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).
The figures are worrisome. 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.
“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. The figures represent estimates following an evaluation by Januel and his team of 47 published studies on blood clot risks following joint replacement surgery.
Januel told WebMD that “Actual rates in hospitals should be monitored and made available to patients.” And, two physicians familiar with the data told WebMD that the estimates may not truly reflect blood clot risks because those risks persist beyond the study period.
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.
The U.S. Centers for Disease Control and Prevention (CDC) estimates indicate that in 2007, alone, approximately 230,000 hip replacement surgeries were conducted, said WebMD. The Agency for Healthcare Research and Quality estimates for 2009 indicate that over 600,000 knee replacement surgeries were conducted.
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.
Dr. John Heit, a cardiologist at the Mayo Clinic in Rochester, Minnesota, wrote an editorial accompanying the JAMA report, said US News. “The authors are trying to estimate the magnitude of the problem among patients who receive the most effective prophylaxis available today. But the risk is actually much higher than the study suggests…. One has to understand the period of risk extends beyond the duration of hospitalization, which these days, is really quite short,” wrote Dr. Heit.
