Scale Predicts Joint Surgery Complication Risk

Which patients are at risk for complications following hip or knee replacement surgery? Two studies at the University of Pennsylvania Perelman School of Medicine have identified ways to identify candidates who are at risk for complications following replacement surgery.

“There is a need to better identify and predict post-operative complications so we can intervene and provide timely follow-up care, ” said Gwo-Chin Lee, M.D., assistant professor of Orthopaedic Surgery and senior investigator for both of the studies. “Total hip and knee replacements are very common, but they also can pose significant health risks to certain patients, especially older adults.”

In one study, Lee’s team examined the results of 1, 012 patients who underwent total hip or knee replacements over a 10-month period. Seventy patients developed serious complications. Most were cardiopulmonary problems.

Of those 70 patients, 11 suffered setbacks within 24 hours and 59 developed problems more than 24 hours later. If the 59 patients had undergone same-day or short-stay surgery, they would have developed the complications at home and been placed at even greater risk.

As a result of the findings, the researchers developed a scale that will allow orthopedic surgeons to determine if a patient is a candidate for same-day or short-stay procedures, or if that person should be admitted for traditional-duration surgery and recovery.

Patients who have at least one risk factor, such as chronic obstructive pulmonary disease (COPD), congestive heart failure, coronary artery disease, or cirrhosis, should not be considered for either outpatient or overnight-stay total knee or hip replacement.

In a second study, Lee and Maxwell Courtney, M.D., studied the records of 738 patients who had undergone the same types of hip or knee replacement surgery. They found that those who had to be admitted to intensive care or critical care after the procedures had a history of COPD, congestive heart failure, coronary artery disease, chronic kidney disease, needed medications to raise their blood pressure during the procedure, or they lost more than 1, 000 milliliters of blood during surgery.

Based on their findings Lee and Courtney developed the Penn Arthroplasty Risk Score (PARS) to predict which patients would require intensive or critical care after either surgery. “Under the previous model, one in four patients were preemptively admitted to the ICU, ” said Lee. “However, we found that only 22% of the patients ultimately required such stepped-up intervention. By incorporating certain factors into the model, such as significant blood loss and the need to raise the patient’s blood pressure, we have refined the selection criteria for post-surgery admission to the ICU.”

Officials at the hospital believe that use of the PARS tool will result in fewer patients being routinely admitted to intensive care and critical care units after joint replacement surgery, which will result in lower costs without compromising patient safety. It will also ensure that scarce critical care beds are available for those who need them most.