The hospital you choose for hip or knee replacement surgery may play an important role in determining whether you develop postoperative complications, such as pneumonia or wound infections. That’s according to a study conducted by researchers from the Yale Center for Outcomes Research and Evaluation (CORE) at the Yale School of Medicine in New Haven, Conn., in partnership with leading orthopaedic surgeons and government experts. The findings appeared in the May issue of the Journal of Bone and Joint Surgery.

Nearly one million people undergo joint replacement surgeries each year in the United States, according to a Millennium Research Group, a company that analyzes the medical technology industry. The vast majority of these surgeries are successful in reducing pain and restoring function, and most patients recover with few problems, but some patients experience complications related to the operation itself or to postsurgical care. Previous studies have compared surgical outcomes at specialty versus general hospitals, but until now, no one had studied complication rates at hospitals throughout the U.S.

The Yale researchers and their collaborators developed a measure that could be used to rank the quality of care at every hospital performing joint replacement procedures. The measure is based on medical and surgical complications that patients experience that could be attributable to the surgery, such as pneumonia, pulmonary embolism (a blood clot that travels to the lungs), heart attack, sepsis (a potentially fatal reaction to an infection), surgical site bleeding, joint or wound infections, mechanical complications and death.

Yale research scientist and senior study author Elizabeth Drye, MD, says the complications her team decided to focus on were selected because the medical literature and clinical experience indicate they are the most likely to occur after total hip or knee replacement.

To compare the complication rates across hospitals, investigators looked at Medicare fee-for-service data for nearly 900,000 patients 65 or older who underwent elective joint replacement from 2008 to 2010. They focused on 2,832 hospitals that perform at least 25 of the procedures per year.

Overall, complication rates were low. A total of 31,247 patients had one or more complications. The most common were pneumonia (7,555), pulmonary embolism (6,582) and joint or wound infections (5,904). After adjusting for patient age, sex and health status, complication rates ranged from less than 2 percent at some hospitals to 9 percent at others – a fourfold difference in outcomes between the best and worst performers. 

Dr. Drye says the investigators weren’t surprised by the findings.

“We expected to find differences in complication rates across hospitals because of underlying differences in quality of care,” she says.