By Pat Anson, Editor

Black, Hispanic and Medicaid patients are significantly more likely to be readmitted to the hospital after total joint replacement (TJR) surgery, while women are less likely to suffer complications, according to new studies presented at the annual meeting of the American Academy of Orthopaedic Surgeons in Las Vegas.

In one study, researchers analyzed race and ethnic data on nearly 53,000 patients admitted to Connecticut hospitals for TJR from 2008 to 2012. The average patient was 67 years of age, white, female and covered by Medicare.

Patients who were African-American were 62% more likely to be readmitted to the hospital within 30 days of TJR. Hispanic patients were 50% more likely and Medicaid patients were 40% more likely to be readmitted than patients with private insurance.

"Our study shows that black patients who undergo total knee replacement may have poorer outcomes," said lead study author and orthopedic surgeon Courtland Lewis, MD. "After controlling for two key variables implicated in race and ethnic disparities in hospital readmission -- preoperative comorbidities and type of insurance coverage -- black patients still have a 35 percent higher likelihood of all-cause, 30-day readmission compared to white patients.”

Lewis said the disparity with white patients may be due to black patients having less access to primary care and less communication with health care providers.

Racial disparities in health care have long been documented, including that black patients utilize hip and total knee replacement at rates nearly 40 percent less than white patients, despite having higher rates of osteoarthritis—a leading cause of joint deterioration. Total hip and knee replacements are common surgical treatments for late-stage arthritis.

The overall 30-day readmission rate for patients in the study was about 5 percent. The most common reasons for readmission were postoperative infection, inflammatory reaction due to a joint prosthesis, hematoma complications, and dislocation of a prosthetic joint.

A second study looked at nearly 60,000 knee and hip replacements at a hospital in Ontario, Canada. Researchers found that men were 15% likely than women to return to the emergency department within 30 days of TJR surgery – even though women who had the surgery were older and more likely to be frail. Over half the patients in the study were women.

The findings contradict the theory that TJR is underutilized in female patients because they have worse outcomes then men.

"Despite the fact that women have a higher prevalence of advanced hip and knee arthritis, prior research indicates that North American women with arthritis are less likely to receive joint replacement than men," said lead study author Bheeshma Ravi, MD, an orthopaedic surgery resident at the University of Toronto. "One possible explanation is that women are less often offered or accept surgery because their risk of serious complications following surgery is greater than that of men.

"In this study, we found that while overall rates of serious complications were low for both groups, they were lower for women than for men for both hip and knee replacement, particularly the latter" said Dr. Ravi. "Thus, the previously documented sex difference utilization of TJR cannot be explained by differential risks of complications following surgery." 

Men in the study were found to be up 70 percent more likely to have a heart attack within three months of TJR surgery and 70 percent more likely to have an infection or require revision surgery within two years of a total knee replacement.