New Predictor of Joint Replacement Failure: Pain in Untreated Joint

Adding patient-focused musculoskeletal measures to the standard billing and diagnostic-code data that Medicare used when it released comparative surgical-quality data for total joint replacement procedures in 2013, Patricia Franklin MD MPH has found a new set of indicators for poor results in knee and hip replacement surgery.

She analyzed data from a different source than the Medicare database, using records for roughly 24,000 patients in the FORCE-TJR registry sponsored by the US Agency for Healthcare Research & Quality (AHRQ), a random sample from 150 surgeons in 22 states stratified for a diversity of settings.

Measuring patient-reported indicators, such as self-reported pain and HOOS and KOOS (Hip and Knee Osteoarthritis Outcome Scores, respectively), as primary outcomes, Franklin screened the data for readmission rates and complications 30 and 90 days after surgery.

Besides poorer emotional health, she found, preoperative physical function as well as moderate to severe pain in the non-operated joint were significant predictors of poor outcomes in joint replacement surgery.

Barely hours before she was due to present her study at the Osteoarthritis Research Society International meeting in Seattle, Franklin received an email informing her that the Centers for Medicare and Medicaid Services (CMS) has now decided to add clinical measures such as hematocrit, weight, and values for heart function to the administrative indicators it uses to assess hospital quality according to post-surgery complication and readmission rates.

None of these, however, are musculoskeletal measures, she told the audience with an ironic chuckle. How, she asked, will we actually know which hospitals are best at joint replacement?

Besides improving quality reporting for joint surgery, Franklin said, “my second motivation was to advise surgeons. I also think patients should be informed what their risks are. Our goal is to begin to have some strategy to parse out patients at greater risk.”

Franklin is a professor in the University of Massachusetts School of Medicine, with appointments in the Department of Orthopedics and Physical Rehabilitation, Family and Community Medicine, and Clinical and Population Health Research.

Rheumatologist Jeffrey Katz of Brigham & Women’s Hospital in Boston congratulated Franklin on a “really beautiful study that’s very important to public policy.” But he observed that doctors should resist the urge to focus too closely on the pain in the other joint, which could be a red flag for something other than the actual cause of the failed surgery.

“We see this a lot in risk models that come out,” he said. “They may point out factors that are actually a proxy for something else.”