are on the rise and, more-and-more, being conducted on younger patients, said WebMD.
Knee replacement surgery and hip replacement surgery are done to repair arthritic or injured joints. The number of these surgeries has increased in recent years. The surgeries are also being done on younger patients.
About 230,000 hip replacement surgeries were done in 2007, according to the CDC. And, more than 600,000 knee replacement surgeries were done in 2009, according to the Agency for Healthcare Research and Quality.
And although the 1 in 100 statistic is high, the actual rate may be higher, because it does not extend past the hospital stay. And, the actual risk for a blood clot can be as many as 12 weeks later.