Racial Disparities in TKA Complications May Differ Between Unilateral Versus Bilateral Surgeries

Black unilateral total knee arthroplasty (TKA) patients have lower utilization and higher complication rates compared to White unilateral TKA patients. However, it is unknown whether this disparity exists for bilateral TKA as well. The researchers of a study presented at the American College of Rheumatology annual meeting found that while disparities persisted in utilization, they may not in terms of complication rates.

“In our retrospective analysis, we found the utilization rate of bilateral knee replacement was much lower in African American patients compared to white patients,” said Bella Mehta, MBBS, a rheumatologist at the Hospital for Special Surgery (HSS), who presented the findings, according to a press release. “On the other hand, although African Americans having unilateral knee replacement have been shown to have higher in-hospital complication rates compared to white patients, this pattern was not consistent for bilateral knee replacement during the time period we studied.”

The researchers retrospectively reviewed data from the National Inpatient Sample (NIS)- Healthcare Cost and Utilization Project (HCUP) database for White and Black patients who underwent bilateral and unilateral TKA between 2007 and 2016. Patients aged ≥50 years who underwent elective primary surgery were eligible for inclusion. Multivariable logistic regression models were utilized to evaluate racial disparities, adjusting for variables at the individual (age, sex, Elixhauser comorbidity index, and morbid obesity), hospital level (hospital volume, bed size, region and teaching status), and community levels (median household income).

About 276,194 bilateral and 5,528,429 unilateral TKAs were performed during the study period. The proportion of bilateral surgeries decreased from 5.53% in 2007-08 to 4.03% in 2015-16. At the same time points, Black patients, compared to White patients, were much less likely to undergo bilateral surgery; in 2007-08, the rates were 4.68% versus 6.08%, respectively, and in 2015-16, 3.28% versus 4.19%, respectively (trend P<0.001).

When assessing unilateral procedures, Black patients, compared to White patients, had higher rates of in-hospital complications over the course of the study (2007-08, 1.50% vs. 1.35%, respectively; 2015-16, 1.35% vs. 1.00%, respectively; trend P<0.0001). But in bilateral TKA, in-hospital complication rates varied throughout the study. In 2007-08, in-hospital complication rates for Black and White patients were 1.27% and 1.21%, respectively; in 2011-12, 1.08% and 1.03%, respectively; and in 2015-16, 0.92% and 0.86%, respectively (trend P=0.09).

“As we seek to achieve health equity for our patients, we must understand the challenges they face in accessing care, as well as variance in their outcomes,” said study author Michael Parks, MD, an orthopedic surgeon at HSS, according to a press release. “Our ultimate goal is to provide the same quality of care to everyone.”

“Since the complication rate for bilateral knee replacement is not higher for African American patients, health providers should work to provide access to all appropriate patients,” Dr. Mehta commented. She noted that future studies could take a closer look at the patient selection process or assess the role of an individual’s health insurance plan in utilization of the bilateral procedure.