AAOS Now

Published 3/1/2003

Timing a factor in outcomes disparities

Some minority groups wait too long for surgery

The potential for gender and racial disparities is an issue of primary concern for orthopaedic surgeons. According to a poster presentation at the 2009 Annual Meeting, Hispanic and African-American patients tend to have poorer joint function before undergoing hip or knee replacement surgery, and female patients have less preoperative joint function than male patients across ethnic groups.

“Studies have shown that the timing of joint replacement surgery is an important determinant of outcome,” says James Slover, MD, MS, primary author. “This means that patients with worse joint function before surgery do not do as well after the surgery.”

Researchers reviewed the joint function of more than 3,500 hip and knee replacement patients before surgery with physical exams and questionnaires. They used the functional components of the Harris Hip score (HHS) and the Knee Society score (KSS) to quantify the functional ability of all the patients.

Minorities had lower function scores
Among hip replacement patients, African-Americans had an average HHS score that was 4.9 points lower than Caucasian patients (P < 0.0001). Average HHS scores for Hispanic patients undergoing total hip replacement were 8.77 points lower than in Caucasian patients (P < 0.001). Statistically significantly worse preoperative hip function was found in Hispanic men (average HHS 8.8 points lower than Caucasians [P > 0.001]), African-American men (average HHS 5.22 points lower than Caucasians [P > 0.003]), and Hispanic women (average HHS 8.32 points lower than Caucasians [P < 0.001]).

The findings were similar in patients undergoing total knee replacement. African-Americans had an average KSS that was 6.03 points lower than Caucasians (P > 0.06); Hispanic patients had an average score 12.8 points lower than Caucasians (P > 0.001). Hispanic men also had statistically significantly worse preoperative knee function than both African-American (average KSS 18.92 points lower [P < 0.009]) and Caucasian men (average KSS 23.53 points lower [P < 0.006]).

Even when adjusted for the age of the patients, the results showed that the Hispanic and African-American patients had worse joint function before the surgery. In particular, Hispanic men had worse function prior to knee and hip replacement than both African-American and Caucasian men, and Hispanic and African-American women had significantly worse function prior to hip replacement than Caucasian women. Additionally, women demonstrated lower preoperative hip and knee function when compared with men of the same ethnicity.

Reasons for disparities unclear
The reasons for these disparities, Dr. Slover says, are unclear.

“As a next step, we need to try and understand why certain groups tend to wait longer before having surgery,” he says. “Do they have less access to the necessary care? Is it an insurance issue? Is there something in their culture or mindset that makes them wait longer before pursuing treatment? We need to know why this occurs, because if it is an issue of outreach and education, we as orthopaedic surgeons can help address the problem and help patients get the appropriate care and treatment.”

Dr. Slover’s coauthors for “Gender and race characteristics in patients undergoing hip and knee replacement in an urban setting,” include Michael Walsh, PhD, and Joseph D. Zuckerman, MD. They received no compensation for this study.