Knee replacement may be bad for your heart

Knee or hip joint replacement surgery, known as arthroplasty, may put people at increased risk of heart attack immediately following the operation, warns a new study.

However, the research indicates that long-term risk of heart attack does not persist, while the risk of blood clot in veins and lungs may remain for years after the procedure.

"Our findings provide the first general population-based evidence that osteoarthritis patients who have total knee or total hip replacement surgery are at increased risk of heart attack in the immediate post-operative period," said lead study author Yuqing Zhang, professor at Boston University School of Medicine in Boston, Massachusetts, US.

Osteoarthritis is the most common form of arthritis, and as the joint cartilage and bone deteriorates, knee or hip replacement surgery may be the only option to relieve pain and stiffness, and restore mobility.

Previous studies estimate that 1.8 million arthroplasty procedures are performed each year worldwide, and that number may increase as the population ages.

The present study included 13,849 patients who underwent total knee replacement surgery and 13,849 matched controls who did not have surgery.

Patients were 50 years of age or older and diagnosed with knee or hip osteoarthritis between January 2000 and December 2012.

Findings indicated that 306 patients in the arthroplasty group and 286 in the non-surgical group developed heart attack during the follow-up period.

Risk of heart attack was significantly higher during the first post-operative month in those who had knee replacement surgery compared to those in the non-surgical group, and gradually declined over time.

"The long-term risk of heart attack was insignificant, but risk of blood clots in the lung remained for years after surgery to replace a hip or knee damaged by osteoarthritis," Zhang said.

The findings were published in the journal Arthritis & Rheumatology.