Study Finds Large Variations in Knee, Hip Replacement Complication Rates

New research suggests that there may be a wide difference in the risk of complications following hip and knee replacements depending on what hospital is used.

In a study published in the Journal of Bone & Joint Surgery, researchers from Yale’s School of Medicine examined variations in hip and knee complication rates at different hospitals, finding that some facilities experience four times higher rates of problems when compared to others.

The scores for different hospitals will be added to the Medicare.gov Hospital Compare database, allowing individuals considering a knee or hip replacement to look up the complication rates by individual hospital.

Researchers said that while they did not find disparities in outcomes based on whether the hospital treated more Medicaid eligible patients or minority patients, there was a wide quality variation in the results at different facilities.

“We found a four-fold difference in risk-adjusted complication rates across hospitals, suggesting some hospitals have substantial room for improvement when it comes to these surgeries,” lead author Dr. Elizabeth Drye, director of the Yale Center for Outcomes Research and Evaluation (CORE) said in a press release. “Hip and knee replacements are high-volume, costly, and beneficial procedures, and we hope our work will improve how well patients recover after having these surgeries.”

The study is a cross-sectional analysis of national Medicare Fee-for-Service data that includes 878,098 Medicare fee-for-service beneficiaries. All of the subjects were 65 or older and underwent either total hip arthroplasty or total knee arthroplasty. All of the surgeries occurred between 2008 and 2010 at 3,479 different hospitals.

The researchers found that there was an overall complication rate of 3.6%. Pneumonia, pulmonary embolism, and infections were the most common complications, in that order. Complication rates for individual hospitals ranged from as low as 1.8% to as high as 9.0%.

A number of high-profile issues with artificial knee and hip implants have occurred in recent years, raising concerns among consumers and the medical community about the risk of complications that may be associated with specific designs or facilities.

In August 2010, a DePuy ASR hip recall was issued by Johnson & Johnson, raising concerns about the risk of early failure associated with metal-on-metal hip implants. As a result of the problems, more than 12,000 DePuy ASR hip lawsuits have been filed throughout the U.S., and Johnson & Johnson has agreed to pay at least $2.4 billion to settle claims.

Many experts have suggested that the only reason patients and doctors in the United States became aware of the complications with the DePuy ASR hips were due to European and Australian joint replacement registries. There were no such registries in the U.S. at the time, but a American Joint Replacement Registry (AJRR) was launched later that year.

In July 2012, post-marketing reports of problems resulted in a recall of Stryker Rejuvenate and ABG II modular hip systems, after it was found that the models were prone to fret, corrode and fail. Although artificial hips are typically expected to last 15 to 20 years, the Stryker Rejuvenate recall came only two years after the design was introduced.

Closer attention to trends in knee and hip replacement complication rates among different hospitals and specific implant designs may help reduce the risk of defective products or surgical practices being used on large numbers of patients.